View allAll Photos Tagged quartzite
Otter Creek in the South Range of the Baraboo Ranges of Wisconsin, USA.
The gravel bars in this creek have abundant, large quartzite clasts derived from nearby outcrops of Baraboo Quartzite. The Baraboo Ranges of southern Wisconsin are dominated by this hard, erosion-resistant Precambrian metamorphic unit. These rocks were originally marine sandstones and have been subjected to metamorphism and structural folding. Original sedimentary structures are preserved, such as cross-bedding and ripple marks. Baraboo Quartzites vary in color from pinkish to dark reddish to grayish. During metamorphism, quartz overgrowths formed over the original quartz sand grains. Long-term, modern weathering can result in original sand grains being released.
This unit has economic significance - it has been quarried historically and in modern times. The quartzite is broken down into gravel-sized pieces for use as railroad ballast and erosion-control rip-rap.
Stratigraphy: Baraboo Quartzite, upper Paleoproterozoic, ~1.7 Ga
Locality: Baxter Hollow (a little downstream of bridge over Otter Creek), South Range of the Baraboo Ranges, southeastern Sauk County, southern Wisconsin, USA
Fuchsitic quartzite in the Precambrian of Wyoming, USA.
The quartzite seen here is richly infused with greenish fuchsite (= chromian muscovite mica). This is a small abandoned quarry where flaggy rocks were excavated for use as decorative stones (see Harris, 2003, p. 9).
Geologic unit: Elmers Rock Greenstone Belt, Archean, 2.54+ Ga
Locality: small abandoned quarry ~0.5 miles north of Tunnel Road, west of Squaw Mountain & south-southeast of Government Peak, eastern flanks of the Laramie Range, far-eastern Albany County, WSW of the town of Wheatland, southeastern Wyoming, USA (vicinity of 41° 55' 00.40" North latitude, 105° 17' 48.53" West longitude)
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Reference cited:
Harris (2003) - Decorative stones of southern Wyoming. Wyoming State Geological Survey Public Information Circular 42.
Crushed Sioux Quartzite (Precambrian) in road at Mitchell, South Dakota, USA.
Extensive outcrops of pinkish, Paleoproterozoic-aged quartzites are present at Falls Park along the Big Sioux River in the city of Sioux Falls, southeastern South Dakota, USA. The quartzites here have nicely water-worn, sculpted surfaces with good, fluvially abraded polish in places. These rocks are part of the Sioux Quartzite (Paleoproterozoic, 1.65-1.70 Ga). Despite being subjected to regional metamorphism, this unit’s original sedimentary features, such as horizontal stratification and ripple marks, are still preserved.
The Sioux Quartzite is a famous erosion-resistant unit in America’s midcontinent. It has formed a long-lived paleotopographic high since Precambrian times - the Sioux tectonic core. This high is part of a NE-SW trending series of paleotopographic highs & depressions known as the Transcontinental Arch, which extends from Arizona to Minnesota (see Carlson, 1999).
The Sioux Quartzite has been quarried in southeastern South Dakota and southwestern Minnesota. Material from these quarries is used as road gravel, sidewalk and paving gravel, and erosion control blocks.
Stratigraphy: Sioux Quartzite, upper Paleoproterozoic, 1.65-1.70 Ga
Locality: roadway next to a motel in Mitchell, South Dakota, USA
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Reference cited:
Carlson (1999) - Transcontinental Arch - a pattern formed by rejuvenation of local features across central North America. Tectonophysics 305: 225-233.
Bow Fiddle Rock is a natural sea arch near Portknockie on the north-eastern coast of Scotland. It is so called because it resembles the tip of a fiddle bow.
It is composed of Quartzite, a metamorphic rock which was originally quartz sandstone. This rock is part of the Cullen Quartzite formation which is seen along the coast between Buckie and Cullen and is some 2,400m thick and dates from the Neoproterozoic Era, 1,000 to 541 million years ago.
These rocks were folded when the ancient continents of Laurentia and Avalonia collided during the Caledonian orogeny. They later became exposed at the surface where sea and weather eroded the structure seen today.
The rock formation is both a tourist attraction and nesting place for sea birds including herring gulls, great black-backed gulls and lesser black-backed gulls.
