View allAll Photos Tagged geochemistry
The crust of erosion is always linked to life.
Vladimir Ivanovich Vernadsky.
Vladimir Ivanovich Vernadsky (12 March 1863 – 6 January 1945) was a Russian, Ukrainian and Soviet mineralogist and geochemist who is considered one of the founders of geochemistry, biogeochemistry, and radiogeology, and was a founder of the Ukrainian Academy of Sciences (now National Academy of Sciences of Ukraine). He is most noted for his 1926 book The Biosphere in which he inadvertently worked to popularize Eduard Suess’ 1885 term biosphere, by hypothesizing that life is the geological force that shapes the earth. In 1943 he was awarded the Stalin Prize. Source Wikipedia.
The temple was transferred to the museum from the village of Dorohinka, Fastovsky district, Kyiv region in 1971.
In its appearance, extremely ancient, archaic features have been preserved. There are several assumptions regarding the age of the church. 1600, 1700, 1751 - such dates of its construction are found in various sources (Ukrainian, Russian, Polish). However, experts from the Institute of Environmental Geochemistry of the National Academy of Sciences of Ukraine, according to analyzes, claim that the year of construction is 1528.
The Church of the Archangel Michael is a trident "sailboat", in which the middle "mast" is wider and higher than the side ones. Log cabins made of pine beams are placed in a row from west to east. The eastern frame (altar) is hexagonal, the central one (Nava) and the western one (Babinets) are rectangular. A hipped roof rises above each part of the temple. The baths, as well as the roof, are covered with shingles, and the walls are sheathed with vertical boarding. Each bath is completed with an openwork forged cross.
Церква Архістратига Михаїла найдавніша із чотирьох храмів, розташованих на території музею Пирогово.
Храм перевезено до музею із села Дорогинка Фастівського району Київської області у 1971 році.
У його зовнішньому вигляді збереглися дуже давні, архаїчні особливості. За віком церкви є кілька припущень. 1600, 1700, 1751 роки – такі дати її побудови зустрічаються у різних джерелах (українських, російських, польських). Проте фахівці з Інституту геохімії навколишнього середовища НАН України, за даними аналізів, стверджують, що рік побудови – 1528-й.
Церква Архістратига Михаїла є тризубним «вітрилом», в якому середня «щогла» ширша і вища за бічні. Зруби із соснових брусів поставлені в ряд із заходу на схід. Східний зруб (вівтар) – шестикутний, центральний (нава) та західний (бабинець) – прямокутні. Над кожною частиною храму височить шатровий дах. Лазні, як і дах, покриті гонтом, а стіни обшиті вертикальною тесом. Кожну лазню завершує ажурний кований хрест.
Архангел Михаїл був покровителем княжого роду Ярославовичів (нащадків Ярослава Мудрого).
На честь Архангела Михаїла у 1070р. була побудована перша Михайлівська церква в Києві, на Видубичах, а в 1108р. заснований Михайлівський монастир в центрі Києва.
Архангел Михаїл визнаний покровителем усіх киян та міста Києва..
The temple was transferred to the museum from the village of Dorohinka, Fastovsky district, Kyiv region in 1971.
In its appearance, extremely ancient, archaic features have been preserved. There are several assumptions regarding the age of the church. 1600, 1700, 1751 - such dates of its construction are found in various sources (Ukrainian, Russian, Polish). However, experts from the Institute of Environmental Geochemistry of the National Academy of Sciences of Ukraine, according to analyzes, claim that the year of construction is 1528.
The Church of the Archangel Michael is a trident "sailboat", in which the middle "mast" is wider and higher than the side ones. Log cabins made of pine beams are placed in a row from west to east. The eastern frame (altar) is hexagonal, the central one (Nava) and the western one (Babinets) are rectangular. A hipped roof rises above each part of the temple. The baths, as well as the roof, are covered with shingles, and the walls are sheathed with vertical boarding. Each bath is completed with an openwork forged cross.
Церква Архістратига Михаїла найдавніша із чотирьох храмів, розташованих на території музею Пирогово.
Храм перевезено до музею із села Дорогинка Фастівського району Київської області у 1971 році.
У його зовнішньому вигляді збереглися дуже давні, архаїчні особливості. За віком церкви є кілька припущень. 1600, 1700, 1751 роки – такі дати її побудови зустрічаються у різних джерелах (українських, російських, польських). Проте фахівці з Інституту геохімії навколишнього середовища НАН України, за даними аналізів, стверджують, що рік побудови – 1528-й.
Церква Архістратига Михаїла є тризубним «вітрилом», в якому середня «щогла» ширша і вища за бічні. Зруби із соснових брусів поставлені в ряд із заходу на схід. Східний зруб (вівтар) – шестикутний, центральний (нава) та західний (бабинець) – прямокутні. Над кожною частиною храму височить шатровий дах. Лазні, як і дах, покриті гонтом, а стіни обшиті вертикальною тесом. Кожну лазню завершує ажурний кований хрест.
Архангел Михаїл був покровителем княжого роду Ярославовичів (нащадків Ярослава Мудрого).
На честь Архангела Михаїла у 1070р. була побудована перша Михайлівська церква в Києві, на Видубичах, а в 1108р. заснований Михайлівський монастир в центрі Києва.
Архангел Михаїл визнаний покровителем усіх киян та міста Києва..
A male Northern Bluet damselfly (Enallagma annexum; or is this a familiar bluet??) studies quartz grains in granite next to a subalpine pond. The Northern Bluet damselfly is found near stilwaters throughout most of the U.S. and Canada. The adults hunt small insects. Males establish breeding territories and defend them against other males, which is what this guy was doing in addition to pondering granite geochemistry.
The crew of U.S. Coast Guard Cutter Healy and the Geotraces science team have their portrait taken at the North Pole Sept. 7, 2015. Healy reached the pole on Sept. 5, becoming the first U.S. surface vessel to do so unaccompanied. Healy is underway in support of Geotraces, an international scientific endeavor to study the geochemistry of the world’s oceans. (U.S. Coast Guard photo by Petty Officer 2nd Class Cory J. Mendenhall)
This photo is captured by my Samsung mobile On7.
Celestine Spring is one of the most beautiful hot springs in the Fountain Paint Pot area. No documentation exists of how this spring was named - but its blue color does seem to match the deep azure of the sky.
The science of colors of a hot spring:
[ ttps://www.britannica.com/science/hot-spring]
Many of the colours in hot springs are caused by thermophilic (heat-loving) microorganisms, which include certain types of bacteria, such as cyanobacteria, and species of archaea and algae. Many thermophilic organisms grow in huge colonies called mats that form the colourful scums and slimes on the sides of hot springs. The microorganisms that grow in hot springs derive their energy from various chemicals and metals; potential energy sources include molecular hydrogen, dissolved sulfides, methane, iron, ammonia, and arsenic. In addition to geochemistry, the temperature and pH of hot springs play a central role in determining which organisms inhabit them.
Examples of thermophilic microorganisms found in hot springs include bacteria in the genera Sulfolobus, which can grow at temperatures of up to 90 °C (194 °F), Hydrogenobacter, which grow optimally at temperatures of 85 °C (185 °F), and Thermocrinis, which grow optimally at temperatures of 80 °C (176 °F). Thermophilic algae in hot springs are most abundant at temperatures of 55 °C (131 °F) or below.
Fountain Paint Pot Trail, Yellowstone National Park, USA:
Map (link):
[ www.google.co.in/imgres?imgurl=https://4.bp.blogspot.com/... and Spasm Geysers, Fountain Paint Pot trail, Yellowstone National Park images&ved=0ahUKEwjkgubQv8XeAhUC3Y8KHaFRCQ8QMwhNKBowGg&iact=mrc&uact=8 ]
This part of Lower Geyser Basin seen from a half-mile trail has all four of the hydrothermal features found in the park:
Clepsydra Geyser is a geyser in the Lower Geyser Basin of Yellowstone National Park. Clepsydra plays nearly continuously to heights of 45 feet. The name Clepsydra is derived from the Greek word for water clock. Prior to the 1959 Hebgen Lake earthquake, it erupted regularly every three minutes.
Yellowstone National Park has several hydrothermal areas, so what makes the Fountain Paint Pot Area worth visiting? For starters, this part of Lower Geyser Basin has all four of the hydrothermal features found in the park (mudpots, geysers, hot springs, and fumaroles) and you can see them all from a compact half-mile long boardwalk loop. While none of the many Fountain Paint Pot Area geysers are as famous as Old Faithful, they erupt so frequently that you are almost guaranteed a great show on your short hike. Since the walkway passes all four of Yellowstone’s hydrothermal formations, the hike comes with a guaranteed lesson in hydrothermal volcanism.
Hiking the loop in a clockwise direction, you will first pass through a forest of lodgepole pine snags that were drowned and left lifeless by the surrounding hot springs. As you approach the northwest end of the loop, you will spot a lively collection of geysers. Clepsydra Geyser, Fountain Geyser, Jelly Geyser, Jet Geyser, Morning Geyser, Spasm Geyser, and Twig Geyser erupt with various levels of regularity.
As you progress around the walkway toward the northeast corner, you will pass Red Spouter, which behaves like a fumarole, a hot spring, and a mudpot throughout the year. It is like a hot spring in the winter, a muddy reddish pool in the spring and a steaming fumarole in the drier summer and fall. Wrapping down the east side of the boardwalk, you will pass Leather Pool and a slope of fumaroles. These gaps in the surface whistle and hiss as gasses and steam escape from the ground. Just below the fumaroles, where a little more water is present, the trail circles Fountain Paint Pot. These mudpots bubble and pop as globs of mud springs from the surface like miniature trapeze artists.
Continuing downhill, the hydrothermal features become even wetter as you arrive at Silex Spring. Look down into the small blue pool rimmed with white silica. Water spills over the sides of the spring creating an orange-colored surface covered in rippling runoff. These colors are created by thermophiles, heat-loving microorganisms that live in Yellowstone’s hot springs.
( www.hikespeak.com/trails/fountain-paint-pot-trail-yellows... )
Geothermal features of Yellowstone NP- A brief note:
There are four geothermal features found in the park – Hot springs, Geysers, Fumaroles , and Mud volcanoes/pots.
What is a Hot spring?
Hot spring, also called thermal spring, spring with water at temperatures substantially higher than the air temperature of the surrounding region. Most hot springs discharge groundwater that is heated by shallow intrusions of magma (molten rock) in volcanic areas.
Some thermal springs, however, are not related to volcanic activity. In general, the temperature of rocks within the earth increases with depth. The rate of temperature increase with depth is known as the geothermal gradient. In such cases, the water is heated by convective circulation: groundwater percolating downward reaches depths of a kilometre or more where the temperature of rocks is high because of the normal temperature gradient of the Earth’s crust—about 30 °C / kilometer in the first 10 km. The water from hot springs in non-volcanic areas is heated in this manner.
But in active volcanic zones such as Yellowstone National Park, water may be heated by coming into contact with magma (molten rock). The high temperature gradient near magma may cause water to be heated enough that it boils or becomes superheated. If the water becomes so hot that it builds steam pressure and erupts in a jet above the surface of the Earth, it is called a geyser.
[ Warm springs are sometimes the result of hot and cold springs mixing. They may occur within a volcanic area or outside of one. One example of a non-volcanic warm spring is Warm Springs, Georgia (frequented for its therapeutic effects by paraplegic U.S. President Franklin D. Roosevelt, who built the Little White House there) ].
List of hot springs:
[ en.wikipedia.org/wiki/List_of_hot_springs ]
What is a Geyser?
A geyser is formed when water collecting below the surface is heated by a magma source. When the water boils, it rises to the surface. If the water has an unobstructed path, it will pool on the surface in the form of a steaming hot springs. If the passage of the water is imposed upon, the pressure will increase. When the pressure becomes too great, the water converts into to steam. Steam takes up 1,500 times the volume of water, and at this point, the pressure becomes so intense that the steam and surrounding water droplets shoot out of the ground in geyser form, erupting until the pressure has abated and the process starts all over again.
What is a fumarole?
It’s a vent in the Earth’s surface from which steam and volcanic gases are emitted. The major source of the water vapour emitted by fumaroles is groundwater heated by bodies of magma lying relatively close to the surface. Carbon dioxide, sulfur dioxide, and hydrogen sulfide are usually emitted directly from the magma. Fumaroles are often present on active volcanoes during periods of relative quiet between eruptions.
Fumaroles are closely related to hot springs and geysers. In areas where the water table rises near the surface, fumaroles can become hot springs. A fumarole rich in sulfur gases is called a solfatara; a fumarole rich in carbon dioxide is called a mofette. If the hot water of a spring only reaches the surface in the form of steam, it is called a fumarole. [ www.britannica.com/science/fumarole ]
What is a mud volcano/ mud pot/ paint pot?
Usually mud volcanoes are created by hot-spring activity where large amounts of gas and small amounts of water react chemically with the surrounding rocks and form a boiling mud.
Geo-chemistry of mud volcano: Hydrogen sulfide gas rising from magma chamber, as in Yellowstone’s, causes the rotten-egg smell. Microorganisms, or thermophiles, use this gas as a source of energy, and then help turn the gas into sulfuric acid. The acid then breaks down the rocks and soil into mud. Many of the colors seen are vast communities of thermophiles, but some of the yellow is pure sulfur. When iron mixes with sulfur to form iron sulfide, gray and black swirls sometimes appear in the mud (From description of the display board in the park).
If the water of a hot spring is mixed with mud and clay, it is called a mud pot. Variations are the porridge pot (a basin of boiling mud that erodes chunks of the surrounding rock) and the paint pot (a basin of boiling mud that is tinted yellow, green, or blue by minerals from the surrounding rocks).
There are other mud volcanoes, entirely of a nonigneous origin, occur only in oil-field regions that are relatively young and have soft, unconsolidated formations.
Sources: [ www.britannica.com/science/mud-volcano ], and display boards of the YNP.
Mercury, our smallest planetary neighbor, has very little to call an atmosphere, but it does have a strange weather pattern: morning micro-meteor showers.
Recent modeling along with previously published results from NASA’s MESSENGER spacecraft — short for Mercury Surface, Space Environment, Geochemistry and Ranging, a mission that observed Mercury from 2011 to 2015 — has shed new light on how certain types of comets influence the lopsided bombardment of Mercury’s surface by tiny dust particles called micrometeoroids. This study also gave new insight into how these micrometeoroid showers can shape Mercury’s very thin atmosphere, called an exosphere.
The research, led by Petr Pokorný, Menelaos Sarantos and Diego Janches of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, simulated the variations in meteoroid impacts, revealing surprising patterns in the time of day impacts occur. These findings were reported in The Astrophysical Journal Letters on June 19, 2017.
Here, data from the Mercury Atmosphere and Surface Composition Spectrometer, or MASCS, instrument is overlain on the mosaic from the Mercury Dual Imaging System, or MDIS.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
My companion thought a short walk was in order. I took my cue to put on a pair of sneakers and left my newly repaired lens and cameras at home, assuming we were going for a stroll. It's never that simple. They're rarely seen when they aren't well tooled. Whether it's a medium format film camera, an Olympus, Pentax, Canon, Sony or Nikon; mirrorless, SLR or DSLR. There'll be something within reach.
They are of a scientific bent. A good observer, currently a geochronologist, I believe, despite a penchant for herpetology and years in geochemistry. Did I mention photography? Anyway, today they turned up with a full frame Nikon mated to a 300mm manual lens. I had my hands in my pockets.
Putting those observational skills to good use, they pulled up short and pointed up the slope — they'd spotted something. Monotreme extreme; it's a pocket-sized echidna!!
Normal posture for an echidna encounter is for the wee beastie to dig in, and knowing it can't see you, you can't see it. This one had missed that class and carried on feeding among the leaf litter. While the photographer was snapping away I risked a closer approach, pulling my hand from my pockets to reveal something much smaller than their burden.
After my squat put me within shooting range, this little fellow, who I'd assumed would now freeze, came over to see, perhaps, if I was edible or at least a good conversationalist. I can't say that this is something I've ever seen in echidna behaviour. Still, it seems to have turned out alright for us both: we had a short interaction, they came over to investigate my leg, decided it was neither a threat nor a snack, then got on about their brunch.
This is perhaps my favoured of the two photographs I managed. By the second, as they moved towards me, I suspect I was hyperventilating. You'll see them both, SOOC too, because I don't think I can improve on Nature…
There is never a dull day for participants of the CAVES campaign, ESA’s field training adventure that hones the communication, problem solving and teamwork skills an international crew will need to explore the tough, uncharted terrain of the Moon and Mars.
This week six astronauts turned ‘cavenauts’ from five space agencies headed underground in Slovenia, where they are currently living and working for the week. To keep the element of exploration, astronauts themselves do not know the exact location.
The goal is to run scientific experiments while managing the psychological toll of being in an extreme environment with a multinational crew.
Following a week’s training above ground, including lectures from experts and practical exercises, the team is now underground searching for signs of life that have adapted to the extreme conditions in the caves.
One of the team’s main scientific objectives is to follow the water, a vital resource on- and off- our planet.
Caves are usually formed by running water and ESA picked a cave where rivers flow underground for this training expedition. For the first time, the team will be on the lookout for microplastics. They will also test water chemistry and learn to find and interpret waterways in a cave system.
Trainees are also sampling and analysing microbes that have managed to survive in such inhospitable conditions. Geochemistry, meteorology and other environmental studies are on the list. Read more about the science happening beneath the surface.
If it sounds like a lot to ask of astronauts in a two-week period, fear not. The cavenauts are well prepared and supported.
The astronauts are also using an upgraded version of the Electronic Field Book. This all-in-one, easy-to-use application will allow them to deliver science and video logs while checking procedures and cue cards on a tablet.
Above ground, mission control will track their progress with a 3D map generated on the app as they explore the cave. Scientists can locate the astronauts’ scientific observations paired with pictures, and send their comments back to the cave.
The six cavenauts of this edition of CAVES are ESA astronaut Alexander Gerst, NASA astronauts Joe Acaba and Jeanette Epps, Roscosmos’ cosmonaut Nikolai Chub, Canadian Space Agency astronaut Josh Kutryk and JAXA’s Takuya Onishi. Chub and Gerst are serving as co-commanders of the expedition.
Credits: ESA–A. Romeo
The "Salinelle dello Stadio" of Paternò are active mud volcanoes at the south base of Etna, whose activity is in direct correlation with the volcano Etna itself. They are a phenomenon of secondary volcanism.
More info at wwwold.comune.paterno.ct.it/ambiente/salinelle.htm
(Last updated on December 24, 2025)
Taken, I think, in the Rhododendron Bridge locale of the Mohonk Preserve. Here a number of hiking trails converge just south of Eagle Cliff.
If this stream has a name, it does not appear on the US National Map Viewer or the Mohonk Preserve trail map (see references, below) do not list it.
One of the best ways to disappoint a classful of college Earth-science students is to bring up the subject of joints—only to reveal that you're talking about fractures in rock where no appreciable displacement has occurred on either side. The sense of letdown is palpable.
Here in the Mohonk Preserve near New Paltz, the Silurian-period Shawangunk Formation (mostly white-quartz conglomerate and sandstone) contains a series of joints, including those oriented more or less vertically.
These may have formed when the beds now at the surface were relieved of the weight of overlying rock units when the latter were eroded away. In other words, the stone could have simply stretched when no longer under confining pressure. (This process of upward expansion causing sideways shrinking and cracking is known as the Poisson Effect.)
Alternatively, contraction caused by the beds cooling as they neared the surface may been an important factor. And other tectonic stresses and physical factors might have contributed to the fracturing as well.
