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41-476: The Margaret Formation comprises sandstones , sandy siltstones , clay-rich sandstones, coal seams and clay-rich coal seams and volcanic ash beds. The thickness of the formation, which overlies the Mount Moore Formation , reaches about 140 metres (460 ft). Radiometric dating of the formation provided ages of 52.6 ± 1.9 Ma (2010) and 53.7 ± 0.6 Ma (2017). The area where the formation was deposited in

82-470: A thin section using a method like the Gazzi-Dickinson Method . This yields the relative percentages of quartz, feldspar, and lithic grains and the amount of clay matrix. The composition of a sandstone can provide important information on the genesis of the sediments when used with a triangular Q uartz, F eldspar, L ithic fragment ( QFL diagrams ). However, geologist have not been able to agree on

123-525: A lush, rain forest community on a coastal delta plain. Multiple palaeoclimate proxies, ranging from oxygen isotope analysis of vertebrate bones and teeth to palaeofloral analyses, estimate a mild temperate climate for the Eocene High Arctic, where winters remained at or just above freezing and summer temperatures extended to 20 °C (68 °F) or higher. These temperatures are a far cry from today's High Arctic, where central Ellesmere Island experiences

164-403: A mean annual temperature of −19 °C (−2 °F), a warm month mean temperature of about 6 °C (43 °F) and a cold month mean temperature of −38 °C (−36 °F) or colder. Despite the mild Eocene Arctic climate, the vertebrate fauna would have experienced months of total darkness and cooler temperatures during the winter. Recent isotopic work suggests that some mammals, including

205-478: A sandstone goes through as the degree of kinetic processing of the sediments increases. Dott's (1964) sandstone classification scheme is one of many such schemes used by geologists for classifying sandstones. Dott's scheme is a modification of Gilbert's classification of silicate sandstones, and it incorporates R.L. Folk's dual textural and compositional maturity concepts into one classification system. The philosophy behind combining Gilbert's and R. L. Folk's schemes

246-459: A set of boundaries separating regions of the QFL triangle. Visual aids are diagrams that allow geologists to interpret different characteristics of a sandstone. For example, a QFL chart can be marked with a provenance model that shows the likely tectonic origin of sandstones with various compositions of framework grains. Likewise, the stage of textural maturity chart illustrates the different stages that

287-554: A single unit in a large basin, and subsequently separated by faulting. The original extent of the formation is unknown, parts having been uplifted and eroded away, and the current extents largely covered by volcanic and glacial deposits. Early work suggested that the marine Nanaimo Group on Vancouver Island was correlated with the Chuckanut, but the Nanaimo Group is now known to be earlier ( Upper Cretaceous ). The principal outcrops of

328-445: A twofold classification: Cement is what binds the siliciclastic framework grains together. Cement is a secondary mineral that forms after deposition and during burial of the sandstone. These cementing materials may be either silicate minerals or non-silicate minerals, such as calcite. Sandstone that becomes depleted of its cement binder through weathering gradually becomes friable and unstable. This process can be somewhat reversed by

369-837: Is a distinction that can be recognized in the field . In turn, the distinction between an orthoquartzite and a metaquartzite is the onset of recrystallization of existing grains. The dividing line may be placed at the point where strained quartz grains begin to be replaced by new, unstrained, small quartz grains, producing a mortar texture that can be identified in thin sections under a polarizing microscope. With increasing grade of metamorphism, further recrystallization produces foam texture , characterized by polygonal grains meeting at triple junctions, and then porphyroblastic texture , characterized by coarse, irregular grains, including some larger grains ( porphyroblasts .) Sandstone has been used since prehistoric times for construction, decorative art works and tools. It has been widely employed around

410-546: Is composed of quartz or feldspar , because they are the most resistant minerals to the weathering processes at the Earth's surface. Like uncemented sand , sandstone may be imparted any color by impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Because sandstone beds can form highly visible cliffs and other topographic features, certain colors of sandstone have become strongly identified with certain regions, such as