A bit disappointed that I wasn't able to capture an awesome sunset from the mountaintop, I was greeted by a glowing birch tree as I began the descent through the crack. The white quartzite cliffs helped to brighten the shadows
L'habitant ...... ©TonyAvon2011
The quartzite head of the Egyptian pharoah Amenhotep III. 18th dynasty, about 1400 BC. From a pair of clossal statues set up in the king's mortuary temple.
Skolithos linearis (Haldeman, 1840) - vertical burrows in the Silurian of Tennessee, USA. (cross-section view; camera lens cap for scale)
Trace fossils are any indirect evidence of ancient life. They refer to features in rocks that do not represent parts of the body of a once-living organism. Traces include footprints, tracks, trails, burrows, borings, and bitemarks. Body fossils provide information about the morphology of ancient organisms, while trace fossils provide information about the behavior of ancient life forms. Interpreting trace fossils and determination of the identity of a trace maker can be straightforward (for example, a dinosaur footprint represents walking behavior) or not. Sediments that have trace fossils are said to be bioturbated. Burrowed textures in sedimentary rocks are referred to as bioturbation. Trace fossils have scientific names assigned to them, in the same style & manner as living organisms or body fossils.
Many shallow-water quartzose sandstones have conspicuous, long, vertical burrows called Skolithos linearis. Geologists traditionally consider Skolithos as a burrow of a filter-feeding vermiform organism in a shallow-water, high-energy lithofacies. Most Skolithos occurrences in the geologic record may be safely interpreted as such, but some demonstrably terrestrial examples constructed by other organisms have been discovered (e.g., see Martin, 2006).
The rock with Skolithos trace fossils shown here is often called "piperock". The host rock itself is frequently referred to as "quartzite", even though it's not metamorphic. Very hard, extremely well-cemented quartzose sandstones such as this do mimic true metamorphic quartzites in their physical characteristics.
Stratigraphy: Clinch Formation ("Clinch Quartzite"), Lower Silurian
Locality: large erosion control block on slope, northern side of Rt. 25E, southern side of Clinch Mountain, WNW of the town of Bean Station, northeastern Grainger County, northeastern Tennessee, USA (36° 21' 34.12" North latitude, 83° 21' 05.77" West longitude)
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References:
Haldeman (1840) - Supplement to Number One of “A Monograph of the Limniades, or Freshwater Univalve Shells of North America,” Containing Descriptions of Apparently New Animals in Different Classes, and the Names and Characters of the Subgenera in Paludina and Anculosa. Philadelphia. 3 pp. [= “Miscellaneous Pamphlets on Natural History 14”]
Martin (2006) - Trace Fossils of San Salvador. San Salvador, Bahamas. Gerace Research Center. 80 pp.
I believe this specimen with such rich and waxy golds and reds is from San Carlos. dardilrocks' friend John likely knows more of these finds from their prospecting trip and I look forward to them helping me to provide more information soon. Thanks to John for his generous gift of such beauties. Many of the images from my trip out to the annual rock and gem show at Quartzite, Arizona are going into a set of interest to collectors and travelers.
Quartzite from the Precambrian of South Dakota, USA. (field of view ~7.7 centimeters across)
Quartzite is a common, crystalline-textured, intermediate- to high-grade metamorphic rock. It forms by metamorphism of quartzose sandstones or siltstones. Quartzite can be entirely composed of interlocking quartz crystals, or the original sand grains may still be visible. This rock is hard (H = 7), will not bubble in acid (unlike marble), and can be almost any color.
The term “quartzite” has been used in geology to refer to crystalline, quartzose metamorphic rocks and to hard, well-cemented quartzose sandstones that have not been subjected to metamorphism. It is difficult to not call hard, well-cemented sandstones “quartzite” - for example, the Clinch Quartzite in the Appalachian Mountains and the Eureka Quartzite of the Great Basin in western USA, but the Clinch and Eureka aren’t metamorphic rocks. The term "metaquartzite" has been used by some geologists to refer to crystalline-textured, quartzose rocks that have been metamorphosed. This implies that “quartzite” be restricted to well-cemented, non-metamorphosed sandstones. I don’t often see the term metaquartzite in the geologic literature.