Like most streams, this one seeks the least path of resistance and whenever possible uses these channels in the rocky surface. And in time it widens the fractures considerably.
Sources Consulted for This Essay
- Epstein, Jack B. Stratigraphy of Silurian Rocks in Shawangunk Mountain, Southeastern New York, Including a Historical Review of Nomenclature. U.S. Geological Survey Bulletin 1839-L. Washington, DC: United States Government Printing Office, 1993.
- Feldman, Howard R., Jack B. Epstein, and John A. Smoliga. “The Shawangunk and Martinsburg Formations Revisited: Sedimentology, Stratigraphy, Mineralogy, Geochemistry, Structure and Paleontology.” In New York State Geological Association 81st Annual Meeting Field Trip Guidebook, Frederick W. Vollmer, ed. New Paltz, NY’ SUNY New Paltz, 2009.
- Mohonk Preserve. Undercliff-Overcliff Trail Map. Accessed October 6, 2022. www.mohonkpreserve.org/wp-content/uploads/2021/07/WT_Sugg...
- Schimmrich, Steven. Geology of the Hudson Valley: A Billion Years of History. Self-published by Steven Schimmrich, 2020.
- United States Geological Survey. National Map Viewer. Accessed December 24, 2025. apps.nationalmap.gov/viewer/.
To see the other photos and descriptions in this set, visit my my Geologizing a Cuesta album.
Fire flies and the faint light of the Milky Way’s core illuminate the old growth pine forest shoreline of Deming Lake in Itasca State Park near Lake Alice, Minnesota.
A meromictic kettle lake well known to science, Deming Lake has been subject to an extensive amount of research over the years, advancing knowledge in the fields of ecology, paleoecology, limnology, and geochemistry.
On August 3, 2004, NASA’s Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) spacecraft began a seven-year journey, spiraling through the inner solar system to Mercury. One year after launch, the spacecraft zipped around Earth, getting an orbit correction from Earth’s gravity and getting a chance to test its instruments on a familiar planet.
The top image is a view of South America and portions of North America and Africa from MESSENGER’s Dual Imaging System’s. The wide-angle camera records light at eleven different wavelengths, including visible and infrared light. Combining blue, red, and green light results in a true-color image from the observations.
The image above substitutes infrared light for blue light in the three-band combination. The resulting image is crisper than the natural color version because our atmosphere scatters blue light. Infrared light, however, passes through the atmosphere with relatively little scattering and allows a clearer view. That wavelength substitution makes plants appear red. Why? Plants reflect near-infrared light more strongly than either red or green, and in this band combination, near-infrared is assigned to look red.
Apart from getting a clearer image, the substitution reveals more information than natural color. Healthy plants reflect more near-infrared light than stressed plants, so bright red indicates dense, growing foliage. For this reason, biologists and ecologists occasionally use infrared cameras to photograph forests. The second photo shows Mount Sheridan in Yellowstone National Park in infrared light. Healthy pine forests are bright red, while less healthy trees are very dark.
To learn more about how scientists create images from both visible and infrared observations go to: earthobservatory.nasa.gov/Features/FalseColor/
(NASA image based on data from the Mercury Dual Imaging System (MDIS) on Messenger. Yellowstone photograph courtesy National Park Service.) Caption by Holli Riebeek.
Instrument: MESSENGER
Credit: NASA Earth Observatory
NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission.
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(Updated on May 15, 2025)
This spot is tucked under the east-facing escarpment (steep face) of the Shawangunk Ridge cuesta, in the Mohonk Preserve near New Paltz. It's situated along the old Undercliff Carriage Road.
Tourists, city slickers, and outlander geologists, beware: this locale's spoken name is compressed into just two syllables, and is pronounced something like a half-swallowed version of "SHON-gum."
The Silurian-period Shawangunk Formation encompasses clastic sedimentary rocks of varying grain sizes, but its quartz-pebble conglomerate form is one of the most striking rock types I've ever seen. Check out this close-up.
Slump blocks are detached sections of former bedrock—sometimes huge and human-dwarfing, as here—that have fallen downslope and often come to rest in orientations much different than their original slope and dip. They're a common sight below cuesta scarps.
Sources Consulted for This Essay
- Epstein, Jack B. Stratigraphy of Silurian Rocks in Shawangunk Mountain, Southeastern New York, Including a Historical Review of Nomenclature. U.S. Geological Survey Bulletin 1839-L. Washington, DC: United States Government Printing Office, 1993.
- Feldman, Howard R., Jack B. Epstein, and John A. Smoliga. “The Shawangunk and Martinsburg Formations Revisited: Sedimentology, Stratigraphy, Mineralogy, Geochemistry, Structure and Paleontology.” In New York State Geological Association 81st Annual Meeting Field Trip Guidebook, Frederick W. Vollmer, ed. New Paltz, NY’ SUNY New Paltz, 2009.
- Mohonk Preserve. Undercliff-Overcliff Trail Map. Accessed October 6, 2022. www.mohonkpreserve.org/wp-content/uploads/2021/07/WT_Sugg...
- Schimmrich, Steven. Geology of the Hudson Valley: A Billion Years of History. Self-published by Steven Schimmrich, 2020.
- United States Geological Survey. National Map Viewer. Accessed December 24, 2025. apps.nationalmap.gov/viewer/.
To see the other photos and descriptions in this set, visit my my Geologizing a Cuesta album.
This week in 2004, the MErcury Surface, Space ENvironment, Geochemistry, and Ranging spacecraft was launched aboard a Delta II rocket from Cape Canaveral Air Force Station in Florida. Designed and built by the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, MESSENGER was the first spacecraft to orbit Mercury. Protected from the intense heat of the Sun by an innovative ceramic-cloth sunshade, MESSENGER provided the first images of the entire planet and collected information on the composition and structure of Mercury's crust, geologic history, atmosphere, magnetosphere, and the makeup of its core and polar materials. The spacecraft arrived at Mercury on March 17, 2011, and impacted the planet's surface April 30, 2015. MESSENGER was part of the Discovery program, managed at NASA's Marshall Space Flight Center for the agency's Science Mission Directorate. The NASA History Program is responsible for generating, disseminating, and preserving NASA's remarkable history and providing a comprehensive understanding of the institutional, cultural, social, political, economic, technological, and scientific aspects of NASA's activities in aeronautics and space. For more pictures like this one and to connect to NASA's history, visit the Marshall History Program's webpage.
Image credit: NASA
Fountain Paint Pot trail, Yellowstone National Park, Wyoming, USA
Map (link):
[ www.google.co.in/imgres?imgurl=https://4.bp.blogspot.com/... and Spasm Geysers, Fountain Paint Pot trail, Yellowstone National Park images&ved=0ahUKEwjkgubQv8XeAhUC3Y8KHaFRCQ8QMwhNKBowGg&iact=mrc&uact=8 ]
This part of Lower Geyser Basin seen from a half-mile trail has all four of the hydrothermal features found in the park:
Clepsydra Geyser is a geyser in the Lower Geyser Basin of Yellowstone National Park. Clepsydra plays nearly continuously to heights of 45 feet. The name Clepsydra is derived from the Greek word for water clock. Prior to the 1959 Hebgen Lake earthquake, it erupted regularly every three minutes.
Yellowstone National Park has several hydrothermal areas, so what makes the Fountain Paint Pot Area worth visiting? For starters, this part of Lower Geyser Basin has all four of the hydrothermal features found in the park (mudpots, geysers, hot springs, and fumaroles) and you can see them all from a compact half-mile long boardwalk loop. While none of the many Fountain Paint Pot Area geysers are as famous as Old Faithful, they erupt so frequently that you are almost guaranteed a great show on your short hike. Since the walkway passes all four of Yellowstone’s hydrothermal formations, the hike comes with a guaranteed lesson in hydrothermal volcanism.
Hiking the loop in a clockwise direction, you will first pass through a forest of lodgepole pine snags that were drowned and left lifeless by the surrounding hot springs. As you approach the northwest end of the loop, you will spot a lively collection of geysers. Clepsydra Geyser, Fountain Geyser, Jelly Geyser, Jet Geyser, Morning Geyser, Spasm Geyser, and Twig Geyser erupt with various levels of regularity.
As you progress around the walkway toward the northeast corner, you will pass Red Spouter, which behaves like a fumarole, a hot spring, and a mudpot throughout the year. It is like a hot spring in the winter, a muddy reddish pool in the spring and a steaming fumarole in the drier summer and fall. Wrapping down the east side of the boardwalk, you will pass Leather Pool and a slope of fumaroles. These gaps in the surface whistle and hiss as gasses and steam escape from the ground. Just below the fumaroles, where a little more water is present, the trail circles Fountain Paint Pot. These mudpots bubble and pop as globs of mud springs from the surface like miniature trapeze artists.
Continuing downhill, the hydrothermal features become even wetter as you arrive at Silex Spring. Look down into the small blue pool rimmed with white silica. Water spills over the sides of the spring creating an orange-colored surface covered in rippling runoff. These colors are created by thermophiles, heat-loving microorganisms that live in Yellowstone’s hot springs.
( www.hikespeak.com/trails/fountain-paint-pot-trail-yellows... )
Geothermal features of Yellowstone NP- A brief note:
There are four geothermal features found in the park – Hot springs, Geysers, Fumaroles , and Mud volcanoes/pots.
What is a Hot spring?
Hot spring, also called thermal spring, spring with water at temperatures substantially higher than the air temperature of the surrounding region. Most hot springs discharge groundwater that is heated by shallow intrusions of magma (molten rock) in volcanic areas.
Some thermal springs, however, are not related to volcanic activity. In general, the temperature of rocks within the earth increases with depth. The rate of temperature increase with depth is known as the geothermal gradient. In such cases, the water is heated by convective circulation: groundwater percolating downward reaches depths of a kilometre or more where the temperature of rocks is high because of the normal temperature gradient of the Earth’s crust—about 30 °C / kilometer in the first 10 km. The water from hot springs in non-volcanic areas is heated in this manner.
But in active volcanic zones such as Yellowstone National Park, water may be heated by coming into contact with magma (molten rock). The high temperature gradient near magma may cause water to be heated enough that it boils or becomes superheated. If the water becomes so hot that it builds steam pressure and erupts in a jet above the surface of the Earth, it is called a geyser.
[ Warm springs are sometimes the result of hot and cold springs mixing. They may occur within a volcanic area or outside of one. One example of a non-volcanic warm spring is Warm Springs, Georgia (frequented for its therapeutic effects by paraplegic U.S. President Franklin D. Roosevelt, who built the Little White House there) ].
List of hot springs:
[ en.wikipedia.org/wiki/List_of_hot_springs ]
The science of colors of a hot spring:
[ ttps://www.britannica.com/science/hot-spring]
Many of the colours in hot springs are caused by thermophilic (heat-loving) microorganisms, which include certain types of bacteria, such as cyanobacteria, and species of archaea and algae. Many thermophilic organisms grow in huge colonies called mats that form the colourful scums and slimes on the sides of hot springs. The microorganisms that grow in hot springs derive their energy from various chemicals and metals; potential energy sources include molecular hydrogen, dissolved sulfides, methane, iron, ammonia, and arsenic. In addition to geochemistry, the temperature and pH of hot springs play a central role in determining which organisms inhabit them.
Examples of thermophilic microorganisms found in hot springs include bacteria in the genera Sulfolobus, which can grow at temperatures of up to 90 °C (194 °F), Hydrogenobacter, which grow optimally at temperatures of 85 °C (185 °F), and Thermocrinis, which grow optimally at temperatures of 80 °C (176 °F). Thermophilic algae in hot springs are most abundant at temperatures of 55 °C (131 °F) or below.
What is a Geyser?
A geyser is formed when water collecting below the surface is heated by a magma source. When the water boils, it rises to the surface. If the water has an unobstructed path, it will pool on the surface in the form of a steaming hot springs. If the passage of the water is imposed upon, the pressure will increase. When the pressure becomes too great, the water converts into to steam. Steam takes up 1,500 times the volume of water, and at this point, the pressure becomes so intense that the steam and surrounding water droplets shoot out of the ground in geyser form, erupting until the pressure has abated and the process starts all over again.
What is a fumarole?
It’s a vent in the Earth’s surface from which steam and volcanic gases are emitted. The major source of the water vapour emitted by fumaroles is groundwater heated by bodies of magma lying relatively close to the surface. Carbon dioxide, sulfur dioxide, and hydrogen sulfide are usually emitted directly from the magma. Fumaroles are often present on active volcanoes during periods of relative quiet between eruptions.
Fumaroles are closely related to hot springs and geysers. In areas where the water table rises near the surface, fumaroles can become hot springs. A fumarole rich in sulfur gases is called a solfatara; a fumarole rich in carbon dioxide is called a mofette. If the hot water of a spring only reaches the surface in the form of steam, it is called a fumarole. [ www.britannica.com/science/fumarole ]
What is a mud volcano/ mud pot/ paint pot?
Usually mud volcanoes are created by hot-spring activity where large amounts of gas and small amounts of water react chemically with the surrounding rocks and form a boiling mud.
Geo-chemistry of mud volcano: Hydrogen sulfide gas rising from magma chamber, as in Yellowstone’s, causes the rotten-egg smell. Microorganisms, or thermophiles, use this gas as a source of energy, and then help turn the gas into sulfuric acid. The acid then breaks down the rocks and soil into mud. Many of the colors seen are vast communities of thermophiles, but some of the yellow is pure sulfur. When iron mixes with sulfur to form iron sulfide, gray and black swirls sometimes appear in the mud (From description of the display board in the park).
If the water of a hot spring is mixed with mud and clay, it is called a mud pot. Variations are the porridge pot (a basin of boiling mud that erodes chunks of the surrounding rock) and the paint pot (a basin of boiling mud that is tinted yellow, green, or blue by minerals from the surrounding rocks).
There are other mud volcanoes, entirely of a nonigneous origin, occur only in oil-field regions that are relatively young and have soft, unconsolidated formations.
Sources: [ www.britannica.com/science/mud-volcano ], and display boards of the YNP.
A quick overview of YNP
Yellowstone National Park is an American national park located in Wyoming, Montana, and Idaho. Approximately 96 percent of the land area of Yellowstone National Park is located within the state of Wyoming. The Park spans an area of 8,983 km2 comprising lakes, canyons, rivers and mountain ranges. The park is known for its wildlife and its many geothermal features. It has many types of ecosystems, but the subalpine forest is the most abundant. It is part of the South Central Rockies forests eco-region.
It was established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the U.S. and is also widely held to be the first national park in the world. Native Americans have lived in the Yellowstone region for at least 11,000 years. Aside from visits by mountain -men during the early to mid-19th century, organized exploration did not begin until the late 1860s.
The park contains the headwaters of the Yellowstone River, from which it takes its historical name. Although it is commonly believed that the river was named for the yellow rocks seen in the ‘Grand Canyon of the Yellowstone’, the Native American name source is unclear.
Yellowstone Lake is one of the largest high-elevation lakes in North America and is centered over the Yellowstone Caldera, the largest supervolcano on the continent. The caldera is considered as an active volcano. It has erupted with tremendous force several times in the last two million year. The Yellowstone Caldera is the largest volcanic system in North America. It has been termed a "supervolcano" because the caldera was formed by exceptionally large explosive eruptions. The magma chamber that lies under Yellowstone is estimated to be a single connected chamber, about 60 km long, 29 km wide, and 5 to 12 km deep. Yellowstone Lake is up to 400 feet deep and has 180 km of shoreline.The lake is at an elevation of 7,733 feet above sea levels. Half of the world's geysers and hydrothermal features are there in Yellowstone, fueled by this ongoing volcanism. Lava and rocks from volcanic eruptions cover most of the land area of Yellowstone. The park is the centerpiece of the Greater Yellowstone Ecosystem, the largest remaining nearly-intact ecosystem in the Earth's northern temperate zone. In 1978, Yellowstone was named a UNESCO World Heritage Site.
In May 2001, the U.S. Geological Survey, Yellowstone National Park, and the University of Utah created the Yellowstone Volcano Observatory (YVO), a partnership for long-term monitoring of the geological processes of the Yellowstone Plateau volcanic field, for disseminating information concerning the potential hazards of this geologically active region.
Hundreds of species of mammals, birds, fish, and reptiles have been documented, including several that are either endangered or threatened. The vast forests and grasslands also include unique species of plants. Yellowstone Park is the largest and most famous mega fauna location in the contiguous United States. Grizzly bears, wolves, and free-ranging herds of bison and elk live in this park. The Yellowstone Park bison herd is the oldest and largest public bison herd in the United States.
Forest fires occur in the park each year. In the largest forest fires of 1988, nearly one third of the park was burnt.
Yellowstone has numerous recreational opportunities, including hiking, camping, boating, fishing and sightseeing. Paved roads provide close access to the major geothermal areas as well as some of the lakes and waterfalls. During the winter, visitors often access the park by way of guided tours that use either snow coaches or snowmobiles.
Fire in Yellowstone NP:
Causes of wildfire in Yellowstone NP
Wildfire has had a role in the dynamics of Yellowstone’s ecosystems for thousands of years. Although many fires were caused by human activities, most ignitions were natural. The term "natural ignition" usually refers to a lightning strike. Afternoon thunderstorms occur frequently in the northern Rocky Mountains but release little precipitation, a condition known as ‘dry lightning’. In a typical season there are thousands of lightning strikes in Yellowstone. Lightning strikes are powerful enough to rip strips of bark off of a tree in a shower of sparks and blow the pieces up to 100 feet away. However, most lightning strikes do not result in a wildfire because fuels are not in a combustible state.
The great fire incidence of 1988
The Yellowstone fires of 1988 collectively formed the largest wildfire in the recorded history of Yellowstone National Park in the United States. Starting as many smaller individual fires, the flames quickly spread out of control due to drought conditions and increasing winds, combining into one large conflagration which burned for several months. The fires almost destroyed two major visitor destinations and, on September 8, 1988, the entire park closed to all non-emergency personnel for the first time in its history. Only the arrival of cool and moist weather in the late autumn brought the fires to an end. A total of 793,880 acres, or 36 percent of the park was affected by the wildfires.
Fire incidence, 2016
As of September 21, 2016, 22 fires (human and lightning-caused) have burned more than 62,000 acres in Yellowstone National Park, making it the highest number of acres burned since the historic 1988 fire.
Heritage and Research Center
The Heritage and Research Center is located at Gardiner, Montana, near the north entrance to the park. The center is home to the Yellowstone National Park's museum collection, archives, research library, historian, archeology lab, and herbarium. The Yellowstone National Park Archives maintain collections of historical records of Yellowstone and the National Park Service. The collection includes the administrative records of Yellowstone, as well as resource management records, records from major projects, and donated manuscripts and personal papers. The archives are affiliated with the National Archives and Records Administration.
The "Salinelle dello Stadio" of Paternò are active mud volcanoes at the south base of Etna, whose activity is in direct correlation with the volcano Etna itself. They are a phenomenon of secondary volcanism.
More info at wwwold.comune.paterno.ct.it/ambiente/salinelle.htm
This series complements my award-winning guidebook, Chicago in Stone and Clay: A Guide to the Windy City's Architectural Geology. Henceforth I'll just call it CSC.
The CSC section and page reference for the building featured here: 15.8; pp. 246-249.
Looking northwestward at the eastern and southern elevations.
Of the many fine late-nineteenth-century residences still on view in the Windy City, the Richardsonian Romanesque Rickcords House in the Gold Coast neighborhood holds the distinction of being a rare surviving example of the use of that hardest of architectural stones, the Montello Granite.
