View allAll Photos Tagged Basalt
(Web camera screen capture video clip taken on 7 May 2021)
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Iceland is a volcanic island in the North Atlantic Ocean between Britain and Greenland. It is situated on the Mid-Atlantic Ridge, along which the North American Plate and the Eurasian Plate separate and new oceanic crust forms. Seismicity in the area is due to subsurface magma movement from hotspot (mantle plume) activity, as well as seafloor spreading (= tectonic divergence). Magma reaching the surface results in volcanic eruptions. Some famous eruptions in Iceland include Laki (1783), Surtsey (1963-1967), Eldfell (1973), Hekla (1991, 2000), Eyjafjallajökull (2010), and Grimsvötn (2011).
On 19 March 2021, a basaltic lava flow eruption started in the Geldingadalur Valley, next to the Fagradalsfjall Volcano in southwestern Iceland's Reykjanes Peninsula. This followed a swarm of about 50,000 earthquakes that occurred during the previous month. The eruption reportedly started as a fissure eruption - lava was spewed from an extensive crack in the ground. This evolved into a short chain of spatter cones, one of which ended up being larger than the others (= main cone). Subsequent activity resulted in a second sizable spatter cone that developed next to the main cone. Eruptive activity continued into April 2021. Both "original" spatter cones had ceased significant activity by late April 2021.
On 5 April 2021, a new fissure eruption started nearby, close to Merardalir Valley (see: www.flickr.com/photos/jsjgeology/51104474410 ). The fissure eruption rapidly evolved into a line of small spatter cones. On 13 April 2021, additional small spatter cones emerged between the Geldingadalur Valley examples and the near-Merardalir Valley examples.
The active spatter cone seen here has apparently grown from one of the ~mid-April 2021 structures.
Overnight, in the early morning of 2 May 2021, this spatter cone started having pauses and restarts. Pause durations increased as the morning hours progressed. Restarts involved impressively high lava fountaining. This behavior continued the following week, as seen here. In the early morning of 7 May 2021, tall lava fountaining occurred with a ~7.5 to 12 minute periodicity.
Spatter cones are small to very small, steep-sided volcanic cones formed by the accumulation and solidification of blobs of lava that sputtered from a vent. They are usually basaltic in composition.
Perfil del rey Amenemhat III (?). Detalle de un bajorrelieve fragmentado.
• XII dinastía. Reinado de Amenemhat III (Nymaatre).
• Procedencia: Desconocida. Seguramente de un templo.
• Material: Basalto.
• Dimensiones del fragmento: Altura 130 cm. Anchura: 120 cm.
• Conservación: El Cairo. Museo Egipcio. Fachada principal.
Bibliografía:
- Karol Mýsliewiec. Un relief de la fin du Moyen Empire. BIFAO 79 (1979), p. 143-154.
Referencias:
Texto: Juan Rodríguez Lázaro
Diapositiva: Juan R. Lázaro. Tomada en Agosto de 1987.
Streamlined volcanic ejecta.
Locality: Coconino County, Arizona
Size: Specimen is 1.00 inch wide
Catalog: RBas 11
Astronaut Team
Craters of the Moon is used as an analog to present-day Mars, where most evidence for the type of volcanism studied by the project is from a more active past thousands of years ago.
More info here: spacescience.arc.nasa.gov/basalt/events/june-13-july-1-20...
Cliff-side outcropping of pillow basalt (extrusive volcanic rock) along the west side of the port facilities at Port San Luis, north end of San Luis Obispo Bay, between San Luis Obispo and Pismo Beach (Central Coast), California. Pillow basalts form during underwater volcanic eruptions (see Kilauea, Hawaii). These rocks are deep-water Franciscan, probably Jurassic-Cretaceous in age. This was a completely unexpected find for me so I only had my Iphone and the sun was in a bad position for photographing this, but it was such a spectacular outcrop that I had to grab some photos to share.
Twin explorers examine the Cardenas basalt exposure in Carbon Canyon, mile 65 in the Grand Canyon. The formation is named after a Spanish explorer who may have been the first European to see the canyon. There's a memorable scene in the IMAX film showing his surprise at his first look over the south rim. From 35mm slide, April 1987.
The Cardenas basalts underlie all the sedimentary layers in the Grand Canyon, meaning they are the oldest deposits above the bedrock. Yet radiometric dating tests showed a spread of ages, some of which resulted in "younger" ages (by millions of years) than some of the lavas on top of the Grand Canyon, which logically must have been the very youngest of all. The reputable lab doing the dating had not been told where the samples came from, so no dating bias entered into their analysis. This discrepancy points out serious doubts about the reliability of radiometric dating techniques in some situations.