The quartzite sample seen here is from the Precambrian-aged Sioux Quartzite, which outcrops in southeastern South Dakota and southwestern Minnesota. Despite being regionally metamorphed, the unit’s original sedimentary features, such as horizontal stratification, cross-bedding, and ripple marks, are still apparent in outcrop (this sample shows horizontal bedding).
The Sioux Quartzite is a erosion-resistant unit in a long-lived paleotopographic high called the Sioux tectonic core. This high has existed since Precambrian times and is part of a northeast-southwest trending series of paleotopographic highs and depressions known as the Transcontinental Arch, which extends from Arizona to Minnesota (see Carlson, 1999).
Stratigraphy: Sioux Quartzite, upper Paleoproterozoic, 1.65 to 1.70 Ga
Locality: town of Sioux Falls, southeastern South Dakota, USA
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Reference cited:
Carlson (1999) - Transcontinental Arch - a pattern formed by rejuvenation of local features across central North America. Tectonophysics 305: 225-233.
Here and there on mountain trails in the Berkshires, at random, one comes across good-sized stones of what looks like pure quart.
Red quartzite block statue of Teti, Viceroy of Kush: the statue is finely carved, and the features of the squatting body and the plinth are modelled, in contrast with more schematically modelled styles of block statue.
Teti is dressed in a leopard skin, whose tail falls over the plinth beside his right foot, and wears sandals. Around his neck he wears a pendant formed of the 'ankh' sign and the hetep ('peace') sign. On his upper arm is inscribed the cartouche of his sovereign, Tuthmosis III; this does not represent a tattoo, but is a graphic declaration of loyalty first attested in this period. He holds a lotus flower in his left hand.
Emblematic hieroglyphs are inscribed on his hands: on the left hand are signs showing the red crown of Lower Egypt and the moon, and on the right hand signs showing the white crown of Upper Egypt and the sun. Two horizontal lines and nine vertical lines of Middle Egyptian hieroglyphic text are carved at the front, and one horizontal line and three vertical lines on the back pillar; all read right to left.
As the genealogy on this statue makes clear, in this period the title 'King's Son' was awarded to people who were not children of the king. The statue was placed in a chapel in the temple enclosure at Karnak.
Height: 60 centimetres
Width: 29 centimetres
Depth: 39,5 centimetres
Weight: 82 kilograms
1475BC (circa). 18th Dynasty.
from: www.britishmuseum.org
Quartzite & pebbly quartzite in the Precambrian of Ontario, Canada.
Southeastern Canada's ~2.3 billion year old Lorrain Formation includes some beautiful rocks that rockhounds have nicknamed "puddingstone". This refers to whitish-gray quartzites having common pebbles of red jasper.
The Lorrain Formation is somewhat heterolithic. Published studies mention that the unit has arkoses, subarkoses, quartzites, and jasper-pebble conglomerates. The latter two lithologies are present at the glacially-eroded outcrop seen here. The quartzites were originally sandstones. They have been well cemented and somewhat metamorphosed into very hard rocks. The jasper-pebble conglomerates, or "puddingstones", include clasts of white quartz and reddish jaspilites.
Jaspilite is a type of BIF (banded iron formation). BIFs only formed on Earth during the Precambrian - most are Paleoproterozoic in age. They are the # 1 source of iron ore for the world's steel industry. Numerous specific types of BIFs are known. Jaspilite consists of alternating laters of red and silvery-gray, iron-rich minerals. The red layers are hematite or jasper (= hematitic chert). The silver-gray layers are usually rich in magnetite and/or specular hematite. Jaspilite BIFs outcrop in many areas around Lake Superior, for example in Michigan's Upper Peninsula, Minnesota, and Ontario.
During the Paleoproterozoic, BIFs were subaerially exposed as paleo-outcrops and eroded, producing BIF sediments, including many red jasper pebbles. These mixed with quartz-rich sediments.
Regional studies indicate that the Lorrain Formation was deposited in ancient shallow ocean, lake, delta, and shoreline environments.