The Montello, quarried in the central-Wisconsin town of that name, formed from a body of magma associated with a violent eruptive event in the Paleoproterozoic era, about 1.76 Ga ago. This cataclysmic episode in the complex geologic history of the Badger State blanketed its region with rhyolite and welded tuff (fused volcanic ash). Apparently it was triggered not by the usual process of plate convergence, but by crustal thinning—possibly caused by a process known as slab rollback.
While the particular mass of molten rock that became the granite did not reach the surface before it cooled, its geochemistry is essentally the same as that of the extrusive material that did. What makes the Montello Granite both so hard to work and so durable is its abnormally high quartz content. It was also favored—and much more frequently used—for monuments and cemetery headstones.
For considerably more on this site, get and read Chicago in Stone and Clay, described at its Cornell University Press webpage.
The other photos and discussions in this series can be found in my "Chicago in Stone and Clay" Companion album. In addition, you'll find other relevant images and descriptions in my Architectural Geology: Chicago album.
It’s quite moving to hold a piece of Mars in your hands… to reflect on its incredible interplanetary journey, and the science that gives confidence as to the origin of this unusual piece of rock.
This is the 2kg main mass of DaG 1037, an igneous Martian shergottite meteorite discovered in 1999 in the Dar al Gani desert of Libya. Meteorites are often found in North West Africa, not because they land there more often, but because they are easy to spot as peculiar objects in the desert sands. (It’s like searching for your car keys where the streetlight shines bright).
"DaG 1037 is one of the most important of the very few Martian meteorites that have been discovered and scientifically classified to date. It contains large shock-melt veins, gas vesicles and shock-altered olivine, indicating that it was very close to, if not precisely at, the impact site of an asteroid which occurred approximately 175 million years ago on the planet Mars, and was the likely source of almost all known Martian meteorites. The composition of this particular specimen includes basalt, cooled lava rich with iron and magnesium, indicating that there was active volcanism on Mars 474 million years ago, proof that it was a living planet, unlike the dead rock of the Moon. Indeed, the early Martian atmosphere was much thicker, warmer and wetter than it is today, possibly even capable of sustaining life." — Heritage 2011
"Unlike lunar meteorites where there are believed to be upwards of 35 source impact sites, most Martian meteorites are believed to be from one asteroid impact/source crater. The only way the surface rock could have been ejected into space from the surface of Mars, would be as a result of a huge asteroid impact on the planet's surface; the energy required to reach escape velocity is so enormous that normal meteorite impacts or volcanic explosions would not provide enough energy release. Such a huge asteroid impact would have had a catastrophic effect on the Martian environment and may be the cause of the loss of the Martian atmosphere and the disappearance of its surface water and possibly life. So, these few meteorites from Mars may provide mute testament to the destruction of the Martian environment and extinction of its life forms." — Heritage 2008
From the geochemistry and various isotopes, we can deduce the origin and transit time of interstellar objects (a bit like Carbon-14 dating for formerly living artifacts on Earth). The meteorites from Mars exhibit precise elemental and isotopic compositions similar to rocks and atmosphere gases analyzed by spacecraft on Mars, starting with the Viking lander in 1976. Compared to other meteorites, the Martians have younger formation ages, unique oxygen isotopic composition (consistent for Mars and not for Earth, a unique signature for each planet), and the presence of aqueous weathering products. A trapped gas analysis concluded that their origin was Mars quite recently, in the year 2000.
It's igneous rock with large olivine megacrysts in a fine-grained groundmass of pyroxene and maskelynite; with Ti-rich chromite, sulfides, phosphates, and Fe-rich olivines.
This one reminds me of the rocks strewn about on the surface of Mars. Because its fusion crust (the common thin black exterior formed from the heat of Earth's atmosphere on entry at Mach 25) was sandblasted away in the Libyan desert, it looks more like it would have on Mars. It looks like it came out of one of the rock strewn fields in the earliest color photos from the Mars lander.
The size claim is as of 2015. Not sure what has been found since.
It is the latest addition to the Space Museum at work.
Some days when you're travelling are just a chore — especially in a group. Others are interesting in a touristy kind of way — if you can switch off the group. But today is truly exciting. Today the group is GONE, I'm refreshed by North Ronaldsay and about to execute a rough plan that will deliver long held ambitions. Driving where and when I please I'll skirt the coast west of Kirkwall and then via the Stones of Stennes, cross between the Loch of Harray and the Loch of Stennes to the Ring of Brodgar, on to the legendary Skara Brae and pop in on Unstan Chambered Cairn. Thus fulfilled, tired and happy I'll return to Kirkwall to see what urban adventures it can share. Honestly it's not that well planned. What you just read is a record of what came of travelling, in part, aimlessly about and discovering the Mainland of Orkney along the way — another archipelago!!!
Don't ask me for a chronology of Neolithic structures on Orkney. Let's say they are old and accept that reliable dates for some of them don't or can't exist. My reasoning includes the very real likelihood that these things were built in multiple phases or over a long time. Even the fabulous Stonehenge is like that and just out of interest, the last recognised phase of building at Stonehenge, the one preceding the 1950s reconstruction, is younger than the youngest dates proposed for the places I'm visiting. It isn't just that chronology which now makes archaeologists point to the north for an origin of the great stone monuments. Isotope geochemistry has revealed a lot about southward movements. I'm interested in this because when I visited Stonehenge the archaeologist asked a simple question: how do we know they were smart? His answer: because they were your ancestors. It's true that my Wiltshire ancestry put me near Stonehenge. It might be a stretch, overreach even, to suppose that lineage stretches back over 5000 years to Neolithic Orkney. But one thing is for certain, we all have genes going back that far and further so as improbable as it is, it is a possibility.
I'm beginning this monumental day at the Stones of Stennes for no other reason than it's nearest to Kirkwall. Coincidentally, it is thought to be the oldest henge structure in Britain. I'll now reveal something which might make some a little squeamish. During the last Ice Age all human life in Britain was extinguished. As the ice began to retreat but before the sea level rose, Mesolithic people made their way from Europe to what is now Orkney — about 9000 yrs ago. Not a lot is preserved because they didn't build like their successors and back then, Orkney was a single landmass. The melting ice changed all that and drowned a lot of land where Mesolithic people likely lived. Despite the hubris of Brexit, the British were exquisitely European.
New people with new tools, new livestock, a culture of cropping and permanent settlement arrived about 6000 years ago — Neolithic settlers. It has been reasoned that their practices destroyed Orkney's tree cover necessitating their adoption of stone as a building material. Those durable materials are why we have so much physical evidence of how these, our putative British ancestors, lived. So it shouldn't be surprising that here at Stennes, what is preserved is stone.
Now, not all of the supposed twelve Stones of Stennes are preserved. It is rumoured that an outsider came into the community in the early 19th century, started knocking down the stones and breaking them up to build from them. Some of this may be true. I'll let you decide. Now there's really just what you see here. They're big, even if smaller than the stones of Stonehenge. Oh, and what you see here is a partial reconstruction. Apparently the ditch and bank were reconstructed in the 1980s. Nevermind! All of the great cathedrals of Britain are the result of building, building, building, rebuilding, remodelling, renovation, repair and maintenance. Why should this site be any different?
Cave outside the village Froðba in Suðuroy, Faroe Islands
NASA launched the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) interplanetary probe from the Kennedy Space Center on August 3, 2004. The probe was designed to conduct an in-depth study of Mercury. The mission ended on April 30, 2015 when the probe conducted a controlled impact with the planet.
Credit: NASA
Image Number: KSC-04PD-1626
Date: August 3, 2004
Sedimentary rocks are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles (detritus) to settle and accumulate or minerals to precipitate from a solution. Particles that form a sedimentary rock by accumulating are called sediment. Before being deposited, sediment was formed by weathering and erosion in a source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers which are called agents of denudation.
The sedimentary rock cover of the continents of the Earth's crust is extensive, but the total contribution of sedimentary rocks is estimated to be only 8% of the total volume of the crust. Sedimentary rocks are only a thin veneer over a crust consisting mainly of igneous and metamorphic rocks. Sedimentary rocks are deposited in layers as strata, forming a structure called bedding. The study of sedimentary rocks and rock strata provides information about the subsurface that is useful for civil engineering, for example in the construction of roads, houses, tunnels, canals or other structures. Sedimentary rocks are also important sources of natural resources like coal, fossil fuels, drinking water or ores.
The study of the sequence of sedimentary rock strata is the main source for scientific knowledge about the Earth's history, including palaeogeography, paleoclimatology and the history of life. The scientific discipline that studies the properties and origin of sedimentary rocks is called sedimentology. Sedimentology is part of both geology and physical geography and overlaps partly with other disciplines in the Earth sciences, such as pedology, geomorphology, geochemistry and structural geology.
John Pollini in my opinion is the number 1 authority on Julio Claudian Portrait study. I have had much correspondence with Prof. Pollini and he is passionate about Roman Art. Here is his curriculum Vitae:
Education
B.A. Classics, University of Washington, 1/1968
M.A. Ancient History and Mediterranean Archaeology, UC Berkeley, 1/1973
Ph.D. Ancient History and Mediterranean Archaeology, UC Berkeley, 1/1978
Academic Appointment, Affiliation, and Employment History
Professor, Department of Art History (Adjunct Professor for Department of Classics and Department of History), University of Southern California, 1991-
Dean of the School of Fine Arts, University of Southern California, 1993-1996
Chairman of the Department of Art History, University of Southern California, 1990-1993
Associate Professor, Department of Art History and Department of Classics (adjunct appointment), University of Southern California, 1987-1991
Assistant Professor, Department of Classics, Johns Hopkins University, 1980-1987
Curator, Johns Hopkins University Archaeological Museum, 1980-1987
Visiting Assistant Professor, Department of Classics, Johns Hopkins University, 1979-1980
Mellon Postdoctoral Fellow, Department of Classics, Case Western Reserve University, 1978-1979
Description of Research
Summary Statement of Research Interests
Professor Pollini's research is concerned with methodologies of classical art and archaeology, ancient history, classical philology, epigraphy and numismatics. His other scholarly research interests include ancient religion, mythology, narratology, rhetoric and propaganda. Over the years Professor Pollini has excavated at the Greco-Roman site of Aphrodisias, Turkey, and the Etruscan site of Ghiaccio Forte, Italy, and participated in the underwater survey of the port of Tarquinia (Gravisca), Italy. Trained in the methodologies of classical art & archaeology, ancient history, classical philology, epigraphy, and numismatics, Professor Pollini is committed to interdisciplinary teaching and research. Professor Pollini has lectured widely both in the United States and abroad. He has published numerous articles and authored several books.
Research Specialties
Classical Art and Archaeology
Honors and Awards
Elected Life Member, German Archaeological Association, 2000-
American Council of Learned Societies Fellowship, awarded for second time, 2006-2007
Guggenheim Fellowship, deferred until 2007-2008, 2006-2007
Whitehead Professor at the American School of Classical Studies at Athens (Honorific Appointment), 9/1/2006-6/1/2007
Departmental Nominee for University Associates Award for Excellence in Teaching 2002, 2002-2005
Mellon Foundation Award for Excellence in Mentoring, 2004-2005
Departmental Nominee for University Associates Award for Excellence in Teaching 1998, 1998-2001
National Endowment for the Humanities Fellowship, awarded for second time, 1995-1996
American Council of Learned Societies Fellowship, 1987-1988
National Endowment for the Humanities Fellowship, 1983-1984
Mellon Postdoctoral Fellowship, 1978-1979
Fulbright Award, Fellowship to Italy, 1975-1976
CURRICULUM VITAE
JOHN POLLINI
Department of Art History
Von Kleinsmid Center 351 University of Southern California
Los Angeles, CA 90089-0047
Professor of Classical Art and Archaeology, Department of Art History
Joint Professor, Department of History
Adjunct Professor, Department of Classics
President, Classical Archaeological Association of Southern California (CAASC)
DEGREES
Ph. D. Ancient History and Mediterranean Archaeology, University of California at
Berkeley (1978) (interdisciplinary program involving the Departments of Art History,
Classics, and History; major field: Etruscan and Roman Art and Archaeology; minor
fields: Greek Art and Archaeology and Roman History; Ph.D. equivalency exams in
ancient Greek and Latin) [Diss.: Studies in Augustan “Historical” Reliefs]
M.A. Ancient History and Mediterranean Archaeology, University of California at
Berkeley (l973) [MA Thesis: Two Marble Portrait Statues of Pugilists from Carian
Aphrodisias: Iconography and Third Century A.D. Sculptural Traditions in the Roman
East]
B.A. magna cum laude, Classics, University of Washington (1968)
POSTDOCTORAL ACADEMIC APPOINTMENTS
Dean of the School of Fine Arts, University of Southern California, with administrative,
budgetary, and fund-raising responsibilities (1993-1996)
Chairman of the Department of Art History, University of Southern California
(1990-1993)
Full Professor, University of Southern California, Department of Art History
(1991-present), with joint appointment in the Department of History and adjunct
appointment in the Department of Classics
Associate Professor, University of Southern California, Department of Art History, with
adjunct appointment in the Department of Classics (1987-1991)
Assistant Professor, Johns Hopkins University, Department of Classics (1980-1987) and
Curator of the Johns Hopkins University Archaeological Museum (1980-1987)
Visiting Assistant Professor, Johns Hopkins University, Department of Classics
(1979-1980)
Mellon Postdoctoral Fellow, Case Western Reserve University, Department of Classics
(1978-1979)
INTERNATIONAL AND NATIONAL FELLOWSHIPS, GRANTS,
AWARDS, HONORS
William E. Metcalf Lectureship (2008)
John Simon Guggenheim Memorial Foundation Fellowship (2006-2007, deferred to
2007-2008)
Whitehead Professor of Archaeology, American School of Classical Studies at
Athens (2006-2007)
American Council of Learned Societies Fellowship (2006-2007)
Kress Foundation Travel Grant (Summer 2006)
Mellon Foundation Award for Excellence in Mentoring (2005)
Taggart Foundation Grant: Campus Martius Virtual Reality Project (2005)
Distinguished Lecturer, Biblical Archaeological Society and Center for Classical
Archaeology, University of Oklahoma, Norman (2005): Series of three lectures on
Roman and Christian Religion, Art, and Ideology
Kress Foundation Travel Grant (2003)
Senior Humboldt Research Prize (nominated) to Berlin, Germany, for 2000-2001
Elected Member (for life) of the German Archaeological Institute (Berlin) (2000)
National Endowment for the Humanities Fellowship for Independent Study and
Research (1995-1996)
Kress Foundation Travel Grant (Summer 1988)
American Council of Learned Societies Fellowship (1987-1988)
Kress Foundation Travel Grant (1987)
National Endowment for the Humanities Fellowship for Independent Study and
Research (1983-1984)
Mellon Postdoctoral Fellowship, Case Western Reserve University (1978-1979)
Mabelle McLeod Lewis Memorial Fund Fellowship to Italy (1975-1976)
Fulbright Fellowship, Università di Roma, Rome, Italy (1975-1976)
UNIVERSITY FELLOWSHIPS, GRANTS, AWARDS, HONORS
Departmental Nominee for University Associates Award for Excellence in Teaching
(2002-2005)
College Faculty Research Development Award (consecutive years: 2000-2007)
University of Southern California Grant for Innovative Undergraduate Teaching
(with Lynn Swartz Dodd and Nicholas Cipolla) for a virtual reality project “Imaging
Antiquity: Creating Context through Virtual Reconstructions, Digital Resources, and
Traditional Media” (2003-2004)
Grant for the “College Initiative for the Study of Political Violence” (2002)
University of Southern California Grant for Innovative Undergraduate Teaching
(with Bruce Zuckermann and Lynn Swartz Dodd) to develop a new interdisciplinary and
interdepartmental course entitled “Accessing Antiquity: Actual Objects in Virtual Space”
(2000-2001)
University of Southern California Senior Nominee for National Endowment for the
Humanities Summer Stipend for Faculty Research (1998-1999)
Departmental Nominee for University Associates Award for Excellence in Teaching
(1998-2001)
College Awards and Grants for Research Excellence (consecutive years: 1997-2000)
Hewlett Foundation Award and Grant for General Education Course Development
(1997-1998)
Faculty Research and Innovation Fund Grant, University of Southern California (1988)
University of California Traveling Fellowship (1976-1977)
Dean’s Fellowship, U.C. Berkeley (1973-1975)
Phi Beta Kappa (1968), University of Washington
ADDITIONAL EDUCATIONAL PREPARATION
Field trips sponsored by the American Academy in Rome, German Archaeological
Institute, and Comune di Roma (1975-1978)
Research in Rome, Italy for dissertation (1975-1978), as well as further study of Greek
and Roman art and architecture in Italy and elsewhere in Europe during this period
Supervised study of Greek and Roman sculpture at the J. Paul Getty Museum, with
J. Frel (1973-1975)
Course in Greek art and archaeology at the Universität München, Munich, Germany
with E. Homann-Wedeking (1971)
Study of the German language at the Goethe Institute, Grafing (Munich), Germany (1971)
Course work in Roman, Etruscan, and Italic art and architecture, Università di Roma,
with G. Becatti, M. Pallottino, F. Castagnoli, and M. Squarciapino (1970-1971)
ARCHAEOLOGICAL FIELD WORK
Underwater survey of port of Tarquinia (Gravisca), Italy (1977): Consultant
Excavation of Etruscan site of Ghiaccio Forte, Italy (1973)
Excavation of Greco-Roman site of Aphrodisias, Turkey (1970-1972)
Excavation of Spanish/Indian Mission, Guavave, Arizona (1965-1966)
LANGUAGES
Ancient: Latin and Greek
Modern: German, Italian, French, modern Greek, some Turkish
BOOKS
PUBLISHED:
I) The Portraiture of Gaius and Lucius Caesar (Fordham University Press, New York
1987) (with a book subvention from the National Endowment for the Humanities).
II) Roman Portraiture: Images of Character and Virtue, with graduate student
participation (Fisher Gallery, Los Angeles 1990).
III) Gallo-Roman Bronzes and the Process of Romanization:The Cobannus Hoard
(Monumenta Graeca et Romana IX) (Brill, Leiden 2002).
IV) The de Nion Head: A Masterpiece of Archaic Greek Sculpture (Philipp von
Zabern, Mainz 2003).
V) Terra Marique: Studies in Art History and Marine Archaeology in Honor of Anna
Marguerite McCann on the Receipt of the Gold Medal of the Archaeological Institute
of America (editor, designer, and contributor of introduction, publication list, and
one of 19 essays) (Oxbow Publications, Oxford 2005).
SUBMITTED:
VI) From Republic to Empire: Rhetoric, Religion, and Power in the Visual Culture of
Ancient Rome (University of Oklahoma Press), comprising eight chapters:
CHAPTER I: The Leader and the Divine: Diverse Modes of Representation in Roman Numismatics
CHAPTER II: The Cult Image of Julius Caesar: Conflicts in Religious Theology and Ideology in
Augustus’ Representational Program
CHAPTER III: From Warrior to Statesman in Augustan Art and Ideology: Augustus and the Image of
Alexander
CHAPTER IV: The Ideology of “Peace through Victory” and the Ara Pacis: Visual Rhetoric and the
Creation of a Dynastic Narrative [revised and updated essay originally published in
German]
CHAPTER V: The Acanthus of the Ara Pacis as an Apolline and Dionysiac Symbol of
Anamorphosis, Anakyklosis and Numen Mixtum [revised and updated publication].