These twin guys on the trip dressed like old west pioneers, but we found out they were in business together creating pipes for pipe organs.
Have been stuck indoors with neuralgia for a bit and going through some old stuff. Hoping to get a bit more active soon!
Alternate view of the aforementioned martian meteorite. Note the presence of tiny fusion crust flakes on this piece. The specimen weight is 0.40 grams. Unclassified and from Big Kahuna.
I dared not go any further. There was a steep drop to the right and no hand rail past the entrance. The basalt was extremely slippery due to the rain. Some of it was painted with non-slip paint, but I didn't trust my balance.
Lichen grows on one of the many large rocks surrounding the gravel parking at Viento State Park's access to the Columbia River.
Best seen against the black basalt.
North Cascades, Mount Baker-Snoqualmie National Forest
Read more about our week hiking in the Mount Baker area on our blog.
Amygdaloidal basalt is a vesicular basalt that has had the original vesicles (gas bubbles in lava) subsequently filled with secondary minerals.
Stratigraphy: unrecorded (but possibly eroded from the Portage Lake Volcanic Series, Bergland Group, middle Keweenawan Supergroup, upper Mesoproterozoic, 1.093 to 1.097 Ga)
Locality: water-worn clast from an unrecorded site (but possibly from the shoreline of Lake Superior)
(cross-section view)
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Igneous rocks form by the cooling and crystallization of hot, molten rock (magma / lava). If this happens at or near the land surface, or on the seafloor, they are extrusive igneous rocks. If this happens deep underground, they are intrusive igneous rocks. Most igneous rocks have a crystalline texture, but some are clastic, vesicular, frothy, or glassy.
Basalt is a common extrusive igneous rock. Basalt is the dominant rock in Earth’s upper oceanic crust. Black lava rocks seen at famous volcanoes such as Mt. Kilauea in Hawaii and Mt. Etna in Sicily are composed of basalt. Basalt has a mafic chemistry. Mafic igneous rocks are generally dark-colored, have 45-52% silica (= SiO2 chemistry) (mafic has also been defined as 45 to 55% silica), are rich in iron (Fe), magnesium (Mg), and calcium (Ca), and are dominated by the minerals plagioclase feldspar, pyroxene, and sometimes olivine (this example has a greenish olivine component).
Basalts have an aphanitic texture (finely crystalline - all or almost all crystals are less than 1 millimeter in size each), but some are porphyritic or coarsely crystalline if the lava flow took time to cool and solidify (e.g., some Proterozoic basalt lavas in the Keweenaw Peninsula of Michigan's Upper Peninsula).
Vesicular basalts (e.g., the sample seen here) are essentially intermediate lithologies between basalts and scorias. Scorias are basaltic rocks with numerous small gas bubbles. Vesicular basalts are basaltic rocks having relatively few, relatively large gas bubbles. Vesicular basalt is more dense than scoria (some scorias will float on water; vesicular basalts won’t do that).
Locality: unrecorded
Black basalt stacks at the black beach of Reynisdrangar on the Vik Coast in South Iceland. According to legend the Reynisdrangar needles were formed when two trolls were trying to drag a three-masted ship to land, when daylight broke they turned to stone.
Basalt is extrusive volcanic rock, this pillow shape occurs when basalt erupts underwater.
i060107 032
I had visited Mount St. Helens a year after its 1980 eruption and brought home this pumice and basalt. They measure roughly 1-1/4 and 1-1/2 inches along their longest axes, respectively. Tonight's episode of the Weather Channel's Forecast Earth was dedicated to volcanoes, including the news that Mount St. Helens is forming another lava dome.
My visit -- including the sight of a fawn nibbling a spring-green shoot poking out of the ash -- had inspired this poem:
Sanctuary, Mount St. Helens
The softened grey plain under my feet
tames roaring magma. I sink gently,
in a free-fall
of weights made light
and unfamiliar,
buoyed in a slate tide,
poured in volcanic stasis.
The dull floor etches my footprints
in shattered glass, on a field
with no vanishing point --
and all around me
chipped, denuded peaks
change distance,
edge upon stark edge.
Today I must trust this mountain,
stepping carefully on muffled ground
cued to tremors, murmurs, the silence
of halted growth. A timid fern
curls around a dead, twisted birch woven
in a tangle of birches.