Stratigraphy: Lorrain Formation, upper Cobalt Group, Huronian Supergroup, Paleoproterozoic, ~2.3 Ga
Locality: Ottertail Lake Northeast Roadcut - glacial knob on the eastern side of Rt. 638, northeast of Ottertail Lake & southeast of Rock Lake, north-northeast of the town of Bruce Mines, southern Ontario, southeastern Canada (46° 23' 30.59" North latitude, 83° 43’ 10.94" West longitude)
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Some info. synthesized from:
Hadley (1970) - Paleocurrents and origin of Huronian Lorrain Formation, Ontario and Quebec. American Association of Petroleum Geologists Bulletin 54: 850.
Reigned 2029-1982 BCE.
Sumerian (Ur III period)--or modern? (See doubts here)
Quartzite with mica and chlorite.
Anonymous loan from a private collection, apparently overseas (pdf).
On display at the Cleveland Museum of Art, Cleveland, Ohio, USA: Anonymous Loan 5.2015.
Both Statues are of Amenhotep III (sometimes read as Amenophis III) 18th Dynasty.
Perhaps the most imposing monument on the West Bank at Luxor are the famous 'Colossi of Memnon'. These massive quartzite (or quartzose sandstone) statues which once flanked the entrance to Amenhotep III's mortuary temple now stand virtually alone in a field at the side of the road to the valley of the kings.
Standing on a hillside just east of Quartzite, AZ, this lonely giant fairly glows in the sunset on its volcanic perch.
This photo taken with the Canon 5D MkII using the Canon 24-105 f4L lens at 84mm, 1/50 sec. @ f16. Processes using Camera Raw, Photoshop CS5, Topaz Adjust 5, and FastStone Editor.
This photo is © copyright-registered material and cannot be used for any purpose without the express written permission of the copyright holder, Kevin D. Renz!
My New Website is now ready and I would certainly appreciate your visits!
The Mary Jo Wegner Arboretum has numerous examples of how important quartzite rock was in the early years of Sioux Falls, as well as how it is still used today.
Cheryl Lehmann - Sioux Falls
This is the western side of western Utah's House Range (looking ~north Route 50, west of Marjum Pass). All the exposed units are Cambrian in age
From the base-upward, the lower, curved slopes consist of Pioche Formation and Tintic Quartzite. Above that is a thick, lighter-colored cliff of Howell Limestone. The darker-colored slopes above that are the Chisholm Shale. The next light-colored cliff above is the Dome Limestone and Whirlwind Formation. The dark-colored are at the very top has outcrops of Swasey Limestone.
Quartzite with red jasper pebbles in the Precambrian of Ontario, Canada.
Southeastern Canada's ~2.3 billion year old Lorrain Formation includes some beautiful rocks that rockhounds have nicknamed "puddingstone". This refers to whitish-gray quartzites having common pebbles of red jasper.
The Lorrain Formation is somewhat heterolithic. Published studies mention that the unit has arkoses, subarkoses, quartzites, and jasper-pebble conglomerates. The latter two lithologies are present at the glacially-eroded outcrop seen here. The quartzites were originally sandstones. They have been well cemented and somewhat metamorphosed into very hard rocks. The jasper-pebble conglomerates, or "puddingstones", include clasts of white quartz and reddish jaspilites.
Jaspilite is a type of BIF (banded iron formation). BIFs only formed on Earth during the Precambrian - most are Paleoproterozoic in age. They are the # 1 source of iron ore for the world's steel industry. Numerous specific types of BIFs are known. Jaspilite consists of alternating laters of red and silvery-gray, iron-rich minerals. The red layers are hematite or jasper (= hematitic chert). The silver-gray layers are usually rich in magnetite and/or specular hematite. Jaspilite BIFs outcrop in many areas around Lake Superior, for example in Michigan's Upper Peninsula, Minnesota, and Ontario.
During the Paleoproterozoic, BIFs were subaerially exposed as paleo-outcrops and eroded, producing BIF sediments, including many red jasper pebbles. These mixed with quartz-rich sediments.
Regional studies indicate that the Lorrain Formation was deposited in ancient shallow ocean, lake, delta, and shoreline environments.