CHAPTER VI: Divine Providence in Early Imperial Ideology: The Smaller Cancelleria Relief and
the Ara Providentiae Augustae
CHAPTER VII: The “Insanity” of Caligula or the “Insanity” of the Jews? Differences in Perception
and Religious Beliefs
CHAPTER VIII: “Star Power” in Imperial Rome: Astral Theology, Castorian Imagery, and the Dual
Heirs in the Transmission of the Leadership of the State
IN PROGRESS:
VII) Christian Destruction and Desecration of Images of Classical Antiquity: A Study
in Religious Intolerance in the Ancient World
VIII) Dynastic Narratives in Augustan Art and Thought: The Rhetoric and Poetry of
Visual Imagery [with DVD Virtual Reality Program of the Monuments]
IX) The Image of Augustus: Art, Ideology, and the Rhetoric of Leadership
X) Social, Sexual, and Religious Intercourse: Sacrificial Ministrants and Sex-Slaves
in Roman Art -- 3rd Century B.C. - 4th Century A.D.
ARTICLES
PUBLISHED:
1) “A Flavian Relief Portrait in the J. Paul Getty Museum,” in Getty Museum Journal
5 (1977) 63-66.
2) “Gnaeus Domitius Ahenobarbus and the Ravenna Relief,” in Römische Mitteilungen
88 (1981) 117-40.
3) “A Pre-Principate Portrait of Gaius (Caligula)?” in Journal of the Walters Art
Gallery 40 (1982) 1-12.
4) “Damnatio Memoriae in Stone: Two Portraits of Nero Recut to Vespasian in
American Museums,” in American Journal of Archaeology 88 (1984) 547-55.
5) “The Meaning and Date of the Reverse Type of Gaius Caesar on Horseback,” in
American Numismatic Society Museum Notes 30 (1985) 113-17.
6) “Response to E. Judge’s ‘On Judging the Merits of Augustus,’” in Center for
Hermeneutical Studies: Colloquy 49 (1985) 44-46.
7) “Ahenobarbi, Appuleii and Some Others on the Ara Pacis,” in American Journal of
Archaeology 90 (1986) 453-60.
8) “The Findspot of the Statue of Augustus from Prima Porta,” in Bullettino della
Commissione Archeologica Comunale di Roma 92 (1987/88) 103-108.
9) “Two Acrolithic or Pseudo-Acrolithic Sculptures of the Mature Classical Period in
the Archaeological Museum of the Johns Hopkins University,” in Classical Marble:
Geochemistry,Technology, Trade (NATO ASI Series E vol. 153), edd. N. Herz and
M. Waelkens (Dordrecht 1988) 207-17.
10) “Man or God: Divine Assimilation and Imitation in the Late Republic and Early
Principate,” in Between Republic and Empire: Interpretations of Augustus and His
Principate, edd. K.A. Raaflaub and M. Toher (Berkeley 1990) 333-63.
11) “The Marble Type of the Augustus from Prima Porta: An Isotopic Analysis,” in
Journal of Roman Archaeology 5 (1992) 203-208.
12) “The Tazza Farnese: Principe Augusto ‘Redeunt Saturnia Regna’!” in American
Journal of Archaeology 96 (1992) 249-55, 283-300.
13) “The Cartoceto Bronzes: Portraits of a Roman Aristocratic Family of the Late First
Century B.C.,” in American Journal of Archaeology 97 (1993) 423-46.
14) “The Gemma Augustea: Ideology, Rhetorical Imagery, and the Construction of a
Dynastic Narrative,” in Narrative and Event in Ancient Art, ed. P. Holliday
(Cambridge 1993) 258-98.
15) “The Acanthus of the Ara Pacis as an Apolline and Dionysiac Symbol of
Anamorphosis, Anakyklosis and Numen Mixtum,” in Von der Bauforschung zur
Denkmalpflege, Festschrift für Alois Machatschek (Vienna 1993) 181-217.
16) “The ‘Trojan Column’ at USC: Reality or Myth?” in Trojan Family (May, 1994)
30-31.
17) “The Augustus from Prima Porta and the Transformation of the Polykleitan Heroic
Ideal,” in Polykleitos, the Doryphoros, and Tradition, ed. W. Moon (Madison 1995)
262-82.
18) “The ‘Dart Aphrodite’: A New Replica of the ‘Arles Aphrodite Type,’ the Cult Image
of Venus Victrix in Pompey’s Theater at Rome, and Venusian Ideology and Politics
in the Late Republic - Early Principate,” in Latomus 55 (1997) 757-85.
19) “Parian Lychnites and the Prima Porta Statue: New Scientific Tests and the Symbolic
Value of the Marble” (with N. Herz, K. Polikreti, and Y. Maniatis), in Journal of
Roman Archaeology 11 (1998) 275-84.
20) “The Warren Cup: Homoerotic Love and Symposial Rhetoric in Silver,” in The Art
Bulletin 81 (1999) 21-52.
21) “Ein mit Inschriften versehener Legionärshelm von der pannonisch-dakischen Grenze
des römischen Reiches: Besitzverhältnisse an Waffen in der römischen Armee,” in
M. Junkelmann, Römische Helme VIII Sammlung Axel Guttmann, ed. H. Born
(Mainz 2000) 169-88.
22) “The Marble Type of the Statue of Augustus from Prima Porta: Facts and Fallacies,
Lithic Power and Ideology, and Color Symbolism in Roman Art,” in Paria Lithos:
Parian Quarries, Marble and Workshops of Sculpture (Proceedings of the First
International Conference on the Archaeology of Paros and the Cyclades, Paros, 2-5
October 1997), edd. D.U. Schilardi and D. Katsonopoulou (Athens 2000) 237-52.
23) “The Riace Bronzes: New Observations,” in Acten des 14. Internationalen
Kongresses für Antike Bronzen, Kölner Jahrbuch 33 (2000) 37-56.
24) “Two Bronze Portrait Busts of Slave-Boys from a Shrine of Cobannus in Roman
Gaul,” in Studia Varia II: Occasional Papers on Antiquities of The J. Paul Getty
Museum 10 (2001) 115-52.
25) “A New Portrait of Octavian/Augustus Caesar,” in Roman Sculpture in the
Art Museum, Princeton University (Princeton 2001) 6-11.
26) “Two Gallo-Roman Bronze Portraits of Sacrificial Ministrants in the J. Paul Getty
Museum,” in From the Parts to the Whole 2: Acta of the 13th International Bronze
Congress, Cambridge, Massachusetts, May 28 - June 1, 1996, edd. C.C.
Mattusch, A. Brauer, and S.E. Knudsen (Portsmouth, Rhode Island 2002) 89-91.
27) “‘Frieden-durch-Sieg’ Ideologie und die Ara Pacis Augustae: Bildrhetorik und
die Schöpfung einer dynastischen Erzählweise,” in Krieg und Sieg: Narrative
Wanddarstellungen von Altägypten bis ins Mittelalter (Internationales
Kolloquium 23. - 30. Juli 1997 im Schloss Heindorf, Langenlois; Österreichischen
Akademie der Wissenschaften XXIV), edd. M. Bietak und M. Schwarz (Vienna
2002) 137-59.
28) “A New Portrait of Octavia and the Iconography of Octavia Minor and Julia Maior,”
Römische Mitteilungen 109 (2002) 11-42.
29) “Slave-Boys for Sexual and Religious Service: Images of Pleasure and Devotion,” in
Flavian Rome: Culture, Image, Text, edd. A.J. Boyle and W.J. Dominik (Leiden
2003) 149-66.
30) “The Caelian Hill Sacrificial Minister: A Marble Head of an Imperial Slave-Boy from
the Antiquarium Comunale on the Caelian Hill in Rome,” in Römische Mitteilungen
111 (2004) 1-28.
31) “A New Head of Augustus from Herculaneum: A Marble Survivor of a Pyroclastic
Surge,” in Römische Mitteilungen 111 (2004) 283-98.
32) “The Armstrong and Nuffler Heads and the Portraiture of Julius Caesar, Livia, and
Antonia Minor in Terra Marique: Studies in Honor of Anna Marguerite McCann
on the Receipt of the Gold Medal of the Archaeological Institute of America, ed.
J. Pollini (Oxbow Publications, Oxford 2005) 89-122.
33) “A New Marble Portrait of Tiberius: Portrait Typology and Ideology,” in Antike Kunst
48 (2005) 57-72.
34) “A North African Portrait of Caracalla from the Mellerio Collection and the
Iconography of Caracalla and Geta,” in Revue Archéologique (2005) 55-77.
35) “A Bronze Gorgon Handle Ornament of the Ripe Archaic Greek Period,” in Annuario
della Scuola Archeologica Italiana di Atene e delle Missioni Italiani in Oriente 83
(2005) 235-47.
36) “Ritualizing Death in Republican Rome: Memory, Religion, Class Struggle, and the
Wax Ancestral Mask Tradition’s Origin and Influence on Veristic Portraiture” in
Performing Death: Social Analyses of Funerary Ritual in the Ancient Near East
and Mediterranean (Oriental Institute Seminars 3, University of
Chicago), ed. N. Laneri (Chicago 2007) 237-85.
37) “A New Bronze Portrait Bust of Augustus,” in Latomus 66 (2007) 270-73.
FORTHCOMING:
38) “Gods and Emperors in the East: Images of Power and the Power of Intolerance,”
in the proceedings of an international conference on “‘Sculptural Environment’ of the
Roman Near East: Reflections on Culture, Ideology, and Power” (University of
Michigan), in Interdisciplinary Studies in Ancient Culture and Religion,
edd. E.A. Friedland, S.C. Herbert, and Y.Z. Eliav (Peeters Publ.: Leuven).
39) “A New Portrait Bust of Tiberius in the Collection of Michael Bianco,” in Bulletin
Antieke Beschaving 83 (2008) 133-38.
40) “The Desecration and Mutilation of the Parthenon Frieze by Christians and Others,” in
Athenische Mitteilungen 122 (2007).
41) “Problematics of Making Ambiguity Explicit in Virtual Reconstructions:
A Case Study of the Mausoleum of Augustus,” for the proceedings of an international
conference, “Computer Technology and the Arts: Theory and Practice,” sponsored by
the British Academy and the University of London.
42) “A Winged Goat Table Leg Support from the House of Numerius Popidius Priscus at
Pompeii,” in Pompei, Regio VII, Insula 2, pars occidentalis. Indagini, Studi,
Materiali (la Soprintendenza Archeologica di Pompei), ed. L. Pedroni.
43) “Augustus: Portraits of Augustus,” in Oxford Encyclopedia of Ancient Greece and
Rome (2008).
44) “A New Bronze Lar and the Role of the Lares in the Domestic and Civic Religion of the Romans,” in Latomus (2008).
IN PROGRESS:
45) “The ‘Colville Athena’ Head and Its Typology.”
46) “Idealplastik and Idealtheorie: Paradeigmatic Systems, Homosexual Desire, and the
Rhetoric of Identity in Polykleitos’ Doryphoros and Diadoumenos.”
REVIEW ARTICLES
PUBLISHED:
D. Boschung, Die Bildnisse des Augustus (Das römische Herrscherbild I.2) (Berlin 1993),
in Art Bulletin 81 (1999) 723-35.
E. Varner, Mutilation and Transformation: Damnatio Memoriae and Roman Imperial
Portraiture (Monumenta Graeca et Romana 10) (Leiden 2004), in Art Bulletin 88
(2006) 591-98.
BOOK REVIEWS
PUBLISHED:
M. Torelli, Typology and Structure of Roman Historical Reliefs, in American Journal of
Archaeology 87 (1983) 572-73.
J. Ganzert, Das Kenotaph für Gaius Caesar in Limyra, in American Journal of
Archaeology 90 (1986) 134-36.
R. Brilliant, Visual Narratives. Storytelling in Etruscan and Roman Art in American
Journal of Philology 107 (1986) 523-27.
PUBLISHED IN CHOICE:
E. Bartman, Portraits of Livia: Imaging the Imperial Woman in Augustan Rome, in
vol. 37 (1999) 126.
B.S. Ridgway, Prayers in Stone: Greek Architectural Sculpture (Ca. 600 - 100 B.C.),
in vol. 37 (2000) 1095.
W.E. Mierse, Temples and Towns in Roman Iberia: The Social and Architectural
Dynamics of Sanctuary Designs from the Third Century B.C. to the Third Century A.D.
in vol. 37 (2000) 1458.
V. Karageorgis, Ancient Art from Cyprus: The Cesnola Collection in The Metropolitan
Museum of Art (New York 2000)in vol. 38 (2000) 1953.
Z. Hawass, Valley of the Golden Mummies (New York 2000) in vol. 38 (2001)
4036.
M.W. Jones, Principles of Roman Architecture (New Haven 2000) in vol. 38 (2001)
5409.
F. Salmon, Building on Ruins: The Rediscovery of Rome and English Architecture
(Ashgate 2000) in vol. 39 (2001) 106.
J. Boardman, The History of Greek Vases: Potters, Painters and Pictures (New York
2001) in vol. 39 (2002) 3755.
Roman Sculpture in the Art Museum, Princeton University, ed. J. M. Padgett (Princeton
2001) in vol. 39 (2002) 6218.
G. Hedreen, Capturing Troy: The Narrative Function of Landscape in Archaic and Early
Classical Greek Art (Ann Arbor, 2001) in vol. 40 (2002) 73.
A. J. Clark, M. Elston, and M.L. Hart, Understanding Greek Vases: A Guide to Terms,
Styles, and Techniques (Los Angeles 2002) in vol. 40 (2003) 3185.
S. Woodford, Images of Myths in Classical Antiquity (Cambridge 2003) in vol. 41
(2003) 89.
J. Aruz with R. Wallenfels (edd.), Art of the First Cities: The Third Millennium B.C. from
the Mediterranean to the Indus (The Metropolitan Museum of Art, New York) (New
Haven 2003) in vol. 41 (2004) 2584.
G. Curtis, Disarmed: The Story of the Venus de Milo (New York 2003) in vol. 41 (2004)
5083.
Games for the Gods: The Greek Athlete and the Olympic Spirit, edd. J.J. Herrmann and C.
Kondoleon (Boston Museum of Fine Arts) in vol. 42 (2004) 646.
E.W. Leach, The Social Life of Painting in Ancient Rome and on the Bay of Naples
(Cambridge 2004) in vol. 42 (2004) 1215-16.
D. Mazzoleni, Domus: Wall Painting in the Roman House (Los Angeles 2004) in vol. 42
(2005) 1809.
S. Fine, Art and Judaism in the Greco-Roman World: Toward a New Jewish Archaeology
(Cambridge 2005) in vol. 43 (2006) 1586-87.
C.H. Hallett, The Roman Nude: Heroic Portrait Statuary 200 B.C. -- A.D. 300 (Oxford
2005) in vol. 44 (2006).
Constantine the Great: York’s Roman Emperor, edd. E. Hartley, J. Hawkes, M. Henig, and
F. Mee (York 2006) in vol. 44 (2006).
M.D. Stansbury-O’Donnell, Vase Painting, Gender, and Social Identity in Archaic Athens
(Cambridge 2006) in vol. 44 (2006).
PRINCIPAL INSTRUCTIONAL MATERIALS (Hard Copy and Online):
Greek Art and Archaeology: Course Manual (113 pages, 23 plates) and online version of
this Course Manual with digitized images
Roman Art and Archaeology: Course Manual (158 pages, 58 plates) and online version
of this Course Manual with digitized images
Digging into the Past: Material Culture and the Civilizations of the Ancient
Mediterranean: Course Manual (43 pages)
Proseminar Guide to General and Specific Works on Greek and Roman Art and
Archaeology and Related Disciplines (50 pages) and online version
Website for AHIS 425, “Introduction to Interdisciplinary Research and Methodology
in Classical Art and Archaeology and Related Disciplines” with links to other important
websites in the fields of Art, Archaeology, Classics, and Ancient History
Website for AHIS 201g: “Digging into the Past: Material Culture and the
Civilizations of the Ancient Mediterranean” (with digitized images)
PAPERS GIVEN AT INTERNATIONAL AND NATIONAL
CONFERENCES AND SYMPOSIA
On Judging the Merits of Augustus: Center for Hermeneutical Studies: Colloquy,
Berkeley (April, 1985)
Investigating Hellenistic Sculpture: Center for Advanced Study in the Visual Arts,
National Gallery of Art (October, 1986)
Augustus: Monuments, Arts, and Religion: Brown University (March, 1987)
Aspects of Ancient Religion: University of California at Berkeley (April, 1987)
Marble and Ancient Greece and Rome: International conference sponsored by
NATO at Il Ciocco (Tuscany), Italy (May, 1988)
Polykleitos, the Doryphoros and Its Influence: University of Wisconsin, Madison
(October, 1989)
UCLA-USC Seminar in Roman Studies: UCLA, Los Angeles (December, 1992)
XIIIth International Bronze Congress: Harvard University (May 28 - June 1, 1996)
UCLA-USC Seminar in Roman Studies: Roman Representations: Subjectivity, Power
and Space: USC, Los Angeles (March, 1997)
International Symposium at Cuma (Naples): Flavian Poets, Artists, Architects and
Engineers in the Campi Flegrei (July, 1997)
International Symposium at the University of Vienna: Interdisziplinäres Kolloquium
Historische Architekturreliefs vom Alten Ägypten bis zum Mittelalter (July, 1997)
First International Conference on the Archaeology of Paros and the Cyclades: Paros,
Greece (October, 1997)
Getty Research Institute Colloquium: Work in Progress (November, 1997)
Annual Meetings of the Art Historians of Southern California at California State
University, Northridge, California (November, 1998)
XIV. Internationaler Kongress für Antike Bronzen: Werkstattkreise, Figuren und Geräte
(Sponsored by Das Römisch-Germanisches Museum der Stadt Köln und das
Archäologisches Institut der Universität zu Köln [September 1999]): Besides giving paper,
chaired the session “Bronzestatuen und -statuetten: Fundkomplexen, Fundgruppen,
Einzelstücke, und Typen”
First International Symposium on Roman Imperial Ideology: Politics, Art, and
Numismatics at the Villa Vergiliana, Cuma (Naples) -- keynote speaker and chaired
session on “Ideology, Historiography, and the Imperial Family” (May, 2000)
International Symposium at Emory University, Atlanta: Tyranny and Transformation
(October, 2000)
Annual Meeting of the Art Historians of Southern California at the Getty Center,
Los Angeles, California (November, 2000)
Getty Research Institute Colloquium: Work in Progress (December, 2000)
Second International Symposium on Roman Imperial Ideology: Politics, Art, and
Numismatics at the Villa Vergiliana, Cuma (Naples) -- chaired session on “The Image of
the Princeps and the Ruler Cult” (May, 2001)
UCLA-USC Seminar in Roman Studies: UCLA, Los Angeles (April, 2002)
Third International Symposium on Roman Imperial Ideology: Politics, Art, and
Numismatics at the Villa Vergiliana, Cuma (Naples) -- chaired session on “Roman History
and Ideology” (May, 2002)
Symposium on the Age of Augustus at UCLA -- (Feb., 2003)
Fourth International Symposium on Roman Imperial Ideology: Politics, Art, and
Numismatics at the Villa Vergiliana, Cuma (Naples) -- keynote speaker and
chaired session (May, 2003)
International Archaeological Congress, Harvard University (Aug. 2003): Besides giving a
paper, chaired session on “Ancient Society”
VIIth International ASMOSIA Conference, Thasos, Greece (Sept. 2003)
International Conference in the Arts and the Humanities, Honolulu, Hawaii (Jan. 2004)
Symposium on Roman Sculpture, Minneapolis Museum of Art (organized by Richard
Brilliant) (April, 2004)
International Symposium on Interaction of Indigenous and Foreign Cults in Italy at Cuma
(Naples) (May, 2004): Besides giving a paper, chaired session
International Conference at University of Michigan: “‘Sculptural Environment’ of the
Roman Near East: Reflections on Culture, Ideology, and Power (November 2004)
International Conference at Stanford University: “Seeing the Past” (February 2005)
International Conference at the University of London: “Computer Technology and the Arts:
Theory and Practice” (November 2005)
International Conference at the University of Chicago: “Performing Death: Social Analyses
of Funerary Ritual in the Mediterranean” (February 2006)
VIIIth International ASMOSIA Conference, Aix-en-Provence, France (June 2006)
Symposium “Art of Warfare”: Michael C. Carlos Museum, Emory University (January
2007)
PAPERS PRESENTED AT ANNUAL CONVENTIONS OF THE
ARCHAEOLOGICAL INSTITUTE OF ARCHAEOLOGY AND THE
COLLEGE ART ASSOCIATION
Boston (AIA, December, 1979)
New Orleans (AIA, December, 1980)
San Francisco (AIA, December, 1981)
Philadelphia (AIA, December, 1982)
Cincinnati (AIA, December, 1983)
Toronto (AIA, December, 1984)
Washington, D.C. (AIA, December, 1985) -- invited paper, “The Promulgation of the
Image of the Leader in Roman Art,” in a special AIA plenary session on Politics and
Art
San Antonio (AIA, December, 1986) -- invited paper, “Time, Narrativity, and Dynastic
Constructs in Augustan Art and Thought,” at a joint AIA-APA session on topics
illustrating connections between Roman art and philology
Houston (CAA, February, 1988) -- invited paper, “The Gemma Augustea and the
Construction of a Dynastic Narrative,” for a CAA session on Narrative and Event in
Greek and Roman Art
Atlanta (AIA, December, 1994) -- discussant for a joint AIA-APA session on “Rethinking
Nero’s Legacy: New Perspectives on Neronian Art, Literature, and History”
New York (AIA, December, 1996) -- special poster session: “The Marble Type of the
Statue of Augustus from Prima Porta: New Scientific Tests” (prepared in collaboration
with Norman Herz, Director of Programs, Center for Archaeological Sciences, University
of Georgia)
Chicago (AIA, December, 1997)
Washington, D.C. (AIA, December, 1998) -- invited paper, “A Portrait of a Sex-Slave
‘Stud’ (?) in the Metropolitan Museum of Art in New York,” for a special colloquium in
honor of Anna Marguerite McCann on the receipt of the “Gold Medal” of the
Archaeological Institute of America
San Francisco (AIA, January, 2004) -- joint paper with N.Cipolla and L. Swartz Dodd
OTHER ACADEMIC AND PUBLIC LECTURES/TALKS
American Academy, Rome, Italy (March, 1976)
Cleveland Society AIA, Cleveland, Ohio (April, 1979)
Johns Hopkins University, Baltimore, Md. (September, 1980)
Institute of Fine Arts, New York, N.Y. (October, 1980)
Metropolitan Museum of Art, New York, N.Y. (January, 1983)
New York Society AIA, New York, N.Y. (January, 1983)
Baltimore Society AIA, Baltimore, Md. (February, 1983)
University of Toronto, Toronto, Canada (March, 1987)
University of Southern California, Los Angeles, Ca. (March, 1987)
Columbia University, New York, N.Y. (April, 1987)
Classical Archaeological Society of Southern California, UCLA, Ca. (November 1989)
Tulane University, New Orleans, La. (February, 1990)
Classical Archaeological Society of Southern California, USC, Ca. (February 1990)
Los Angeles Society AIA, Los Angeles, Ca. (March, 1990)
Fisher Gallery and School of Fine Arts, University of Southern California, Los Angeles,
Ca. (March, 1990)
Institute of Fine Arts, New York, N.Y. (April, 1990)
American Academy, Rome, Italy (May, 1990)
University of Vienna and Kunsthistorisches Museum, Vienna, Austria (June, 1990)
San Diego Society AIA, San Diego, Ca. (September, 1990)
Classical Archaeological Society of Southern California, Getty Museum, Malibu, Ca.