Wild greens lay their thin stalks
over macrames of charred wood
in gauzed lava, shaded
neither wholly black,
nor wholly white.
At any time, the earth might shake
and sway, sifting centuries of dust,
tripping young deer, swallowing pumice and wildflower,
and the air crackle with sirens
echoing like birds off the mountain face, or caught
in the hollowed bones of melting rock.
Below me are pulverized graves, layers
of life and death and
life again.
I hold my breath
to read quick
cryptic traces of seismic thoughts.
And if I stare outward long enough,
I can see new shoots from a simpler age
rise, reborn and ancient
out of motionless ash.
Basalt set in 20k gold. The back is intricately hand engraved with the feet of Lakshmi, the Indian Goddess of Prosperity
This is handmade using traditional Indian techniques over a fire and we use only 20k gold.
SOLD
each piece is a one of a kind
if you are interested in any of these pieces please email me:
samia@karazidesign.com
photo taken by Rupert Lorhalder
Gadara
a Greco-Roman city
--- described by Greek historian, Polybius, in 218 B.C.
--- became a city of the Roman Decapolis in 63 B.C.
--- birthplace of Meleager, one of the most admired Greek poets, in the 1st century B.C.
--- likely place where Jesus drove demons out of a man into swine in the 1st century A.D.
Umm Qais, Irbid Governorate
Jordan
122312
Location
Ganh Da Dia is a small area of interlocking basalt columns sitting at the coast of Tuy An District, Phu Yen Province, Vietnam, which is about 600 km from Ho Chi Minh City. The special rock formation comprises of round and pentagon dishes, stacking on top one another hence its name "Ganh Da Dia" means dish rock promotory in vietnamese. According to scientists, this extrusive volcanic rock was a result of an ancient volcanic eruption, caused by the fast cooling of lava at the surface of the sea. There is another site like this in Ireland and that is the Giant's Causeway.
Time
I arrived before sunrise at 4:00 am when it was still dark. There was a rain on the night before and I was worry that the sun might not come out due to lots of clouds in the sky. However, it finally started to glow and the sunrise was nothing short of a fantastic light show.
Techniques
2-stop hard step grad ND filter for darkening the brighter sky and bringing it into balance with the darker foreground rock.
I should have used a 6-stop ND filter here, which would turn the water into a silky smooth surface, but I forgot.
Circular polarizer filter for increasing the overall color saturation and controlling the reflection on the wet rock.
Hyperfocal distance focusing at 0.8 m for fullframe 16mm at f/11
Single file captured in raw and processed in Lightroom.
Vesicular basalt is formed when many gas pockets are trapped in cooling lava.
This specimen is from the Pu,o'o' eruption on the Big Island of Hawaii.
Two-part explanation, both from Wikipedia:
1. Columbia River Basalt Group.
During late Miocene and early Pliocene epochs, one of the largest flood basalts ever to appear on the Earth's surface engulfed about 163,700 km2 (63,200 sq mi) of the Pacific Northwest, forming a large igneous province with an estimated volume of 174,300 km3 (41,800 cu mi). Eruptions were most vigorous from 17–14 million years ago, when over 99 percent of the basalt was released.
Some time during a 10–15 million-year period, lava flow after lava flow poured out, eventually reaching a thickness of more than 1.8 km (5,900 ft).
Wow - Channel 10's Storm Watch Team would have gone nuts over this one!
en.wikipedia.org/wiki/Columbia_River_Basalt_Group#mediavi...
2. Columnar Basalt.
During the cooling of a thick lava flow, contractional joints or fractures form. If a flow cools relatively rapidly, significant contraction forces build up. While a flow can shrink in the vertical dimension without fracturing, it can't easily accommodate shrinking in the horizontal direction unless cracks form; the extensive fracture network that develops results in the formation of columns. The topology of the lateral shapes of these columns can broadly be classed as a random cellular network. These structures are predominantly hexagonal in cross-section, but polygons with three to twelve or more sides can be observed. The size of the columns depends loosely on the rate of cooling; very rapid cooling may result in very small (<1 cm diameter) columns, while slow cooling is more likely to produce large columns.
You stoners may remember this from the cover of Led Zepplin's Houses of the Holy. Ask me not how I was able to recall this cover instantly after four decades.
en.wikipedia.org/wiki/Houses_of_the_Holy#mediaviewer/File...