Stratigraphy: Lorrain Formation, upper Cobalt Group, Huronian Supergroup, Paleoproterozoic, ~2.3 Ga
Locality: Ottertail Lake Northeast Roadcut - glacial knob on the eastern side of Rt. 638, northeast of Ottertail Lake & southeast of Rock Lake, north-northeast of the town of Bruce Mines, southern Ontario, southeastern Canada (46° 23' 30.59" North latitude, 83° 43’ 10.94" West longitude)
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Some info. synthesized from:
Hadley (1970) - Paleocurrents and origin of Huronian Lorrain Formation, Ontario and Quebec. American Association of Petroleum Geologists Bulletin 54: 850.
A large dealer area on the Main Drag into Quartzite, Arizona from the west end of town. No, I did not venture over into this area, for it was the rock and gem show I was seeking. Evidently not everyone comes to the annual Quartzite shows for the rocks though, ha ha!
Quartzite from the Precambrian of South Dakota, USA. (~9.6 centimeters across at its widest)
Quartzite is a common, crystalline-textured, intermediate- to high-grade metamorphic rock. It forms by metamorphism of quartzose sandstones or siltstones. Quartzite can be entirely composed of interlocking quartz crystals, or the original sand grains may still be visible. This rock is hard (H = 7), will not bubble in acid (unlike marble), and can be almost any color.
The term “quartzite” has been used in geology to refer to crystalline, quartzose metamorphic rocks and to hard, well-cemented quartzose sandstones that have not been subjected to metamorphism. It is difficult to not call hard, well-cemented sandstones “quartzite” - for example, the Clinch Quartzite in the Appalachian Mountains and the Eureka Quartzite of the Great Basin in western USA, but the Clinch and Eureka aren’t metamorphic rocks. The term "metaquartzite" has been used by some geologists to refer to crystalline-textured, quartzose rocks that have been metamorphosed. This implies that “quartzite” be restricted to well-cemented, non-metamorphosed sandstones. I don’t often see the term metaquartzite in the geologic literature.
The quartzite sample seen here is from the Precambrian-aged Sioux Quartzite, which outcrops in southeastern South Dakota and southwestern Minnesota. Despite being regionally metamorphed, the unit’s original sedimentary features, such as horizontal stratification, cross-bedding, and ripple marks, are still apparent in outcrop.
The Sioux Quartzite is a erosion-resistant unit in a long-lived paleotopographic high called the Sioux tectonic core. This high has existed since Precambrian times and is part of a northeast-southwest trending series of paleotopographic highs and depressions known as the Transcontinental Arch, which extends from Arizona to Minnesota (see Carlson, 1999).
Stratigraphy: Sioux Quartzite, upper Paleoproterozoic, 1.65 to 1.70 Ga
Locality: town of Sioux Falls, southeastern South Dakota, USA
-----------------
Reference cited:
Carlson (1999) - Transcontinental Arch - a pattern formed by rejuvenation of local features across central North America. Tectonophysics 305: 225-233.
Asymmetrical ripple marks in quartzite in the Precambrian of Wisconsin, USA. (geology hammer for scale)
The Baraboo Ranges of southern Wisconsin are dominated by a hard, erosion-resistant Precambrian metamorphic unit called the Baraboo Quartzite. These rocks were originally marine sandstones and have been subjected to metamorphism and structural folding. Original sedimentary structures are preserved, such as cross-bedding and ripple marks. Baraboo Quartzites vary in color from pinkish to dark reddish to grayish. During metamorphism, quartz overgrowths formed over the original quartz sand grains. Long-term, modern weathering can result in original sand grains being released.
This unit has economic significance - it has been quarried historically and in modern times. The quartzite is broken down into gravel-sized pieces for use as railroad ballast and erosion-control rip-rap.
The ridges on the rock shown above are asymmetrical ripples. Asymmetrical ripple marks have a long side and a short side, when viewed in cross-section. They form in a one-directional current by wind or water (in this case, water). The current direction was toward the short side of each ripple.
Stratigraphy: Baraboo Quartzite, upper Paleoproterozoic, ~1.7 Ga
Locality: loose block along the southern shore of Devil's Lake, Devil's Lake State Park, northern part of the South Range of the Baraboo Ranges, southeast of the town of Baraboo, eastern Sauk County, southern Wisconsin, USA
Cross-bedded pebbly quartzite in the Precambrian of Wisconsin, USA.