(November, 1990).
University of Pennsylvania, Philadelphia, Pa. (December, 1990)
Classical Archaeological Society of Southern California, Gamble House, Pasadena, Ca.
(March 1991)
Henry T. Rowell Lecturer: Baltimore Society AIA, Baltimore, Md. (November, 1991)
Villanova University, Villanova, Pa. (November, 1991)
Royal-Athena Galleries, Los Angeles, Ca. (October, 1992)
Center for Advanced Study in the Visual Arts (CASVA), National Gallery of Art,
Washington D.C. (November, 1992)
University of North Carolina, Chapel Hill, N.C. (November, 1992)
Duke University, Durham, N.C. (November, 1992)
University of California, Los Angeles: UCLA/USC Seminar in Roman Studies, Los
Angeles, Ca. (December, 1992)
University of Southern California, Los Angeles, Ca. (January, 1993)
J. Paul Getty Museum and Center for the History of Art and the Humanities, Malibu,
Ca. (February, 1993)
Classical Archaeological Society of Southern California, UCLA, Ca. (March 1993)
California State University, Long Beach, Ca. (March, 1993)
Stanford University, Palo Alto, Ca. (April, 1993)
University of California, Berkeley, Ca. (April, 1993)
California State University, Northridge, Ca. (April, 1993)
University of Arizona, Tucson, Az. (April, 1993)
American Academy, Rome, Italy (June, 1994)
Getty Center for the History of Art and the Humanities (Director’s Series) (Dec., 1994)
University of California, Irvine (May, 1997)
American Academy, Rome, Italy (July, 1997)
American School of Classical Studies, Athens (October, 1997)
Los Angeles County Museum of Art, Los Angeles (March, 1998)
British School at Rome (June, 1998)
University of California, Berkeley (November, 1998)
Classical Archaeological Society of Southern California, University of California,
Santa Barbara (March, 1999)
Work in Progress: Getty Research Institute, Brentwood, California (December, 2000)
Classical Archaeological Society of Southern California, Getty Research Institute,
Brentwood, Ca. (April, 2001)
American Academy, Rome, Italy (May, 2001)
Loyola Marymount, Los Angeles (March, 2002)
Southern California Institute of Architecture (February, 2003)
Columbia University, New York (April, 2003)
University of Amsterdam, the Netherlands (May, 2003)
University of Nijmegen, the Netherlands (May, 2003)
American School of Classical Studies, Athens (September, 2003)
University of Oklahoma, Norman (March, 2005)
Cambridge University, Cambridge, England (November, 2005)
American School of Classical Studies at Athens, Greece (March, 2007)
University of Athens, Greece (May, 2007)
Los Angeles Society of the AIA, Los Angeles (December, 2007)
College of William and Mary (January, 2008)
Duke University, Durham (February, 2008)
Dickinson College, Carlisle, PA (March, 2008)
University of Nebraska, Lincoln (April, 2008)
AMERICAN SCHOOL OF CLASSICAL STUDIES AT ATHENS as Whitehead Professor of Archaeology (2006-2007)
Participated in all Fall trips of the School to various parts of Greece, giving
presentations on each of the trips.
Participated in the School’s Spring trip to Central Anatolia, giving several presentations.
Offered a seminar in the Winter Quarter: “Christian Destruction and Desecration of
Images and Shrines of Classical Antiquity.”
MISCELLANEOUS TALKS AND PRESENTATIONS
Lectures and talks on site regarding the architecture and topography of Rome, Ostia,
and Hadrian’s Villa for members of the Technische Universität für Architektur und
Denkmalpflege, Vienna, Austria; the Summer School of the American Academy in
Rome; St. Olaf College’s Junior Year Abroad Program; and M.A. students of
architecture in a joint summer program of the University of Southern California and the
University of Illinois; and the Intercollegiate Center for Classical Studies in Rome.
Talks on various aspects of Classical art and archaeology at meetings of the
Archaeological Society of the Mid-Atlantic States (1980-1987)
Gallery talks on the ancient collections of the Archaeological Museum of the Johns
Hopkins University (in capacity as curator) and of the Walters Art Gallery (1979-1987)
Gallery talks on the ancient collections of the J. Paul Getty Museum and the Los Angeles
County Museum of Art (1987-present)
Talk for USC graduate students in the Dept. of Classics at the Ara Pacis and Mausoleum of
Augustus in Rome (May 26, 2006), organized by Prof. Claudia Moatti, Dept. of Classics
SPECIAL TALKS AND LECTURES AT USC
Seminar for Professor Claudia Moatti, Department of Classics: “Problems in Ancient Art”
(March, 2005)
Seminar for Dr. Daniela Bleichmar, Department of Art History: Rediscovering the
Classical Past: The Relationship of Art History, Archaeology, and Visual Culture (March,
2005)
University of Southern California’s 125th Celebration: For Symposium on “Trojan
Legends” presented paper: “USC's Trojan Column: An Ancient and Modern Myth”
(October, 2005)
MEDIA INTERVIEWS AND CONSULTATION
New York Times, International Herald Tribune, Los Angeles Times, The New Yorker, The
History Channel, Arts and Entertainment Channel, KPCC Radio Los Angeles, NBC, Fox
Featured piece on my innovative work on the marble type of the statue of Augustus from
Prima Porta: A. Elders, “Tracing the Stones of Classical Brilliance,” in Hermes -- Greece
Today 35 (1999) 20-24.
ORGANIZER AND LEADER OF TOURS OF MUSEUMS AND SITES
Turkey (for Board of Councilors and donors of the School of Fine Arts, USC, 1995; for
university students and the general public, 1998)
Greece (Attica and the Peloponnese) (for university students and the general public, 1999)
Central Italy (for university students and the general public, 2000, 2002, 2003)
PARTICIPATION IN OTHER COLLOQUIA AND SYMPOSIA
Roman Sculpture and Architecture: German Archaeological Institute, Rome
(January, 1978)
Roman Architecture: Center for Advanced Study in the Visual Arts, National Gallery
of Art (January, 1981)
The Age of Augustus. The Rise of Imperial Ideology: Brown University (April, 1982)
Pictorial Narratives in Antiquity and the Middle Ages: The Johns Hopkins University and
the Center for Advanced Study in the Visual Arts, National Gallery of Art (March, 1984)
Villa Gardens of the Roman Empire: Dumbarton Oaks (May, 1984)
Retaining the Original -- Multiple Originals, Copies, and Reproductions: Center for
Advanced Study in the Visual Arts, National Gallery of Art (March, 1985)
Investigating Hellenistic Sculpture: Center for Advanced Study in the Visual Arts,
National Gallery of Art (October, 1986)
Marble -- Art Historical and Sculptural Perspectives on Ancient Sculpture: J. Paul Getty
Museum (April, 1988)
International Conference on Roman Archaeology and Latin Epigraphy: University of
Rome and the French School of Rome (May, 1988)
Roman Portraits in Context: Emory University (January, 1989)
Small Bronze Sculpture from the Ancient World: J. Paul Getty Museum (March, 1989)
Alexandria and Alexandrianism: J. Paul Getty Museum (April, 1993)
International Symposium: “Rome Reborn” Visual Reality Program at UCLA (December,
1996)
History of Restoration of Ancient Stone Sculptures, J. Paul Getty Museum (October, 2001)
Re-Restoring Ancient Stone Sculpture, J. Paul Getty Museum (March, 2003)
Marble Conference on Thasos, Liman, Thasos (Sept. 2003)
OTHER PROFESSIONAL ACTIVITIES
Editorial Assistant (1968-1969) and Associate Editor (1969-1970), AGON: Journal of
Classical Studies
Editorial Board, American Journal of Philology (January, 1982-January, 1987)
Delegate from Baltimore Society AIA to National Convention (1984-1986)
Vice-President, Baltimore Society of the AIA (1985-1987)
Co-Director, Exhibition on Roman Portraiture, Fisher Gallery (1989)
Co-Founder (with Dr. Diana Buitron) of the Classical Archaeological Society of the Mid-
Atlantic States (1978-87)
Founder and President of the Classical Archaeological Society of Southern California
(1987-present)
Member of the Ancient Art Council of the Los Angeles County Museum of Art (1987-
present)
Oversaw the publication and helped edit the newsletter “ARTFACTS” of the
School of Fine Arts (1993-1996) during my tenure as Dean of the School of Fine Arts
USC Representative to Advisory Council of the American Academy in Rome
(1993-present)
Comitato di Collaborazione Culturale to the Consul General of Italy at Los Angeles
(1995-1998)
Advisory Committee for the Virtual Reality Project for Ancient Rome (“Rome Reborn”)
(1996-1998)
Delegate from Los Angeles Society AIA to National Convention (Chicago, Dec., 1997)
Reviewer for the Getty Grant Program (1999)
Reviewer for the MacArthur Foundation Grant (2000, 2003)
Planning Committee for a Four-Year International Conference on “Roman Imperial
Ideology” at the Villa Vergiliana at Cuma (Naples), organized by J. Rufus Fears (2000-
2003)
Consultant for the Forum of Augustus Project: Sovrintendenza Archeologica Comunale,
Direzione al Foro di Augusto (2004-present)
Editor of the newsletter “Musings” for the Department of Art History, USC (2005)
Planning Committee for the Internation Bronze Congress in Athens, Greece (2006-2007)
Chaired two sessions -- “Roman Sculpture” and “Augustan Art” -- at the Annual Meeting
of the Archaeological Institute of America (San Diego 2007)
UNIVERSITY COMMITTEES AND OTHER SERVICE
Faculty Senate (1988-1991)
Advisory Committee to the Dean of the School of Fine Arts (1990-1991, 1992-1993)
Chairman, Personnel Committee of the School of Fine Arts (1988-1990)
Library Liaison Officer for Art and Architecture Library (1987-present)
Search Committee for Reference Librarian of the Art and Architecture Library
(1989-1990 and 2000)
University Library Committee (1989-1990, 1998-2001)
Recruitment Committee for the School of Fine Arts (1989-1995)
Space Allocation Committee, School of Fine Arts (1989-1990)
University Research Committee (1990-1991)
Promotion Committee, School of Fine Arts (1990-1995)
University Ad Hoc Committee on Revenue Center Management (1990-1995)
Committee for University Development, School of Fine Arts (1993-1995)
Development Task Force, the School of Fine Arts (1993-1995)
Consultative Committee to the Provost (Spring 1993-1995)
University Galleries Advisory Committee (1993-1995)
University Committee on Transnational and Multicultural Affairs (1993-1995)
Provost’s Council at USC (formerly Council of Deans) (1993-1995)
USC Representative to the Advisory Council of the American Academy in Rome
(1993-present)
Founder and Member of the Board of Councilors for the School of Fine Arts (1994-1995)
Consortium Council of Deans for Development at USC (1995)
Tenure and Promotion Committee, Department of Art History (1995-to present)
Recruitment Committee for Department of Art History in the College of
Letters, Arts, and Sciences (1996-2005)
Program Proposer for the Establishment of an Interdepartmental and Interdisciplinary
Ancient Mediterranean Studies Program (1997-1999)
Chinese Search Committee, Department of Art History (1998-1999)
Japanese Search Committee, Department of Art History (1998-1999)
Professor-In-Charge, USC-Getty Lecture Series, Seminar, and Faculty Dinner (honoring
Salvatore Settis) (1998-1999)
Curriculum Committee (Co-Chair) (1998-1999)
Chair, Committee for Selection of Departmental Chair (1999-2000)
Chair, Merit Review Committee (1999-2000)
Committee for the Establishment of an Undergraduate Major in Archaeology
(2002-present)
Greek Art Search Committee, Department of Art History and Classics (2001-2004)
Faculty Search Committee, Department of Art History: Senior Hiring Initiative (2003-
present)
Junior Faculty Review Committee, Department of Art History (2003)
USC’s Arts and Humanities Committee (2003-2004)
Chair of Oversight Committee for the Interdisciplinary Archaeology Major (Spring 2006)
MEMBERSHIPS IN NATIONAL AND INTERNATIONAL PROFESSIONAL ORGANIZATIONS
NATIONAL:
Archaeological Institute of America
College Art Association
American Philological Association
Association of Ancient Historians
Vergilian Society
INTERNATIONAL:
Deutsches Archäologisches Institut
Associazione Internazionale di Archeologia Classica
Association for the Study of Marble and Other Stones in Antiquity (AMOSIA)
Society for the Promotion of Roman Studies
If you are interested in Julio Claudian Iconography and portrait study you may enjoy these two links:
Julio Claudian Iconographic Association- Joe Geranio- Administrator at groups.yahoo.com/group/julioclaudian/
The Portraiture of Caligula- Joe Geranio- Administrator- at
Both are non-profit sites and for educational use only.
The "Salinelle dello Stadio" of Paternò are active mud volcanoes at the south base of Etna, whose activity is in direct correlation with the volcano Etna itself. They are a phenomenon of secondary volcanism.
More info at wwwold.comune.paterno.ct.it/ambiente/salinelle.htm
The "Salinelle dello Stadio" of Paternò are active mud volcanoes at the south base of Etna, whose activity is in direct correlation with the volcano Etna itself. They are a phenomenon of secondary volcanism.
More info at wwwold.comune.paterno.ct.it/ambiente/salinelle.htm
Spacecraft: NASA MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging)
©NASA/JHUAPL/CIW/AndreaLuck
Raw Data processed from: pds-imaging.jpl.nasa.gov/
Time: 2008-10-06 10:10
Altitude 27335 km
PRODUCT IDs: CW0131775244I_RA_5, CW0131775252G_RA_5, CW0131775256F_RA_5
FILTERS: 1000nm BW 15(Used for Red Channel), 750nm BW 5 (Used for Green Channel), 430nm BW 40 (Used for Blue Channel)
©NASA/JHUAPL/CIW/AndreaLuck
Feel free to share, giving the appropriate credit and providing a link to the original image or tweet creativecommons.org/licenses/by/3.0/
Twitter: twitter.com/andrluck/status/1594351552357355525?s=46&...
Mineral-rich deposits out of numerous vents in the area of the "Salinelle", the mud volcanoes near the town of Paternò at the south base of Etna.
This is a sample of metamorphosed mantle rock. Such rocks don't often get uplifted to Earth's surface. Exceptions include ophiolites and mantle xenoliths in some lava flows. Ophiolites are fragments of oceanic lithosphere (basaltic crust + uppermost mantle) that have been metamorphosed and plastered onto the edges of continental lithospheric plates by obduction (the opposite of subduction).
In this rock, the pale green is serpentine, a magnesium hydroxy-silicate mineral (Mg3Si2O5(OH)4) formed by metamorphic alteration of olivine in the presence of water. The black is chromite, an iron chromium oxide mineral (FeCr2O4). Before metamorphism, the material was an olivine-chromite, ultramafic, intrusive igneous rock. Perhaps "chromitic dunite" can describe the original rock.
The sample comes from the Bulqiza Ophiolite in Albania. Especially chromite-rich rocks in the ophiolite complex are mined for the chromium content. The basal sedimentary rocks in the ophiolite stratigraphic section are Middle Jurassic radiolarian cherts.
Geologic unit: Bulqiza Complex (Bulqiza Ophiolite / Bulqiza Massif / Bulqizë Massif / Bulqiza Zone), Eastern Mirdita Ophiolite
Locality: Batra Mine (Bater Mines), Dibër County, Albania
----------------------------------
Info. at:
Xiong et al. (2015) - Petrology and geochemistry of high Cr# podiform chromitites of Bulqiza, Eastern Mirdita Ophiolite (EMO), Albania. Ore Geology Reviews 70: 188-207.