451-530: Is evidence of large-scale (about 110 km ) strike-slip motion on the Straight Creek Fault , starting at 48 Ma. Other related formations (such as the Puget Group and Raging River Formation ) occur east and south of Seattle . Other sedimentary formations of similar age and environment occur throughout southwestern Washington and western Oregon. Various sedimentary formations underlying Puget Sound and

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492-523: Is likely formed during eogenesis. Deeper burial is accompanied by mesogenesis , during which most of the compaction and lithification takes place. Compaction takes place as the sand comes under increasing pressure from overlying sediments. Sediment grains move into more compact arrangements, ductile grains (such as mica grains) are deformed, and pore space is reduced. In addition to this physical compaction, chemical compaction may take place via pressure solution . Points of contact between grains are under

533-431: Is redeposited in the unstrained pore spaces. Mechanical compaction takes place primarily at depths less than 1,000 meters (3,300 ft). Chemical compaction continues to depths of 2,000 meters (6,600 ft), and most cementation takes place at depths of 2,000–5,000 meters (6,600–16,400 ft). Unroofing of buried sandstone is accompanied by telogenesis , the third and final stage of diagenesis. As erosion reduces

574-443: Is that it is better able to "portray the continuous nature of textural variation from mudstone to arenite and from stable to unstable grain composition". Dott's classification scheme is based on the mineralogy of framework grains, and on the type of matrix present in between the framework grains. In this specific classification scheme, Dott has set the boundary between arenite and wackes at 15% matrix. In addition, Dott also breaks up

615-868: The Allenby Formation and Kamloops Group of British Columbia , the Chickaloon Formation of Alaska, and with the Wishbone , Chuckanut and Iceberg Bay Formations . The upper Margaret Formation also has been correlated with the Buchanan Lake Formation of the Eastern Arctic Archipelago. Sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains, cemented together by another mineral. Sandstones comprise about 20–25% of all sedimentary rocks . Most sandstone

656-701: The Global Heritage Stone Resource . In some regions of Argentina, the orthoquartzite-stoned facade is one of the main features of the Mar del Plata style bungalows. Chuckanut Formation The Chuckanut Formation in northwestern Washington (named after the Chuckanut Mountains , near Bellingham ), its extension in southwestern British Columbia (the Huntingdon Formation ), and various related formations in central Washington (including

697-535: The Swauk , Roslyn , Manastash , and Chumstick ) are fluvial sedimentary formations of Eocene age, deposited from about 54  million years ago to around 34  million years ago . The nature of the deposits and included plant fossils indicate a low-lying coastal plain with a subtropical climate; the nature of the sediments indicates metamorphic sources in northeastern Washington. The original Chuckanut/Huntingdon/Swauk formation appears to have been deposited as

738-696: The Chuckanut Formation (marked CK on the map) are in the vicinity of Bellingham , with other outcrops as far south as the Darrington—;Devils Mountain Fault Zone . The Swauk, Roslyn, Chumstick, and Manastash Formations (SW and MA) are on the east side of the Cascade Range and south of Mount Stuart (in the vicinity of Roslyn, Washington ); the offset between these and the Chuckanut/Huntingdon

779-552: The Chuckanut Formation. A fossil turtle shell was recovered from the formation at Clark Point in 1960. The specimen was held in the private collection of the finders until 1981 when it was examined at Western Washington University and identified as an indeterminate member of the Testudinoidea superfamily . Reexamination of the fossil in 2000 showed the specimen belongs to the Trionychidae family of soft shelled turtles. In 2023,

820-588: The Chuckanut continued as convergence of the Crescent Terrane (Olympic Peninsula) initiated strike-slip motion on the Straight Creek Fault (48 Ma), displacing much of the original formation to the north. Continued deposition across the Straight Creek Fault formed the Raging River and Puget Group formations east of Seattle; the former is partly marine, indicating it was probably a large delta, and locating

861-812: The Early Eocene experienced a much warmer climate than the High Arctic today, with mean annual temperatures ranging from 7.6 to 12.9 °C (45.7 to 55.2 °F) and warmest month mean temperatures from 18.2 to 22.2 °C (64.8 to 72.0 °F). The deltaic to swamp environment of the Margaret Formation has provided a diverse fauna of various groups of mammals, birds ( Presbyornis and Gastornis ), reptiles (turtles, snakes, lizards and crocodiles) and fish. The Margaret Formation comprises sandstones , sandy siltstones , clay-rich sandstones, coal seams and clay-rich coal seams and volcanic ash beds. The thickness of