The Baraboo Ranges of southern Wisconsin are dominated by a hard, erosion-resistant Precambrian metamorphic unit called the Baraboo Quartzite. These rocks were originally marine sandstones and have been subjected to metamorphism and structural folding. Original sedimentary structures are preserved, such as cross-bedding and ripple marks. Baraboo Quartzites vary in color from pinkish to dark reddish to grayish. During metamorphism, quartz overgrowths formed over the original quartz sand grains. Long-term, modern weathering can result in original sand grains being released.
This unit has economic significance - it has been quarried historically and in modern times. The quartzite is broken down into gravel-sized pieces for use as railroad ballast and erosion-control rip-rap.
The tilted layers seen here are cross-bedding, formed in a one-directional current by wind or water - in this case, water.
Stratigraphy: Baraboo Quartzite, upper Paleoproterozoic, ~1.7 Ga
Locality: Tumbled Rocks Trail, northwestern margin of Devil's Lake, Devil's Lake State Park, northern part of the South Range of the Baraboo Ranges, southeast of the town of Baraboo, eastern Sauk County, southern Wisconsin, USA (43° 25' 34.34" North latitude, 89° 44' 06.56" West longitude)
Quartzite with red jasper pebbles in the Precambrian of Ontario, Canada.
Southeastern Canada's ~2.3 billion year old Lorrain Formation includes some beautiful rocks that rockhounds have nicknamed "puddingstone". This refers to whitish-gray quartzites having common pebbles of red jasper.
The Lorrain Formation is somewhat heterolithic. Published studies mention that the unit has arkoses, subarkoses, quartzites, and jasper-pebble conglomerates. The latter two lithologies are present at the glacially-eroded outcrop seen here. The quartzites were originally sandstones. They have been well cemented and somewhat metamorphosed into very hard rocks. The jasper-pebble conglomerates, or "puddingstones", include clasts of white quartz and reddish jaspilites.
Jaspilite is a type of BIF (banded iron formation). BIFs only formed on Earth during the Precambrian - most are Paleoproterozoic in age. They are the # 1 source of iron ore for the world's steel industry. Numerous specific types of BIFs are known. Jaspilite consists of alternating laters of red and silvery-gray, iron-rich minerals. The red layers are hematite or jasper (= hematitic chert). The silver-gray layers are usually rich in magnetite and/or specular hematite. Jaspilite BIFs outcrop in many areas around Lake Superior, for example in Michigan's Upper Peninsula, Minnesota, and Ontario.
During the Paleoproterozoic, BIFs were subaerially exposed as paleo-outcrops and eroded, producing BIF sediments, including many red jasper pebbles. These mixed with quartz-rich sediments.
Regional studies indicate that the Lorrain Formation was deposited in ancient shallow ocean, lake, delta, and shoreline environments.
Stratigraphy: Lorrain Formation, upper Cobalt Group, Huronian Supergroup, Paleoproterozoic, ~2.3 Ga
Locality: Ottertail Lake Northeast Roadcut - glacial knob on the eastern side of Rt. 638, northeast of Ottertail Lake & southeast of Rock Lake, north-northeast of the town of Bruce Mines, southern Ontario, southeastern Canada (46° 23' 30.59" North latitude, 83° 43’ 10.94" West longitude)
------------------------------
Some info. synthesized from:
Hadley (1970) - Paleocurrents and origin of Huronian Lorrain Formation, Ontario and Quebec. American Association of Petroleum Geologists Bulletin 54: 850.
Pipestone County Courthouse, 416 South Hiawatha, Pipestone, Minnesota. This 1902 courthouse is a Beaux Arts style building featuring a Renaissance dome on a clock tower with heavily rusticated masonry and Sioux quartzite. A bronze Lady Justice stands on the dome. The interior is finished with elaborate oak woodwork. A multicolored mantle in the foyer was constructed from pipestone in a Native American motif. The building was constructed by C.H. Peltier of Faribault for $45,175. The architect was George Pass of Mankato, Minnesota. The building was placed on the National Register of Historic Places in 1980.
Horizontally-bedded quartzite in the Precambrian of South Dakota, USA.