Photographed from our running bus.
My first experience about YNP
We entered Yellowstone NP through the eastern entrance using U.S. Route 14. It had been a moderate snow fall in the end of the first week of October, 2017. From few kilometers before reaching Yellowstone Lake, remnants of devastating wild fire were being evident. It was a shocking sight for me at the beginning and could not perceive how fire had devastated hundreds of acres of alpine forests in the valleys and atop the hills. But when I had a closer look to the floor of the forests, I was amazed by the facts how nature maintains its ecological balance! Numerous tiny siblings are growing besides the burnt and decaying logs. The future forests of the park are coming alive.
The park seemed to me the world’s finest natural laboratory and archive to study and understand all the faculties of human intellect.
The qualities of the photographs are not satisfactory, because they were taken so fast through the glass windows of our running bus. But I didn’t want to miss such life time opportunities. The overall beauties were essentially more important than technicalities, as I always believe.
Our luck didn’t favor anyway in this park trip, when our tour guide had declared a forecast for heavy snowfall next day since morning. He therefore decided to visit as many spots as possible in a single day, and not to wait for day-2. I hurried through the trails taking as many snaps as possible.
The next day heavy snowfall started since 9 am, and our guide cancelled the day-2 trip. Thanks God…we covered somehow all the spots on the first day.
I hope, you may like my Yellowstone series…
A quick overview of YNP
Yellowstone National Park is an American national park located in Wyoming, Montana, and Idaho. Approximately 96 percent of the land area of Yellowstone National Park is located within the state of Wyoming. The Park spans an area of 8,983 km2 comprising lakes, canyons, rivers and mountain ranges. The park is known for its wildlife and its many geothermal features. It has many types of ecosystems, but the subalpine forest is the most abundant. It is part of the South Central Rockies forests eco-region.
It was established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the U.S. and is also widely held to be the first national park in the world. Native Americans have lived in the Yellowstone region for at least 11,000 years. Aside from visits by mountain -men during the early to mid-19th century, organized exploration did not begin until the late 1860s.
The park contains the headwaters of the Yellowstone River, from which it takes its historical name. Although it is commonly believed that the river was named for the yellow rocks seen in the ‘Grand Canyon of the Yellowstone’, the Native American name source is unclear.
Yellowstone Lake is one of the largest high-elevation lakes in North America and is centered over the Yellowstone Caldera, the largest supervolcano on the continent. The caldera is considered as an active volcano. It has erupted with tremendous force several times in the last two million year. The Yellowstone Caldera is the largest volcanic system in North America. It has been termed a "supervolcano" because the caldera was formed by exceptionally large explosive eruptions. The magma chamber that lies under Yellowstone is estimated to be a single connected chamber, about 60 km long, 29 km wide, and 5 to 12 km deep. Yellowstone Lake is up to 400 feet deep and has 180 km of shoreline.The lake is at an elevation of 7,733 feet above sea levels. Half of the world's geysers and hydrothermal features are there in Yellowstone, fueled by this ongoing volcanism. Lava and rocks from volcanic eruptions cover most of the land area of Yellowstone. The park is the centerpiece of the Greater Yellowstone Ecosystem, the largest remaining nearly-intact ecosystem in the Earth's northern temperate zone. In 1978, Yellowstone was named a UNESCO World Heritage Site.
In May 2001, the U.S. Geological Survey, Yellowstone National Park, and the University of Utah created the Yellowstone Volcano Observatory (YVO), a partnership for long-term monitoring of the geological processes of the Yellowstone Plateau volcanic field, for disseminating information concerning the potential hazards of this geologically active region.
Hundreds of species of mammals, birds, fish, and reptiles have been documented, including several that are either endangered or threatened. The vast forests and grasslands also include unique species of plants. Yellowstone Park is the largest and most famous mega fauna location in the contiguous United States. Grizzly bears, wolves, and free-ranging herds of bison and elk live in this park. The Yellowstone Park bison herd is the oldest and largest public bison herd in the United States.
Forest fires occur in the park each year. In the largest forest fires of 1988, nearly one third of the park was burnt.
Yellowstone has numerous recreational opportunities, including hiking, camping, boating, fishing and sightseeing. Paved roads provide close access to the major geothermal areas as well as some of the lakes and waterfalls. During the winter, visitors often access the park by way of guided tours that use either snow coaches or snowmobiles.
Fire in Yellowstone NP:
Causes of wildfire in Yellowstone NP
Wildfire has had a role in the dynamics of Yellowstone’s ecosystems for thousands of years. Although many fires were caused by human activities, most ignitions were natural. The term "natural ignition" usually refers to a lightning strike. Afternoon thunderstorms occur frequently in the northern Rocky Mountains but release little precipitation, a condition known as ‘dry lightning’. In a typical season there are thousands of lightning strikes in Yellowstone. Lightning strikes are powerful enough to rip strips of bark off of a tree in a shower of sparks and blow the pieces up to 100 feet away. However, most lightning strikes do not result in a wildfire because fuels are not in a combustible state.
The great fire incidence of 1988
The Yellowstone fires of 1988 collectively formed the largest wildfire in the recorded history of Yellowstone National Park in the United States. Starting as many smaller individual fires, the flames quickly spread out of control due to drought conditions and increasing winds, combining into one large conflagration which burned for several months. The fires almost destroyed two major visitor destinations and, on September 8, 1988, the entire park closed to all non-emergency personnel for the first time in its history. Only the arrival of cool and moist weather in the late autumn brought the fires to an end. A total of 793,880 acres, or 36 percent of the park was affected by the wildfires.
Fire incidence, 2016
As of September 21, 2016, 22 fires (human and lightning-caused) have burned more than 62,000 acres in Yellowstone National Park, making it the highest number of acres burned since the historic 1988 fire.
Heritage and Research Center
The Heritage and Research Center is located at Gardiner, Montana, near the north entrance to the park. The center is home to the Yellowstone National Park's museum collection, archives, research library, historian, archeology lab, and herbarium. The Yellowstone National Park Archives maintain collections of historical records of Yellowstone and the National Park Service. The collection includes the administrative records of Yellowstone, as well as resource management records, records from major projects, and donated manuscripts and personal papers. The archives are affiliated with the National Archives and Records Administration.
Geothermal features of Yellowstone NP- A brief note:
There are four geothermal features found in the park – Hot springs, Geysers, Fumaroles , and Mud volcanoes/pots.
What is a Hot spring?
Hot spring, also called thermal spring, spring with water at temperatures substantially higher than the air temperature of the surrounding region. Most hot springs discharge groundwater that is heated by shallow intrusions of magma (molten rock) in volcanic areas.
Some thermal springs, however, are not related to volcanic activity. In general, the temperature of rocks within the earth increases with depth. The rate of temperature increase with depth is known as the geothermal gradient. In such cases, the water is heated by convective circulation: groundwater percolating downward reaches depths of a kilometre or more where the temperature of rocks is high because of the normal temperature gradient of the Earth’s crust—about 30 °C / kilometer in the first 10 km. The water from hot springs in non-volcanic areas is heated in this manner.
But in active volcanic zones such as Yellowstone National Park, water may be heated by coming into contact with magma (molten rock). The high temperature gradient near magma may cause water to be heated enough that it boils or becomes superheated. If the water becomes so hot that it builds steam pressure and erupts in a jet above the surface of the Earth, it is called a geyser.
[ Warm springs are sometimes the result of hot and cold springs mixing. They may occur within a volcanic area or outside of one. One example of a non-volcanic warm spring is Warm Springs, Georgia (frequented for its therapeutic effects by paraplegic U.S. President Franklin D. Roosevelt, who built the Little White House there) ].
List of hot springs:
[ en.wikipedia.org/wiki/List_of_hot_springs ]
The science of colors of a hot spring:
[ ttps://www.britannica.com/science/hot-spring]
Many of the colours in hot springs are caused by thermophilic (heat-loving) microorganisms, which include certain types of bacteria, such as cyanobacteria, and species of archaea and algae. Many thermophilic organisms grow in huge colonies called mats that form the colourful scums and slimes on the sides of hot springs. The microorganisms that grow in hot springs derive their energy from various chemicals and metals; potential energy sources include molecular hydrogen, dissolved sulfides, methane, iron, ammonia, and arsenic. In addition to geochemistry, the temperature and pH of hot springs play a central role in determining which organisms inhabit them.
Examples of thermophilic microorganisms found in hot springs include bacteria in the genera Sulfolobus, which can grow at temperatures of up to 90 °C (194 °F), Hydrogenobacter, which grow optimally at temperatures of 85 °C (185 °F), and Thermocrinis, which grow optimally at temperatures of 80 °C (176 °F). Thermophilic algae in hot springs are most abundant at temperatures of 55 °C (131 °F) or below.
What is a Geyser?
A geyser is formed when water collecting below the surface is heated by a magma source. When the water boils, it rises to the surface. If the water has an unobstructed path, it will pool on the surface in the form of a steaming hot springs. If the passage of the water is imposed upon, the pressure will increase. When the pressure becomes too great, the water converts into to steam. Steam takes up 1,500 times the volume of water, and at this point, the pressure becomes so intense that the steam and surrounding water droplets shoot out of the ground in geyser form, erupting until the pressure has abated and the process starts all over again.
What is a fumarole?
It’s a vent in the Earth’s surface from which steam and volcanic gases are emitted. The major source of the water vapour emitted by fumaroles is groundwater heated by bodies of magma lying relatively close to the surface. Carbon dioxide, sulfur dioxide, and hydrogen sulfide are usually emitted directly from the magma. Fumaroles are often present on active volcanoes during periods of relative quiet between eruptions.
Fumaroles are closely related to hot springs and geysers. In areas where the water table rises near the surface, fumaroles can become hot springs. A fumarole rich in sulfur gases is called a solfatara; a fumarole rich in carbon dioxide is called a mofette. If the hot water of a spring only reaches the surface in the form of steam, it is called a fumarole. [ www.britannica.com/science/fumarole ]
What is a mud volcano/ mud pot/ paint pot?-
Usually mud volcanoes are created by hot-spring activity where large amounts of gas and small amounts of water react chemically with the surrounding rocks and form a boiling mud.
Geo-chemistry of mud volcano: Hydrogen sulfide gas rising from magma chamber, as in Yellowstone’s, causes the rotten-egg smell. Microorganisms, or thermophiles, use this gas as a source of energy, and then help turn the gas into sulfuric acid. The acid then breaks down the rocks and soil into mud. Many of the colors seen are vast communities of thermophiles, but some of the yellow is pure sulfur. When iron mixes with sulfur to form iron sulfide, gray and black swirls sometimes appear in the mud (From description of the display board in the park).
If the water of a hot spring is mixed with mud and clay, it is called a mud pot. Variations are the porridge pot (a basin of boiling mud that erodes chunks of the surrounding rock) and the paint pot (a basin of boiling mud that is tinted yellow, green, or blue by minerals from the surrounding rocks).
There are other mud volcanoes, entirely of a nonigneous origin, occur only in oil-field regions that are relatively young and have soft, unconsolidated formations.
Sources: [ www.britannica.com/science/mud-volcano ], and display boards of the YNP.
A Quick Overview Map of Yellowstone
(www.yellowstonepark.com/park/overview-map-yellowstone)
Free Yellowstone Trip Planner:
( www.yellowstonepark.com/travel-guides/yellowstone-trip-pl...)
8 Best Yellowstone Geyser Basins and Map
( www.yellowstonepark.com/things-to-do/yellowstone-geyser-b... )
National Park Maps
( www.yellowstonepark.com/park/national-park-maps )
Interactive map of ALL Yellowstone thermal features at the Yellowstone Research Coordination Network
Two small fragments of Northwest Africa 7831 Diogenite meteorite. The larger fragment weighs 0.55 grams.
For scale, the black cube has sides of 1 cm.
Found: Saguia el Hamra, Western Sahara, March 2013.
[Latitude: 27.307°N, Longitude: 12.083°W].
Classification: Diogenite.
...................................
The Northwest Africa 7831 meteorite (NWA 7831) was found buried in the ground near Chouichiyat, Saguia el Hamra, Western Sahara in March 2013.
[Latitude: 27.307°N, Longitude: 12.083°W].
The single large mass (weighing at least 20 kg) was composed of yellow-green crystalline material with pale orange weathering products along numerous fractures. However, on excavation from the ground, much of the material disintegrated into fragments.
According to the Meteoritical Bulletin, NWA 7831 is composed almost entirely of translucent, yellow-green orthopyroxene with very sparse, tiny included grains of Ni-free metal, troilite, chromite, anorthite, silica polymorph and clinopyroxene. Secondary pale orange, clay-like deposits from terrestrial weathering are present along thin fractures.
The Meteoritical Bulletin gives the following geochemistry for NWA 7831:
Orthopyroxene (Fs 28.1 - 28.3 Wo 3.0 - 3.3; FeO/MnO = 29 - 31), clinopyroxene (Fs 10.9 Wo 43.1, FeO/MnO = 26).
NWA 7831 is classified as HED achondrite (Diogenite).
Shock stage: low
Weathering grade: moderate.
Diogenites are a type of achondrite (i.e. without chondrules) meteorite believed to originate from deep within the crust of an asteroid, most probably asteroid '4 Vesta'. As such they are part of the HED (howardite - Eucrite - diogenite) meteorite clan.
Diogenites are composed of igneous rocks that have slowly solidified deep within the asteroid's crust, forming crystals that are larger than in eucrites.
President Barack Obama delivers remarks at the National Medals of Science and National Medals of Technology and Innovation Awards Ceremony, Thursday, Nov. 20, 2014 in the East Room of the White House in Washington. MESSENGER Principal Investigator, director of Columbia University's Lamont-Doherty Earth Observatory, Sean Solomon, was awarded the National Medal of Science, the nation's top scientific honor, at the ceremony. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. Photo Credit: (NASA/Bill Ingalls)
President Barack Obama delivers remarks at the National Medals of Science and National Medals of Technology and Innovation Awards Ceremony, Thursday, Nov. 20, 2014 in the East Room of the White House in Washington. MESSENGER Principal Investigator, director of Columbia University's Lamont-Doherty Earth Observatory, Sean Solomon, was awarded the National Medal of Science, the nation's top scientific honor, at the ceremony. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. Photo Credit: (NASA/Bill Ingalls)
VENUS 2nd FLY BY
Spacecraft: NASA MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging)
©NASA/JHUAPL/CIW/AndreaLuck
Raw Data processed from: pds-imaging.jpl.nasa.gov/
Time: 2007-06-05 21:18
Altitude 60337 km
PRODUCT IDs: CW0089565646I_RA_5, CW0089565656G_RA_5, CW0089565661F_RA_5
FILTERS: 1000nm BW 15(Used for Red Channel), 750nm BW 5 (Used for Green Channel), 430nm BW 40 (Used for Blue Channel)
©NASA/JHUAPL/CIW/AndreaLuck
Feel free to share, giving the appropriate credit and providing a link to the original image or tweet: creativecommons.org/licenses/by/3.0/
Update: now classified in the Met Bull as Oued Namous 001, or ON 001 for short, a rare volcanic angrite.
Angrites are a rare basaltic rocks notable for their porosity, with large vesicles, and green kryptonite-inspired gemstones scattered throughout. Few have been found. They are among the oldest igneous rocks, with crystallization ages of 4.55 - 4.56 billion years (only EC002 is older, a recent find at 4.565 billion years).
By comparing the reflectance spectra of the angrites to that of several main belt asteroids, two potential parent bodies have been identified: 289 Nenetta and 3819 Robinson.
"Angrites are the most alkali-depleted basalts in the Solar System. While it has been suggested that the planet Mercury may be the source of the angrites, overwhelming evidence has been accumulated that they are fragments of a differentiated asteroid, probably >100 km in radius and with a metal core which, based on 182Hf-182W systematics, formed within ∼2 Ma of CAI formation (which represents the zero-point of the solar system). The origin and source lithologies of these fascinating rocks have been the topics of intense debates, and no consensus has yet been reached. However, the angrites are clearly igneous rocks and not impact melt-rocks or nebular condensates." — Geochemistry 2012
The lack of volatile elements in angrites does argue for an origin in proximity to the Sun, possibly in the vulcanoid belt. The term “vulcanoids” refers to the hypothetical existence of planetoids that used to orbit the Sun closer than Mercury. They have left their original orbits by one or more planetary migration events.
"Angrite meteorites are some of the oldest materials in the solar system. They provide important information on the earliest evolution of the solar system and accretion timescales of protoplanets. The Chromium isotope ratio is homogeneously distributed among angrite meteorites within 13 parts per million, indicating that precursor materials must have experienced a global-scale melting such as a magma ocean. Cooling of the APB (Angrite Parent Body) took at least ∼8 Myr after its differentiation." — Astrophysical Journal, 2019
Update from 2022 study of quenched angrites, offering a new hypothesis... "The quenched angrite meteorites reveal an oxygen isotopic disequilibrium between the matrix and olivine grains, which suggests the mixing of two bodies sourced from differing locations in the Solar System extremely early in Solar System history (< 4 Myr after the formation of calcium-aluminum-rich inclusions). We interpret our findings in terms of an- grite meteorites representing impact-melt rocks rather than shallow magmatic intrusions, recording evidence of impact-driven mixing. This mixing may have taken place in response to the inward migration of giant planets and hence would represent the earliest isotopic evidence for planetary migration in the early Solar System." ...wow! Just, wow.
105g
Ex-Chinese Railways JS 2-8-2 8190 (a JS-B built Datong 1987) heads out of the open cast pit with another load of coal passing an outcrop of dipping Lower Jurassic sandstones, shales and thin coals.
This sequence is part of the overburden while the main coal seams mined at Sandaoling are deeper in the pit and are up to 18m in thickness! The strike direction is east-west parallel to the basin margin and the Tian Shan Mountains to the north. Dips vary from the 30 degrees seen here to almost vertical further to the west.
Now I'm back in Blighty I have had time, and the inclination, to check out the geology. It seems they are non-marine meandering fluvial deposits with local development of braided fluvial and lacustrine deltaic facies and make up a 1500m thick sequence of sandstones, shales and coals of Lower to Middle Jurassic age. Geochemical correlation with four petroleums from the Junggar, Tarim, and Turpan basins strongly suggests that the Jurassic coaly deposits and their lacustrine equivalents downdip are petroleum source rocks. So now you know!
Probably because the overburden contains thin coals which are dumped with the rest of the spoil, in many places around the site the tips are burning which gives an atmospheric feel to early morning shots in the pit.
(Ref: Sedimentology, Organic Geochemistry, and Petroleum
Potential of Jurassic Coal Measures: Tarim, Junggar, and
Turpan Basins, Northwest China; Marc S. Hendrix, Simon C. Brassell, Alan R. Carroll and Stephan A. Graham; AAPG Bulletin, V. 79, No. 7 (July 1995), P. 929–959)
7.23 gram part slice of Northwest Africa 6293 (Diogenite) meteorite (NWA 6293).
This specimen measures 45 mm in length along the bottom edge, 20 mm in width top to bottom and is 2 mm thick. For scale, the black cube has sides of 1 cm (10 mm).
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Found: Northwest Africa, 2010.
Meteorite originally purchased: 17 June 2010 by M. Jost (Space Jewels Switzerland).
Total Known Weight: 575 grams (1 piece).
This specimen: 7.23 gram part slice, polished on one side.
Classification: HED achondrite, Diogenite.
Ferrosilite (mol%): 32.2 - 34.2
Wollastonite: 3.5 - 2.7
The Meteoritical Bulletin gives the following petrography: -
Complex polymict breccia composed mostly of diogenitic clasts and debris, with sparse material derived from cumulate eucrites.