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902-696: The Eocene coast line. Deposition is believed to have largely ended in the late Eocene (around 42 Ma? ) when regional uplift diverted the rivers supplying the sediments, but some deposition may have continued, supplied from local sources. Johnson (1984) estimated a total thickness of 6,000 metres (20,000 ft), which would make the Chuckanut Formation one of the thickest nonmarine sedimentary sequences in North America. But more recent work suggest that, at least in parts, it may be only 2,500 metres (8,200 ft) thick. Various plant and animal fossils have been found in

943-491: The application of tetraethyl orthosilicate (Si(OC 2 H 5 ) 4 ) which will deposit amorphous silicon dioxide between the sand grains. The reaction is as follows. Pore space includes the open spaces within a rock or a soil. The pore space in a rock has a direct relationship to the porosity and permeability of the rock. The porosity and permeability are directly influenced by the way the sand grains are packed together. Sandstones are typically classified by point-counting

984-468: The common minerals most resistant to weathering processes at the Earth's surface, as seen in the Goldich dissolution series . Framework grains can be classified into several different categories based on their mineral composition: Matrix is very fine material, which is present within interstitial pore space between the framework grains. The nature of the matrix within the interstitial pore space results in

1025-456: The depositional environment, older sand is buried by younger sediments, and it undergoes diagenesis . This mostly consists of compaction and lithification of the sand. Early stages of diagenesis, described as eogenesis , take place at shallow depths (a few tens of meters) and are characterized by bioturbation and mineralogical changes in the sands, with only slight compaction. The red hematite that gives red bed sandstones their color

1066-407: The depth of burial, renewed exposure to meteoric water produces additional changes to the sandstone, such as dissolution of some of the cement to produce secondary porosity . Framework grains are sand-sized (0.0625-to-2-millimeter (0.00246 to 0.07874 in) diameter) detrital fragments that make up the bulk of a sandstone. Most framework grains are composed of quartz or feldspar , which are

1107-446: The different types of framework grains that can be present in a sandstone into three major categories: quartz, feldspar, and lithic grains. When sandstone is subjected to the great heat and pressure associated with regional metamorphism , the individual quartz grains recrystallize, along with the former cementing material, to form the metamorphic rock called quartzite . Most or all of the original texture and sedimentary structures of

1148-595: The eastern Olympic Peninsula (such as the Crescent Formation ) are of similar age, but petrographically distinct, and appear to have different sources. The Chuckanut and related formations "are all composed predominantly of fine- to medium-grained sandstones with lesser amounts of interbedded shale, conglomerate, and coal." The sandstones consist of sand eroded from the Mount Stuart massif and probably from uplifted metamorphic sources in northeastern Washington (this

1189-499: The formation were dated to 52.6 ± 1.9 Ma. During the Early Eocene, the climate of much of northern North America was warm and wet, with mean annual temperatures (MAT) as high as 20 °C (68 °F), mean annual precipitation (MAP) of 100 to 150 centimetres (39 to 59 in), mild frost-free winters (coldest month mean temperature >5 °C (41 °F)), and climatic conditions that supported extensive temperate forest ecosystems. Ensemble estimates of mean annual temperatures for

1230-407: The formation, which overlies the Mount Moore Formation , reaches about 140 metres (460 ft). The formation was probably deposited in a lush proximal delta front to delta plain environment , with abundant channels and coal swamps . A volcanic ash layer containing crandallite in the middle of the formation was dated using U-Pb radiometric dating in 2017 to 53.7 ± 0.6 Ma. In 2010, ashes of

1271-433: The greatest strain, and the strained mineral is more soluble than the rest of the grain. As a result, the contact points are dissolved away, allowing the grains to come into closer contact. Lithification follows closely on compaction, as increased temperatures at depth hasten deposition of cement that binds the grains together. Pressure solution contributes to cementing, as the mineral dissolved from strained contact points