Extensive outcrops of pinkish, Paleoproterozoic-aged quartzites are present at Falls Park along the Big Sioux River in the city of Sioux Falls, southeastern South Dakota, USA. The quartzites here have nicely water-worn, sculpted surfaces with good, fluvially abraded polish in places. These rocks are part of the Sioux Quartzite (Paleoproterozoic, 1.65-1.70 Ga). Despite being subjected to regional metamorphism, this unit’s original sedimentary features, such as horizontal stratification and ripple marks, are still preserved.
The Sioux Quartzite is a famous erosion-resistant unit in America’s midcontinent. It has formed a long-lived paleotopographic high since Precambrian times - the Sioux tectonic core. This high is part of a NE-SW trending series of paleotopographic highs & depressions known as the Transcontinental Arch, which extends from Arizona to Minnesota (see Carlson, 1999).
The Sioux Quartzite has been quarried in southeastern South Dakota and southwestern Minnesota. Material from these quarries is used as road gravel, sidewalk and paving gravel, and erosion control blocks.
Stratigraphy: Sioux Quartzite, upper Paleoproterozoic, 1.65-1.70 Ga
Locality: Falls Park, near Sioux Falls along the Big Sioux River in the town of Sioux Falls, southeastern South Dakota, USA
------------------
Reference cited:
Carlson (1999) - Transcontinental Arch - a pattern formed by rejuvenation of local features across central North America. Tectonophysics 305: 225-233.
Horizontally-bedded quartzite in the Precambrian of South Dakota, USA.
Extensive outcrops of pinkish, Paleoproterozoic-aged quartzites are present at Falls Park along the Big Sioux River in the city of Sioux Falls, southeastern South Dakota, USA. The quartzites here have nicely water-worn, sculpted surfaces with good, fluvially abraded polish in places. These rocks are part of the Sioux Quartzite (Paleoproterozoic, 1.65-1.70 Ga). Despite being subjected to regional metamorphism, this unit’s original sedimentary features, such as horizontal stratification and ripple marks, are still preserved.
The Sioux Quartzite is a famous erosion-resistant unit in America’s midcontinent. It has formed a long-lived paleotopographic high since Precambrian times - the Sioux tectonic core. This high is part of a NE-SW trending series of paleotopographic highs & depressions known as the Transcontinental Arch, which extends from Arizona to Minnesota (see Carlson, 1999).
The Sioux Quartzite has been quarried in southeastern South Dakota and southwestern Minnesota. Material from these quarries is used as road gravel, sidewalk and paving gravel, and erosion control blocks.
Stratigraphy: Sioux Quartzite, upper Paleoproterozoic, 1.65-1.70 Ga
Locality: Falls Park, near Sioux Falls along the Big Sioux River in the town of Sioux Falls, southeastern South Dakota, USA
------------------
Reference cited:
Carlson (1999) - Transcontinental Arch - a pattern formed by rejuvenation of local features across central North America. Tectonophysics 305: 225-233.
Quartzite with red jasper pebbles in the Precambrian of Ontario, Canada.
Southeastern Canada's ~2.3 billion year old Lorrain Formation includes some beautiful rocks that rockhounds have nicknamed "puddingstone". This refers to whitish-gray quartzites having common pebbles of red jasper.
The Lorrain Formation is somewhat heterolithic. Published studies mention that the unit has arkoses, subarkoses, quartzites, and jasper-pebble conglomerates. The latter two lithologies are present at the glacially-eroded outcrop seen here. The quartzites were originally sandstones. They have been well cemented and somewhat metamorphosed into very hard rocks. The jasper-pebble conglomerates, or "puddingstones", include clasts of white quartz and reddish jaspilites.
Jaspilite is a type of BIF (banded iron formation). BIFs only formed on Earth during the Precambrian - most are Paleoproterozoic in age. They are the # 1 source of iron ore for the world's steel industry. Numerous specific types of BIFs are known. Jaspilite consists of alternating laters of red and silvery-gray, iron-rich minerals. The red layers are hematite or jasper (= hematitic chert). The silver-gray layers are usually rich in magnetite and/or specular hematite. Jaspilite BIFs outcrop in many areas around Lake Superior, for example in Michigan's Upper Peninsula, Minnesota, and Ontario.