The geochemistry is given in the Meteoritical Bulletin as: -
Orthopyroxene (Fs32.2-34.2 Wo3.5-2.7; Fs60.9 Wo3.5; FeO/MnO = 30.9-31.6), magnesian clinopyroxene (Fs12.8-12.9 Wo44.3-44.6; FeO/MnO = 25.4-25.9), more ferroan clinopyroxene (Fs30.0 Wo41.8; FeO/MnO =33.6), sparse shocked calcic plagioclase, chromite and troilite.
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Diogenites are a type of achondrite (i.e. without chondrules) meteorite believed to originate from deep within the crust of an asteroid, most probably asteroid '4 Vesta'. As such they are part of the HED (Howardite - Eucrite - Diogenite) meteorite clan.
Diogenites are composed of igneous rocks that have slowly solidified deep within the asteroid's crust, forming crystals that are larger than in eucrites. These crystals are mainly magnesium-rich orthopyroxene, with small amounts of plagioclase and olivine.
On April 19, 2018, a flash of light and deafening roar startled the residents of Southwestern Nigeria. There were initial fears of an earthquaker, but NASA’s Center for Near Earth Object Studies (CNEOS) recorded the event: a 0.23 kiloton airburst of an inbound asteroid. Photos released by the Oyo state government showed a large meteorite embedded in the ground, and a tree struck by one of the stones.
Aba Panu is a moderately shocked L-chondrite, which spall their surfaces during the rapid inbound atmospheric heating instead of ablating and forming a black fusion crust (like most meteorites).
As a fresh fall, it has a weathering grade of W0. Very few shock veins inside. 1,842g and 5” x 4” x 3.7”
When I visited the meteorite mecca at ASU, I asked Lawrence Garvie: of the huge array of meteorites here in the collection, which is your favorite? "Aba Panu" he replied, without hesitation. He did the geochemistry analysis for the MetBull entry.
An artifact in the Future Ventures’ 🚀 Space Collection.
Spacecraft: NASA MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging)
Video: flic.kr/p/2ou2Er4
Credit: NASA/JHUAPL/CIW/AndreaLuck
Raw Data processed from: pds-imaging.jpl.nasa.gov/
Time: 2008-10-06 07:11
Altitude 29549 km
PRODUCT IDs: CW0131764530I_RA_5, CW0131764520G_RA_5, CW0131764515F_RA_5
FILTERS: 1000nm BW 15(Used for Red Channel), 750nm BW 5 (Used for Green Channel), 430nm BW 40 (Used for Blue Channel)
Credit:NASA/JHUAPL/CIW/AndreaLuck
Feel free to share, giving the appropriate credit and providing a link to the original image or tweet creativecommons.org/licenses/by/3.0/
Helene Winters, MESSENGER project manager, speaks at an event to celebrate the conclusion of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Mission Thursday, April 16, 2015 at NASA Headquarters in Washington, DC. Panelists at the event shared scientific findings and technical accomplishments of the more than 10 year long mission. MESSENGER is expected to collide into Mercury at a speed of more than 8,750 miles per hour toward the end of April, 2015. Photo Credit: (NASA/Aubrey Gemignani)
Porphyritic metadacite to porphyritic meta-andesite from the Precambrian of Egypt. (cut & polished surface; ~13.2 centimeters across along the base)
“Imperial Porphyry” is a beautiful, important, historically-valuable decorative stone. It was initially quarried during the Egyptian Ptolemaic Dynasty and was also used in the Roman Empire. In later centuries, it was reused in southern and southeastern Europe.
This rock type comes from quarries at Mons Porphyrites in eastern Egypt. The locality name is the basis for the petrologic term “porphyritic”, which refers to a mix of large and small crystals in an igneous rock. Imperial Porphyry rocks are dark reddish to dark purplish with light-colored feldspar phenocrysts. The red-purple colors are the result of alteration of the original rock, which is dark gray-colored. These rocks are part of the Dokhan Volcanics, a greater-than-1 kilometer thick succession of late Precambrian-aged, terrestrial, intermediate to felsic volcanic rocks (= lava flows, volcanic tuffs, and volcanic agglomerates) - they are about 600 million years old. The nature, age, mineralogy, geochemistry, and paleotectonic setting of the Dokhan Volcanics indicate that Imperial Porphyry rocks are lava flows that accompanied subduction zone volcanism during the Pan-African Orogeny. Subduction was followed by a collision event along the Mozambique Belt in the late Precambrian, during which the ancient small supercontinent Gondwana formed (en.wikipedia.org/wiki/Gondwana). Gondwana was part of a larger supercontinent called Pannotia, which rifted apart in the latest Precambrian (upload.wikimedia.org/wikipedia/commons/d/d7/Pannotia.svg).
Geochemical analysis of Imperial Porphyry rocks shows that they are 62.2 to 64.4% silica, which makes them porphyritic quartz andesites and porphyritic dacites. A detailed mineral analysis of Imperial Porphyry is given in Makovicky et al. (2016). The mineralogy shows that the rocks have been subjected to fluid alteration and greenschist-facies metamorphism, possibly related to the Pan-African Orogeny and/or burial metamorphism and/or Red Sea rifting orogenesis. The reddish to purplish coloration is from partial hematitization of mafic minerals. Because the rocks are slightly metamorphosed, they are better referred to as "meta-andesites" and "metadacites".
Stratigraphy: upper Dokhan Volcanics, Ediacaran, upper Neoproterozoic, ~593-602 Ma
Locality: old Roman quarry at Mons Porphyrites, above Wadi Abu Maamel, Red Sea Mountains, Eastern Desert, eastern Egypt
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Geologic info. mostly synthesized from:
Makovicky et al. (2016) - Imperial Porphyry from Gebel Abu Dokhan, the Red Sea Mountains, Egypt, part I. mineralogy, petrology and occurrence. Neues Jahrbuch für Mineralogie Abhandlungen [Journal of Mineralogy and Geochemistry] 193: 1-27.
This shot was taken half a century ago, in a scenic pullout that's still here. Even the roadcut has changed very little. See the geotag for the exact location.
To the rocks-are-boring crowd, this picture is criminally deficient in autumn colors, supernatural sunsets, ducklings, deer, and scenes of rusting Americana. But if you're a rockhound or a geologist, it's a thing of beauty. It shows a required stop in your continuing exploration of the evolution of the Eastern US.
Here's why. Anyone who has hiked in the Mohonk Preserve—for example, farther along on the Undercliff Trail here delineated by the adult couple and the two boys—has seen the Silurian-period Shawangunk Formation. This striking sequence of white conglomerate and sandstone beds forms the ridge's dramatic cuesta scarp and giant slump blocks. However, few visitors notice the less eye-catching Ordovician-period Martinsburg Formation that lies just beneath it.
They may be drab and dark and crumbly, but the Martinsburg's shale, siltstone, and graywacke strata are every bit as interesting. They owe their origin some 460 Ma ago to the convergence of Laurentia (ancestral North America) and a volcanic island arc. As the two terranes collided, the Taconic Mountains rose, and that in turn prompted the formation of a profound depression in the crust just to the west.
Geologists call this kind of downward buckling in front of a mountain range a "foreland basin." Into this basin flooded clay, silt, and dirty sand that formed turbidity currents, which swept with tremendous force downslope to the basin floor.
When these sediments finally came to rest, they did so in repeating patterns of layers known as flysch deposits. And while this is one of the best flysch exposures I've seen, I doubt that the folks shown here were aware that they were standing on ancient submarine avalanches.
Later in the Taconic mountain-building process, continued crustal compression folded and tilted these strata, as can be seen here. The Shawangunk Formation exposed farther uphill represents an even later, Silurian phase of the Taconic Orogeny. Its white quartz pebbles and sand, eroded off the mountains, created molasse units deposited in very shallow water or on land, once the forearc basin was filled. The Shawangunk beds were eventually tilted, too, but by a subsequent mountain-building event.
Sources Consulted for This Essay
- Epstein, Jack B. Stratigraphy of Silurian Rocks in Shawangunk Mountain, Southeastern New York, Including a Historical Review of Nomenclature. U.S. Geological Survey Bulletin 1839-L. Washington, DC: United States Government Printing Office, 1993.
- Feldman, Howard R., Jack B. Epstein, and John A. Smoliga. “The Shawangunk and Martinsburg Formations Revisited: Sedimentology, Stratigraphy, Mineralogy, Geochemistry, Structure and Paleontology.” In New York State Geological Association 81st Annual Meeting Field Trip Guidebook, Frederick W. Vollmer, ed. New Paltz, NY’ SUNY New Paltz, 2009.
- Mohonk Preserve. Undercliff-Overcliff Trail Map. Accessed October 6, 2022. www.mohonkpreserve.org/wp-content/uploads/2021/07/WT_Sugg...
- Schimmrich, Steven. Geology of the Hudson Valley: A Billion Years of History. Self-published by Steven Schimmrich, 2020.
- United States Geological Survey. National Map Viewer. Accessed December 24, 2025. apps.nationalmap.gov/viewer/.
To see the other photos and descriptions in this set, visit my my Geologizing a Cuesta album.
François Tissot stands at the intersection of time and space, not in some distant observatory, but within the quiet hum of his laboratory at Caltech. It is a fitting place for a man who spends his days deciphering messages carried across billions of years, written in fragments of rock that have fallen from the sky.
When Tissot lifts a small vial to the light, he is not simply inspecting a sample. He is peering into the deep history of the solar system, reading isotopic fingerprints left behind by ancient stars and the earliest planetary bodies. His work unravels the story of how cosmic dust became worlds, how disorder gave way to structure, and how Earth emerged as a rare haven for life.
From an early age, Tissot was drawn to the kinds of questions that defy easy answers. Geochemistry offered him a way to explore those questions, blending chemistry, physics, and planetary science into a single pursuit: understanding the origins of planets, including our own.
In the specialized field of isotope geochemistry, Tissot acts as both detective and historian. His focus is on meteorites, ancient messengers that predate the Earth itself. By analyzing subtle variations in isotopic compositions, he reconstructs the conditions of a time when the solar system was a chaotic swirl of gas and dust. These meteorites carry within them the story of how planets formed and evolved, long before Earth had oceans or an atmosphere.
What distinguishes Tissot is not only his technical expertise, reflected in the precision instruments that fill his lab, but also the quiet reverence with which he approaches his work. Each meteorite is more than a specimen. It is a fragment of cosmic history, and Tissot listens carefully to what it has to say.
His research reaches beyond academic curiosity. By tracing the isotopic evolution of planetary bodies, Tissot sheds light on fundamental questions: Why did Earth develop in a way that supports life, while other planets did not? How did water arrive here? What forces shaped the continents beneath our feet? These are not abstract puzzles. They are keys to understanding our place in the universe.
Despite the vast timescales and cosmic scope of his research, Tissot remains grounded. Colleagues describe him as thoughtful and precise, with a passion that reveals itself in the details. He finds wonder not in dramatic declarations, but in the patient work of uncovering nature’s oldest secrets.
In a world preoccupied with the immediate, Tissot’s focus is deep in the past, illuminating the chain of events that led to the present moment. Watching him examine a sliver of meteorite is witnessing a conversation across billions of years.
It is a quiet reminder that answers to the biggest questions are often hidden in the smallest places. With patience and imagination, even a fragment of stone can reveal how a solar system came to be.
Emerging consensus that the Thera volcano in 1500 BC destroyed the mythical Atlantis!
The Minoan eruption of Thera (or Santorini) in the Bronze Age (dated via radiocarbon dating of one sample to 1630-1600 BC,[1] corroborated by many other samples to 1654-1611 BC;[2] but 1525-1500 BC archaeologically, according to the Conventional Egyptian chronology[3]) has become the most famous single event in the Aegean Sea before the fall of Troy. The eruption would likely have caused a significant climate upset for the eastern Mediterranean region and possibly the entire world. With an estimated Dense-Rock Equivalent up to 60 cubic kilometers,[4] it was one of the largest volcanic eruptions on Earth during the last few thousand years. The name "Minoan eruption" refers to the Minoan civilization on Crete, which some scholars think was heavily disturbed by this eruption.
Physical effects of the eruption
The violent eruption was centered on a small island just north of the existing island of Nea Kameni in the centre of the caldera. The caldera itself was formed several hundred thousand years ago by collapse of the centre of a circular island caused by the emptying of the magma chamber during an eruption. It has been filled several times by ignimbrite since then and the process repeated, most recently 21,000 years ago. The northern part of the caldera was refilled by the volcano and then collapsed again during the Minoan eruption. Before the eruption, the caldera formed a nearly continuous ring with the only entrance between the tiny island of Aspronisi and Thera. The eruption destroyed the sections of the ring between Aspronisi and Therasia, and between Therasia and Thera, creating two new channels.
On Santorini, there is a 60 m thick deposit of white tephra thrown from the eruption that overlies the soil that marks the ground level before the eruption. The layer is divided into three fairly distinct bands indicating different phases of the eruption.[5]
Since no bodies have been found at the Akrotiri site, it is assumed that there were early indications of vulcanism which would induce the local population to leave the area. The thinness of the first ash layer and the likelihood of this layer being eroded by winter rains indicate that the volcano may have given warning at most months in advance and not years as previously believed.[6] Further archeological excavations at the site may eventually result in finding bodies similar to those found at Pompeii and Herculaneum as a result of the eruption of Mount Vesuvius.
The Minoan eruption, considered a classic plinian type, created a plume 30-35 km in height, extending into the stratosphere, along with magma coming into contact with the shallow marine embayment, resulted in a violent phreatic eruption. The eruption also generated a 35 to 150 m high tsunami that devastated the north coast of Crete, 110 km (70 mi) away. The tsunami impacted coastal towns such as Amnisos, where building walls have been knocked out of alignment. The tsunami would also certainly have eliminated the Minoan fleet along Crete's northern shore. On the island of Anaphi, 27 km to the east, ash layers 10 feet deep have been found, as well as pumice layers on slopes 250 meters above sea level. Elsewhere in the Mediterranean there are pumice deposits that could be caused by the Thera eruption.[7] Ash layers in cores drilled from the seabed and from lakes in Turkey, however, show that the heaviest ashfall was towards the east and northeast of Santorini. (Ash found in Crete is now known to have been from a precursory phase of the eruption, some weeks or months before the main eruptive phases, and would have had little impact.[8] Santorini ash deposits were at one time claimed to have been found in the Nile delta, but this is now known to be a misidentification[9]
The volume of ejecta is estimated to have been up to four times what was thrown into the stratosphere by Krakatau in 1883, a well-recorded event, placing the Volcanic Explosivity Index of the Thera eruption at approximately 6. The Thera volcanic events and subsequent ashfall probably sterilized the island, similar to Krakatau. Recent archaeological research by a team of international scientists in 2006 have revealed that the Santorini event was even more massive than previously thought. It expelled 61 cubic kilometres of magma and rock into Earth's atmosphere compared to previous estimates of only 39 cubic kilometres in 1991.[10] Only the Mount Tambora volcanic eruption of 1815 released more material into the atmosphere.[11]
Dating the volcanic eruption
The Minoan eruption provides a fixed point for aligning the entire chronology of the 2nd millennium BC in the Aegean, because evidence of the eruption occurs throughout the region. However, its exact date is unknown. Current opinion based on radiocarbon dating indicates that the eruption occurred between about 1630 and 1600 BC. These dates, however, conflict with the usual date from archaeology, which is around 1550 BC.
There are numerous archaeological chronologies for the Late Bronze Age, each based on a point of origin for a given material culture. International commerce shipped material culture from Crete, mainland Greece, Cyprus, and Canaan to contexts throughout the eastern Mediterranean. If the Thera eruption could be dated and then associated with a given layer of Cretan (or other) culture, chronologists could use that layer of culture to date other events. Since Thera's material culture at the time of destruction was most like the "Late Minoan IA (LMIA)" culture on Crete, LMIA is the baseline for relative chronology elsewhere. The eruption also aligns with Late Cycladic I (LCI) and Late Helladic I (LHI) - but before "Peloponnesian LHI".[12] As of 1989, Akrotiri had also yielded fragments of nine Syro-Palestinian "Middle Bronze II (MBII)" gypsum vessels.[13]
Some scholars believe the radiocarbon dates to be problematic or completely wrong. Some suggest re-scaling archaeological chronologies with the radiocarbon dates. Others look for a compromise between the archaeological and radiocarbon dates for best fits of both sets of data. Re-scaling archaeological chronologies is controversial, because revising the Aegean Bronze Age chronology could require, by association, revising the well-established conventional Egyptian chronology. The debate about the date continues.
It has long been hoped that information from Greenland ice cores and dendrochronology would determine the date exactly. A large eruption, identified in ice cores and dated to 1644 BC +/- 20 years was suspected to be Santorini. Tree ring data shows that a large event interfering with normal tree growth in America occurred in 1629-1628 BC.[14] These events had formerly been associated together. However, volcanic ash retrieved from an ice core demonstrated that this was not from Santorini[8] leading to the conclusion that the eruption may have occurred on another date.
On 28 April 2006, the journal Science published two research papers arguing that new radiocarbon ages required an eruption date between 1627 and 1600 BC. The research published by Manning et al. in their Science paper analysed 127 samples of wood, bone, and seed collected from various locations in the Aegean, including Santorini, Crete, Rhodes and Turkey. The samples were analysed at three separate labs in Oxford, Vienna, and Heidelberg in order to minimise the chance of a radiocarbon dating error. Manning's research offered a broad dating for the Thera event between 1660 to 1613 BC.[15] Friedrich et al., narrows the time-line for the eruption of Thera to between 1627-1600 BC on a 95% probability, which was facilitated by the rare discovery of an olive tree which had been buried alive on Santorini under a layer of lava rock.[16] Because the tree grew on the island, though, it cannot be certain that its growth was unaffected by volcanic degassing (which would render the radiocarbon ages too early).
The same issue of the journal Science also includes an article quoting eminent archaeologists (Peter Warren and Manfred Bietak) expressing strong scepticism on the new information. At present, then, there is still a dispute between those who believe the radiocarbon data and those who believe in the traditional Aegean chronology. Now that the new radiocarbon dates are published, they will need to be considered by other scholars. It is worth noting that in the past a definitive date for the eruption of Thera has been claimed many times; yet later analysis has always shown such claims to be flawed in some way due to difficulties with radiocarbon methodology or other reasons. Firm conclusions cannot be drawn at the present time.[citation needed]
In 2003 Nicholas Pierce et al. published an article in which they say the late Holocene eruption of the Mount Aniakchak, a volcano in Alaska, is proposed as the most likely source of the glass in the GRIP ice core dating to 1645 BC.[17]
Effects on human civilizations
Volcanic eruptions can impact human civilizations by earthquakes, ashfall, tsunamis, and worldwide climatic effects such as volcanic winters. The impact of Santorini's massive eruption on civilizations of its time are not well understood and are still open to speculation.
Impact on Minoan civilization
Tsunamis from the pyroclastic flows and caldera collapse would have devastated the navy and ports of the Minoans on the north side of Crete. As the Minoans were a sea power and depended on their naval and merchant ships for their livelihood, the Thera eruption must have impacted the Minoans to some degree. Whether these effects were enough to trigger the downfall of the Minoans is under intense debate. Early conclusions held that the ash falling on the eastern half of Crete may have choked off plant life, causing starvation. It was alleged that 7-11 cm of ash fell on Kato Zakro, while 0.5 cm fell on Knossos. However, when field examinations were carried out, this theory has lost some credibility, as no more than 5 mm had fallen anywhere in Crete.