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1312-442: The hardness of individual grains, uniformity of grain size and friability of their structure, some types of sandstone are excellent materials from which to make grindstones , for sharpening blades and other implements. Non-friable sandstone can be used to make grindstones for grinding grain, e.g., gritstone . A type of pure quartz sandstone, orthoquartzite, with more of 90–95 percent of quartz, has been proposed for nomination to

1353-660: The high-latitude fossil localities in Arctic Canada ranged from 7.6 to 12.9 °C (45.7 to 55.2 °F), with the range of coldest month mean temperature from 1.3 to 4.2 °C (34.3 to 39.6 °F) and warmest month mean temperatures from 18.2 to 22.2 °C (64.8 to 72.0 °F). Mean annual precipitation estimates for the Margaret Formation ranged between 131 and 180 centimetres (52 and 71 in). The mean summer precipitation has been estimated at 1,134 millimetres (44.6 in) and mean winter precipitation at 366 millimetres (14.4 in). The fossils and sedimentology indicate

1394-452: The hippo-like Coryphodon , were year-round residents in the High Arctic. Given that Gastornis was large (approaching 2 metres (6.6 ft)) and flightless, it likely also was a year-round resident of the Arctic. In contrast, the volant Presbyornis might have been a seasonal migrant to the Arctic. The formation has provided the following fossils: The formation has been correlated with

1435-493: The much lower temperatures and pressures associated with diagenesis of sedimentary rock, but diagenesis has cemented the rock so thoroughly that microscopic examination is necessary to distinguish it from metamorphic quartzite. The term orthoquartzite is used to distinguish such sedimentary rock from metaquartzite produced by metamorphism. By extension, the term orthoquartzite has occasionally been more generally applied to any quartz-cemented quartz arenite . Orthoquartzite (in

1476-464: The narrow sense) is often 99% SiO 2 with only very minor amounts of iron oxide and trace resistant minerals such as zircon , rutile and magnetite . Although few fossils are normally present, the original texture and sedimentary structures are preserved. The typical distinction between a true orthoquartzite and an ordinary quartz sandstone is that an orthoquartzite is so highly cemented that it will fracture across grains, not around them. This

1517-638: The product of physical and chemical weathering of bedrock. Weathering and erosion are most rapid in areas of high relief, such as volcanic arcs , areas of continental rifting , and orogenic belts . Eroded sand is transported by rivers or by the wind from its source areas to depositional environments where tectonics has created accommodation space for sediments to accumulate. Forearc basins tend to accumulate sand rich in lithic grains and plagioclase . Intracontinental basins and grabens along continental margins are also common environments for deposition of sand. As sediments continue to accumulate in

1558-704: The red rock deserts of Arches National Park and other areas of the American Southwest . Rock formations composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs . Quartz-bearing sandstone can be changed into quartzite through metamorphism , usually related to tectonic compression within orogenic belts . Sandstones are clastic in origin (as opposed to either organic , like chalk and coal , or chemical , like gypsum and jasper ). The silicate sand grains from which they form are

1599-417: The sandstone are erased by the metamorphism. The grains are so tightly interlocked that when the rock is broken, it fractures through the grains to form an irregular or conchoidal fracture. Geologists had recognized by 1941 that some rocks show the macroscopic characteristics of quartzite, even though they have not undergone metamorphism at high pressure and temperature. These rocks have been subject only to

1640-612: The world in constructing temples, churches, homes and other buildings, and in civil engineering . Although its resistance to weathering varies, sandstone is easy to work. That makes it a common building and paving material, including in asphalt concrete . However, some types that have been used in the past, such as the Collyhurst sandstone used in North West England , have had poor long-term weather resistance, necessitating repair and replacement in older buildings. Because of

1681-750: Was well before the rise of the Cascade Range), and distributed by rivers across a low-lying coastal plain starting about 54 Ma. These were laid over a metamorphic suite of rocks, those under the Chuckanut now known as the Shuksan, and its correlate under the Swauk known as the Easton. Near Vancouver parts of the Huntingdon Formation lie disconformably on parts of the Cretaceous Nanaimo Group. Deposition of

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