During the Paleoproterozoic, BIFs were subaerially exposed as paleo-outcrops and eroded, producing BIF sediments, including many red jasper pebbles. These mixed with quartz-rich sediments.
Regional studies indicate that the Lorrain Formation was deposited in ancient shallow ocean, lake, delta, and shoreline environments.
Stratigraphy: Lorrain Formation, upper Cobalt Group, Huronian Supergroup, Paleoproterozoic, ~2.3 Ga
Locality: Ottertail Lake Northeast Roadcut - glacial knob on the eastern side of Rt. 638, northeast of Ottertail Lake & southeast of Rock Lake, north-northeast of the town of Bruce Mines, southern Ontario, southeastern Canada (46° 23' 30.59" North latitude, 83° 43’ 10.94" West longitude)
------------------------------
Some info. synthesized from:
Hadley (1970) - Paleocurrents and origin of Huronian Lorrain Formation, Ontario and Quebec. American Association of Petroleum Geologists Bulletin 54: 850.
Quartzite statue of Ankhrekhu
From Egypt
12th Dynasty, 1985-1795 BC
A Middle Kingdom official wearing a cloak
Egyptian sculpture is often thought to consist only of massive and regal statues of the pharaohs of Egypt. However, there exist also more intimate images, so-called 'private' sculptures, made to be placed in the tombs of ordinary people.
This statue shows the official Ankhrekhu seated, and wrapped in a cloak, a common feature of the private statuary of the Middle Kingdom (about 2040-1750 BC). He has a slightly serious expression, and larger than average ears, common in that period in both private and royal statues. He wears a wig that was conventional in the Middle Kingdom (about 2040-1750 BC). The folds of the drapery over the figure are carefully carved, and the fringed edge to the material of the cloak is indicated.
Ankhrekhu was an official with important courtly titles that indicate his rank. One of his main functions seems to have been that of overseer of priests, but it is not known in which temple, or of which god.
Height: 71.000 cm Width: 45.800 cm
Bequeathed by Lady Coote.
from: www.britishmuseum.org
The Zabriskie Quartzite is a hard, cliff-forming unit originally deposited as marine sands along a continental margin during the Lower Cambrian period about 560 million years. It is well exposed here at Aguereberry Point. Death Valley National Park. Inyo Co., Calif.
Fluvially-polished quartzite in the Precambrian of South Dakota, USA.
Extensive outcrops of pinkish, Paleoproterozoic-aged quartzites are present at Falls Park along the Big Sioux River in the city of Sioux Falls, South Dakota. The quartzites here have nicely water-worn, sculpted surfaces. These rocks are part of the Sioux Quartzite, which consists of 1.65 to 1.70 billion year old metamorphosed sandstones. Despite the metamorphism, original sedimentary features such as horizontal stratification, cross-bedding, and ripple marks are still preserved.
The Sioux Quartzite is an erosion-resistant unit in America’s midcontinent. It has formed a long-lived paleotopographic high since Precambrian times - the Sioux tectonic core. This high is part of a northeast-to-southwest trending series of paleotopographic highs & depressions known as the Transcontinental Arch, which extends from Arizona to Minnesota (see Carlson, 1999).
Quarries of Sioux Quartzite occur in southeastern South Dakota and southwestern Minnesota. The rocks are used as building stone, road gravel, sidewalk and paving gravel, and erosion control material.
The shiny areas on this Sioux Quartzite surface are fluvial polish. During times of energetic flow by the nearby Big Sioux River, abrasion from sediments have eroded, scoured, smoothed, and polished the rocks. Naturally polished rocks can also form by glacial action (glacial polish), faulting (structural polish or fault polish), and wind action, which results in ventifacts.
Stratigraphy: Sioux Quartzite, upper Paleoproterozoic, 1.65-1.70 Ga
Locality: Falls Park, near Sioux Falls along the Big Sioux River in the town of Sioux Falls, southeastern South Dakota, USA
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Reference cited:
Carlson (1999) - Transcontinental Arch - a pattern formed by rejuvenation of local features across central North America. Tectonophysics 305: 225-233.