Earlier historians and archaeologists may have thought this because of the depth of pumice found on the sea floor. Recently, though, it has been established this came from a lateral crack in the volcano below sea level.[citation needed] Also, Significant Minoan remains have been found above the LM I-era Thera ash layer, implying that the Thera eruption did not cause the immediate downfall of the Minoans. The Mycenaean conquest of the Minoans occurred in LM II not many years after the eruption, though; and many archaeologists speculate that the eruption induced a crisis in Minoan civilization, which allowed the Mycenaeans to conquer them. For instance, the palaces adopted a "Kouros"-god from the hills in addition to the Minoan goddess. One of these new idols, at Palaikastro, was subsequently vandalised.[18]
Chinese records
Some scientists correlate a volcanic winter from the Minoan eruption with Chinese records documenting the collapse of the Xia dynasty in China. According to the Bamboo Annals, the collapse of the dynasty and the rise of the Shang dynasty (independently approximated to 1618 BC) was accompanied by "'yellow fog, a dim sun, then three suns, frost in July, famine, and the withering of all five cereals".
Impact on Egyptian history
There are no surviving Egyptian records of the eruption. The absence of such records is sometimes attributed to the general disorder in Egypt around the Second Intermediate Period. Scholars J. G. Benett and A. G. Galanopoulos suggest connections between the Thera eruption and the calamities of the Admonitions of Ipuwer, a text from Lower Egypt during the Middle Kingdom or Second Intermediate Period. (During the Second Intermediate Period, Lower Egypt came under the rule of "Hyksos" from Canaan.)[19]
Benett and Galanopoulos have apparently used a date for the Admonitions Of Ipuwer/an Egyptian Sage suggested by Jon Van Setters, as he wrote on this subjest for his dissertation and came to this conclusion. Other dates are possible, including the reign of Hatsheput. Others link heavy rainstorms that devastated much of Egypt and were described on the Tempest Stela of Ahmose I to short term climatic changes caused by the Theran eruption[20][21][22][23]
The theory is not supported by current archaeological evidence which show no pumice layers at Avaris or elsewhere Lower Egypt during the reigns of Ahmose I and Thutmosis III. It has been argued that the damage from this storm may have been caused by an earthquake caused by the Thera Eruption; however, it has also been argued on account of the verbs used in the stela--specifically "entering", "dismantling", "hacking up", and "toppling", all words which indicate defacement by humans--that the damage was caused during war with the Hyksos, and the storm reference is merely an exaggerated figurative reference to chaos, upon which the Pharaoh was imposing order.[23] There is a consensus that Egypt, being far away from areas of significant seismic activity, would not be significantly affected by an earthquake in the Aegean.[23] Furthermore, other documents, like Hatshepsut's Speos Armedios, depict similar storms, but are clearly speaking figuratively, not literally.[23] It is thus considered likely that this stele is just another such reference to the Pharaoh overcoming the powers of chaos and darkness. Contrarily, it was recorded on the verso of the Rhind Mathematical Papyrus that during Ahmose's Hyksos campaign, "the sky rained", which was an extremely rare event in ancient Egypt, and could quite possibly indicate a rainstorm.[24]
Greek traditions
Irish scholar John V. Luce suggested in 1969 that the eruption of Thera and volcanic fallout inspired myths of the Titanomachy in Hesiod's Theogony. The background of the Titanomachy is known to derive from the Kumarbi cycle, a Bronze Age Hurrian epic from the Lake Van region; but the Titanomachy itself could have picked up elements of western Anatolian folk memory as the tale spread westward. Mott Greene compared Hesiod's lines with volcanic activity, citing Zeus' thunderbolts as volcanic lightning, the boiling earth and sea as a breach of the magma chamber, immense flame and heat as evidence of phreatic explosions, among many other descriptions. Greene concluded that Theogony "leaves no doubt that the phenomena described are volcanic eruptions."[25]
Deucalion's flood is dated in the chronology of Saint Jerome to ca. 1460 BC.
Biblical traditions
One possibility for the effects of Thera's eruption is the origin of the story of the ten plagues to which Egypt was subjected, as proposed by John G. Bennett.[26] According to the Bible, Egypt was beset by such misfortunes as the transforming of their water supply to blood, the infestations of frogs, gnats, and flies, darkness, and violent hail. These effects are compatible with the catastrophic eruption of a volcano in different ways. While the "blood" may have been red tide which is poisonous to human beings, the frogs could have been displaced by the eruption, and their eventual death would have given rise to large numbers of scavenging insects. The darkness could have been the resulting volcanic winter, and the hail the large chunks of ejecta spewn from the volcano. The tsunami that resulted from the Thera eruption is also speculated to have caused the parting of the sea that allowed the Israelites, under Moses, safe passage of the Red Sea, possibly devastating the Egyptian army with the returning wave. Exodus mentions that the Israelites were guided by a "pillar of smoke" during the day and a "pillar of fire" at night, which many scholars have speculated could be references to volcanic activity. However, unambiguous dating of bristlecone pines and other dating methodologies places the Thera eruption at a date significantly different from the supposed dates of the Exodus from Egypt. It is possible that there was a distorted memory amongst the Hebrews of the Theran eruption.[27]
Association with Atlantis
Starting with Spyridon Marinatos' 1939 landmark paper,[28] this cataclysm at Santorini and its possibility to have caused the fall of the Minoan Civilization centered on Crete is sometimes regarded as a likely source or inspiration for Plato's story of Atlantis. Detractors of the theory say that Santorini and Crete combined would not be the size of Plato's Atlantis, and the date of the Minoan collapse does not match Plato's dates for the fall of Atlantis. Scholars such as James W. Mavor and A. G. Galanopoulos argue that the error in date and size could be caused by a mistranscription of the Ancient Egyptian or Mycenaean Linear B symbol for "hundred" as "thousand". There would be little confusion in the visual appearance of hieroglyphic symbols of Egyptian numeric values; but if the Atlantis story does derive from Egypt, it has at some point been translated into Greek, which Galanopoulos suggests is the point of confusion.[29][19]
References
1. ^ New research in Science: date of the largest volcanic eruption in the Bronze Age finally pinpointed (2006). Retrieved on 2007-03-10.
2. ^ Manning, SW et al. (2006). "Chronology for the Aegean Late Bronze Age 1700-1400 B.C.". Science 312: 565-569. DOI:10.1126/science.1125682.
3. ^ Polinger-Foster, K; Ritner, R (1996). "Texts, Storms, and the Thera Eruption". JNES 55: 1-14.
4. ^ Sigurdsson, H et al. (2006). "Marine Investigations of Greece’s Santorini Volcanic Field". Eos 87 (34): 337-348.
5. ^ DA, Davidson (1979). "Aegean Soils During the Second Millennium B.C. with Reference to Thera". Thera and the Aegean World I. Papers presented at the Second International Scientific Congress, Santorini, Greece, August 1978: 725-739, UK: The Thera Foundation. Retrieved on 2007-03-10.
6. ^ G, Heiken; McCoy, F (1990). "Precursory Activity to the Minoan Eruption, Thera, Greece". Thera and the Aegean World III, Vol 2: 79-88, London: The Thera Foundation.
7. ^ Pumice on south Mediterranean - remnant of the Thera eruption? (2004). Retrieved on 2007-03-10.
8. ^ a b Keenan, Douglas (2003). "Volcanic ash retrieved from the GRIP ice core is not from Thera". Geochemistry Geophysics Geosystems 4 (11): 1097. DOI:10.1029/2003GC000608. 1525-2027. Retrieved on 2007-03-10.
9. ^ Guichard, F et al. (1993). "Tephra from the Minoan eruption of Santorini in sediments of the Black Sea". Nature 363 (6430): 610-612. DOI:10.1038/363610a0.
10. ^ Santorini eruption much larger than originally believed (2006). Retrieved on 2007-03-10.
11. ^ Oppenheimer, Clive (2003). "Climatic, environmental and human consequences of the largest known historic eruption: Tambora volcano (Indonesia) 1815". Progress in Physical Geography 27 (2): 230-259.
12. ^ Lolos, YG (1989). On the Late Helladic I of Akrotiri, Thera On the Late Helladic I of Akrotiri, Thera. The Thera Foundation. Retrieved on 2007-03-10.
13. ^ Warren, PM (1989). Summary of Evidence for the Absolute Chronology of the Early Part of the Aegean Late Bronze Age Derived from Historical Egyptian Sources. The Thera Foundation. Retrieved on 2007-03-10.
14. ^ Baillie, MGL (1989). Irish Tree Rings and an Event in 1628 BC. The Thera Foundation. Retrieved on 2007-03-10.
15. ^ Manning, Stuart W; et al. (2006). "Chronology for the Aegean Late Bronze Age 1700-1400 B.C.". Science 312 (5773): 565. DOI:10.1126/science.1125682. Retrieved on 2007-03-10.
16. ^ Friedrich, Walter L; et al. (2006). "Santorini Eruption Radiocarbon Dated to 1627-1600 B.C.". Science 312 (5773): 548. DOI:10.1126/science.1125087. Retrieved on 2007-03-10.
17. ^ Pearce, N. J. G., J. A. Westgate, S. J. Preece, W. J. Eastwood, and W. T. Perkins (2004). "Identification of Aniakchak (Alaska) tephra in Greenland ice core challenges the 1645 BC date for Minoan eruption of Santorini". Geochem. Geophys. Geosyst. 5. DOI:10.1029/2003GC000672.
18. ^ Driessen, Jan (2001). "Crisis Cults on Minoan Crete?". Proceedings of the 8th International Aegean Conference Göteborg, Göteborg University, 12-15 April 2000,, Liège, Belgique: l'Université de Liège. Retrieved on 2007-03-10.
19. ^ a b Galanopoulos, Angelos Georgiou (1969). Atlantis: The Truth Behind the Legend. Bobbs-Merrill Co. ISBN 978-0672506109.
20. ^ EN, Davis (1989). A Storm in Egypt during the Reign of Ahmose. Retrieved on 2007-03-10.
21. ^ Goedicke, Hans (1995). 'Studies about Kamose and Ahmose'. Baltimore: David Brown Book Company, Chapter 3. ISBN 0-9613805-8-6.
22. ^ Foster, Karen Polinger; Ritner, Robert K (1996). "Texts, Storms, and the Theran Eruption". Journal of Near Eastern Studies 57: 1-14.
23. ^ a b c d Wiener, MH; Allen, JP (1998). "Separate Lives: The Ahmose Tempest Stela and the Theran Eruption". Journal of Near Eastern Studies 57: 1-28.
24. ^ Redford, Donald B (1993). Egypt, Canaan, and Israel in Ancient Times. Princeton, NJ: Princeton University Press. ISBN 978-0691000862.
25. ^ Luce, John Victor (1969). The end of Atlantis: New light on an old legend (New Aspects of Antiquity). London: Thames & Hudson. ISBN 978-0500390054.
26. ^ Bennett, John G. (September 1963). "Geo-Physics and Human History: New Light on Plato's Atlantis and the Exodus". Systematics 1 (2). Retrieved on 2007-04-13.
27. ^ The Eruption of Thera: Devastation in the Mediterranean. Retrieved on 2007-04-08.
28. ^ Marinatos, S (1939). "The Volcanic Destruction of Minoan Crete". Antiquity 13: 425-439.
29. ^ Mavor, James (1997). Voyage to Atlantis: The Discovery of a Legendary Land. Park Street Press. ISBN 978-0892816347.
Celestine Spring is one of the most beautiful hot springs in the Fountain Paint Pot area. No documentation exists of how this spring was named - but its blue color does seem to match the deep azure of the sky.
The science of colors of a hot spring:
[ ttps://www.britannica.com/science/hot-spring]
Many of the colours in hot springs are caused by thermophilic (heat-loving) microorganisms, which include certain types of bacteria, such as cyanobacteria, and species of archaea and algae. Many thermophilic organisms grow in huge colonies called mats that form the colourful scums and slimes on the sides of hot springs. The microorganisms that grow in hot springs derive their energy from various chemicals and metals; potential energy sources include molecular hydrogen, dissolved sulfides, methane, iron, ammonia, and arsenic. In addition to geochemistry, the temperature and pH of hot springs play a central role in determining which organisms inhabit them.
Examples of thermophilic microorganisms found in hot springs include bacteria in the genera Sulfolobus, which can grow at temperatures of up to 90 °C (194 °F), Hydrogenobacter, which grow optimally at temperatures of 85 °C (185 °F), and Thermocrinis, which grow optimally at temperatures of 80 °C (176 °F). Thermophilic algae in hot springs are most abundant at temperatures of 55 °C (131 °F) or below.
Fountain Paint Pot Trail, Yellowstone National Park, USA:
Map (link):
[ www.google.co.in/imgres?imgurl=https://4.bp.blogspot.com/... and Spasm Geysers, Fountain Paint Pot trail, Yellowstone National Park images&ved=0ahUKEwjkgubQv8XeAhUC3Y8KHaFRCQ8QMwhNKBowGg&iact=mrc&uact=8 ]
This part of Lower Geyser Basin seen from a half-mile trail has all four of the hydrothermal features found in the park:
Clepsydra Geyser is a geyser in the Lower Geyser Basin of Yellowstone National Park. Clepsydra plays nearly continuously to heights of 45 feet. The name Clepsydra is derived from the Greek word for water clock. Prior to the 1959 Hebgen Lake earthquake, it erupted regularly every three minutes.
Yellowstone National Park has several hydrothermal areas, so what makes the Fountain Paint Pot Area worth visiting? For starters, this part of Lower Geyser Basin has all four of the hydrothermal features found in the park (mudpots, geysers, hot springs, and fumaroles) and you can see them all from a compact half-mile long boardwalk loop. While none of the many Fountain Paint Pot Area geysers are as famous as Old Faithful, they erupt so frequently that you are almost guaranteed a great show on your short hike. Since the walkway passes all four of Yellowstone’s hydrothermal formations, the hike comes with a guaranteed lesson in hydrothermal volcanism.
Hiking the loop in a clockwise direction, you will first pass through a forest of lodgepole pine snags that were drowned and left lifeless by the surrounding hot springs. As you approach the northwest end of the loop, you will spot a lively collection of geysers. Clepsydra Geyser, Fountain Geyser, Jelly Geyser, Jet Geyser, Morning Geyser, Spasm Geyser, and Twig Geyser erupt with various levels of regularity.
As you progress around the walkway toward the northeast corner, you will pass Red Spouter, which behaves like a fumarole, a hot spring, and a mudpot throughout the year. It is like a hot spring in the winter, a muddy reddish pool in the spring and a steaming fumarole in the drier summer and fall. Wrapping down the east side of the boardwalk, you will pass Leather Pool and a slope of fumaroles. These gaps in the surface whistle and hiss as gasses and steam escape from the ground. Just below the fumaroles, where a little more water is present, the trail circles Fountain Paint Pot. These mudpots bubble and pop as globs of mud springs from the surface like miniature trapeze artists.
Continuing downhill, the hydrothermal features become even wetter as you arrive at Silex Spring. Look down into the small blue pool rimmed with white silica. Water spills over the sides of the spring creating an orange-colored surface covered in rippling runoff. These colors are created by thermophiles, heat-loving microorganisms that live in Yellowstone’s hot springs.
( www.hikespeak.com/trails/fountain-paint-pot-trail-yellows... )
Geothermal features of Yellowstone NP- A brief note:
There are four geothermal features found in the park – Hot springs, Geysers, Fumaroles , and Mud volcanoes/pots.
What is a Hot spring?
Hot spring, also called thermal spring, spring with water at temperatures substantially higher than the air temperature of the surrounding region. Most hot springs discharge groundwater that is heated by shallow intrusions of magma (molten rock) in volcanic areas.
Some thermal springs, however, are not related to volcanic activity. In general, the temperature of rocks within the earth increases with depth. The rate of temperature increase with depth is known as the geothermal gradient. In such cases, the water is heated by convective circulation: groundwater percolating downward reaches depths of a kilometre or more where the temperature of rocks is high because of the normal temperature gradient of the Earth’s crust—about 30 °C / kilometer in the first 10 km. The water from hot springs in non-volcanic areas is heated in this manner.
But in active volcanic zones such as Yellowstone National Park, water may be heated by coming into contact with magma (molten rock). The high temperature gradient near magma may cause water to be heated enough that it boils or becomes superheated. If the water becomes so hot that it builds steam pressure and erupts in a jet above the surface of the Earth, it is called a geyser.
[ Warm springs are sometimes the result of hot and cold springs mixing. They may occur within a volcanic area or outside of one. One example of a non-volcanic warm spring is Warm Springs, Georgia (frequented for its therapeutic effects by paraplegic U.S. President Franklin D. Roosevelt, who built the Little White House there) ].
List of hot springs:
[ en.wikipedia.org/wiki/List_of_hot_springs ]
What is a Geyser?
A geyser is formed when water collecting below the surface is heated by a magma source. When the water boils, it rises to the surface. If the water has an unobstructed path, it will pool on the surface in the form of a steaming hot springs. If the passage of the water is imposed upon, the pressure will increase. When the pressure becomes too great, the water converts into to steam. Steam takes up 1,500 times the volume of water, and at this point, the pressure becomes so intense that the steam and surrounding water droplets shoot out of the ground in geyser form, erupting until the pressure has abated and the process starts all over again.
What is a fumarole?
It’s a vent in the Earth’s surface from which steam and volcanic gases are emitted. The major source of the water vapour emitted by fumaroles is groundwater heated by bodies of magma lying relatively close to the surface. Carbon dioxide, sulfur dioxide, and hydrogen sulfide are usually emitted directly from the magma. Fumaroles are often present on active volcanoes during periods of relative quiet between eruptions.
Fumaroles are closely related to hot springs and geysers. In areas where the water table rises near the surface, fumaroles can become hot springs. A fumarole rich in sulfur gases is called a solfatara; a fumarole rich in carbon dioxide is called a mofette. If the hot water of a spring only reaches the surface in the form of steam, it is called a fumarole. [ www.britannica.com/science/fumarole ]
What is a mud volcano/ mud pot/ paint pot?
Usually mud volcanoes are created by hot-spring activity where large amounts of gas and small amounts of water react chemically with the surrounding rocks and form a boiling mud.
Geo-chemistry of mud volcano: Hydrogen sulfide gas rising from magma chamber, as in Yellowstone’s, causes the rotten-egg smell. Microorganisms, or thermophiles, use this gas as a source of energy, and then help turn the gas into sulfuric acid. The acid then breaks down the rocks and soil into mud. Many of the colors seen are vast communities of thermophiles, but some of the yellow is pure sulfur. When iron mixes with sulfur to form iron sulfide, gray and black swirls sometimes appear in the mud (From description of the display board in the park).
If the water of a hot spring is mixed with mud and clay, it is called a mud pot. Variations are the porridge pot (a basin of boiling mud that erodes chunks of the surrounding rock) and the paint pot (a basin of boiling mud that is tinted yellow, green, or blue by minerals from the surrounding rocks).
There are other mud volcanoes, entirely of a nonigneous origin, occur only in oil-field regions that are relatively young and have soft, unconsolidated formations.
Sources: [ www.britannica.com/science/mud-volcano ], and display boards of the YNP.
President Barack Obama, right, and MESSENGER Principal Investigator, director of Columbia University's Lamont-Doherty Earth Observatory, Sean Solomon, listen as a citation is read prior to the President bestowing the National Medal of Science, the nation's top scientific honor to Solomon, Thursday, Nov. 20, 2014 during a ceremony in the East Room of the White House in Washington. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. Photo Credit: (NASA/Bill Ingalls)