Sandstone

Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) mineral particles or rock fragments.

Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in Bowen's reaction series. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions.

Rock formations that are primarily 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. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity.

Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to tectonic compression within orogenic belts.

Sandstone
Sedimentary rock
USDA Mineral Sandstone 93c3955
Cut slab of sandstone showing Liesegang banding
Composition
Typically quartz and feldspar; lithic fragments are also common. Other minerals may be found in particularly mature sandstone.
Suur Taevaskoda 2010 01
Devonian Sandstone at Suur Taevaskoda, Põlva County, Estonia
PetraSandStoneRock-cut tombs
Kokh-type tombs cut into the multicoloured sandstone of Petra, Jordan

Origins

CoralPinkSandDunesSand
Sand from Coral Pink Sand Dunes State Park, Utah. These are grains of quartz with a hematite coating providing the orange colour. Scale bar is 1.0 mm.

Sandstones are clastic in origin (as opposed to either organic, like chalk and coal, or chemical, like gypsum and jasper).[1] They are formed from cemented grains that may either be fragments of a pre-existing rock or be mono-minerallic crystals. The cements binding these grains together are typically calcite, clays, and silica. Grain sizes in sands are defined (in geology) within the range of 0.0625 mm to 2 mm (0.0025–0.08 inches). Clays and sediments with smaller grain sizes not visible with the naked eye, including siltstones and shales, are typically called argillaceous sediments; rocks with larger grain sizes, including breccias and conglomerates, are termed rudaceous sediments.

Lower antelope 2 md
Red sandstone interior of Lower Antelope Canyon, Arizona, worn smooth by erosion from flash flooding over thousands of years.

The formation of sandstone involves two principal stages. First, a layer or layers of sand accumulates as the result of sedimentation, either from water (as in a stream, lake, or sea) or from air (as in a desert). Typically, sedimentation occurs by the sand settling out from suspension; i.e., ceasing to be rolled or bounced along the bottom of a body of water or ground surface (e.g., in a desert or erg). Finally, once it has accumulated, the sand becomes sandstone when it is compacted by the pressure of overlying deposits and cemented by the precipitation of minerals within the pore spaces between sand grains.

The most common cementing materials are silica and calcium carbonate, which are often derived either from dissolution or from alteration of the sand after it was buried. Colors will usually be tan or yellow (from a blend of the clear quartz with the dark amber feldspar content of the sand). A predominant additional colourant in the southwestern United States is iron oxide, which imparts reddish tints ranging from pink to dark red (terracotta), with additional manganese imparting a purplish hue. Red sandstones are also seen in the Southwest and West of Britain, as well as central Europe and Mongolia. The regularity of the latter favours use as a source for masonry, either as a primary building material or as a facing stone, over other forms of construction.

The environment where it is deposited is crucial in determining the characteristics of the resulting sandstone, which, in finer detail, include its grain size, sorting, and composition and, in more general detail, include the rock geometry and sedimentary structures. Principal environments of deposition may be split between terrestrial and marine, as illustrated by the following broad groupings:

  • Terrestrial environments
  1. Rivers (levees, point bars, channel sands)
  2. Alluvial fans
  3. Glacial outwash
  4. Lakes
  5. Deserts (sand dunes and ergs)
  • Marine environments
  1. Deltas
  2. Beach and shoreface sands
  3. Tidal flats
  4. Offshore bars and sand waves
  5. Storm deposits (tempestites)
  6. Turbidites (submarine channels and fans)

Components

Framework grains

(1)Saunders Quarry-1
Paradise Quarry, Sydney, Australia
GrusSand
Grus sand and the granitoid from which it is derived

Framework grains are sand-sized (0.0625-to-2-millimetre (0.00246 to 0.07874 in) diameter) detrital fragments that make up the bulk of a sandstone.[2][3] These grains can be classified into several different categories based on their mineral composition:

  • Quartz framework grains are the dominant minerals in most clastic sedimentary rocks; this is because they have exceptional physical properties, such as hardness and chemical stability.[4] These physical properties allow the quartz grains to survive multiple recycling events, while also allowing the grains to display some degree of rounding.[4] Quartz grains evolve from plutonic rock, which are felsic in origin and also from older sandstones that have been recycled.
  • Feldspathic framework grains are commonly the second most abundant mineral in sandstones.[4] Feldspar can be divided into two smaller subdivisions: alkali feldspars and plagioclase feldspars. The different types of feldspar can be distinguished under a petrographic microscope.[4] Below is a description of the different types of feldspar.
  • Alkali feldspar is a group of minerals in which the chemical composition of the mineral can range from KAlSi3O8 to NaAlSi3O8, this represents a complete solid solution.[4]
  • Plagioclase feldspar is a complex group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8.[4]
LvMS-Lvm
Photomicrograph of a volcanic sand grain; upper picture is plane-polarised light, bottom picture is cross-polarised light, scale box at left-centre is 0.25 millimetre. This type of grain would be a main component of a lithic sandstone.
  • Lithic framework grains are pieces of ancient source rock that have yet to weather away to individual mineral grains, called lithic fragments or clasts.[4] Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock,[4] although the most common lithic fragments found in sedimentary rocks are clasts of volcanic rocks.[4]
  • Accessory minerals are all other mineral grains in a sandstone; commonly these minerals make up just a small percentage of the grains in a sandstone. Common accessory minerals include micas (muscovite and biotite), olivine, pyroxene, and corundum.[4][5] Many of these accessory grains are more dense than the silicates that make up the bulk of the rock. These heavy minerals are commonly resistant to weathering and can be used as an indicator of sandstone maturity through the ZTR index.[6] Common heavy minerals include zircon, tourmaline, rutile (hence ZTR), garnet, magnetite, or other dense, resistant minerals derived from the source rock.

Matrix

Matrix is very fine material, which is present within interstitial pore space between the framework grains.[4] The interstitial pore space can be classified into two varieties. One is to call the sandstone an arenite, and the other is to call it a wacke. Below is a definition of the differences between the two matrices:

  • Arenites are texturally clean sandstones that are free of or have very little matrix.[5]
  • Wackes are texturally dirty sandstones that have a significant amount of matrix.[3]

Cement

Cement is what binds the siliciclastic framework grains together. Cement is a secondary mineral that forms after deposition and during burial of the sandstone.[4] These cementing materials may be either silicate minerals or non-silicate minerals, such as calcite.[4]

  • Silica cement can consist of either quartz or opal minerals. Quartz is the most common silicate mineral that acts as cement. In sandstone where there is silica cement present, the quartz grains are attached to cement, which creates a rim around the quartz grain called overgrowth. The overgrowth retains the same crystallographic continuity of quartz framework grain that is being cemented. Opal cement is found in sandstones that are rich in volcanogenic materials, and very rarely is in other sandstones.[4]
  • Calcite cement is the most common carbonate cement. Calcite cement is an assortment of smaller calcite crystals. The cement adheres itself to the framework grains, this adhesion is what causes the framework grains to be adhered together.[4]
  • Other minerals that act as cements include: hematite, limonite, feldspars, anhydrite, gypsum, barite, clay minerals, and zeolite minerals.[4]

Pore space

Pore space includes the open spaces within a rock or a soil.[7] 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.[4]

  • Porosity is the percentage of bulk volume that is inhabited by interstices within a given rock.[7] Porosity is directly influenced by the packing of even-sized spherical grains, rearranged from loosely packed to tightest packed in sandstones.[4]
  • Permeability is the rate in which water or other fluids flow through the rock. For groundwater, work permeability may be measured in gallons per day through a one square foot cross section under a unit hydraulic gradient.[7]

Types of sandstone

QFLtriangle
Schematic QFL diagram showing tectonic provinces
Logan Formation Cross Bedding Scour
Cross-bedding and scour in sandstone of the Logan Formation (Lower Carboniferous) of Jackson County, Ohio

All sandstones are composed of the same general minerals. These minerals make up the framework components of the sandstones. Such components are quartz, feldspars,[8] and lithic fragments. Matrix may also be present in the interstitial spaces between the framework grains.[4] Below is a list of several major groups of sandstones. These groups are divided based on mineralogy and texture. Even though sandstones have very simple compositions which are based on framework grains, geologists have not been able to agree on a specific, right way, to classify sandstones.[4] Sandstone classifications are typically done by point-counting a thin section using a method like the Gazzi-Dickinson Method. The composition of a sandstone can have important information regarding the genesis of the sediment when used with a triangular Quartz, Feldspar, Lithic fragment (QFL diagrams). Many geologists, however, do not agree on how to separate the triangle parts into the single components so that the framework grains can be plotted.[4] Therefore, there have been many published ways to classify sandstones, all of which are similar in their general format.

Visual aids are diagrams that allow geologists to interpret different characteristics about a sandstone. The following QFL chart and the sandstone provenance model correspond with each other therefore, when the QFL chart is plotted those points can then be plotted on the sandstone provenance model. The stage of textural maturity chart illustrates the different stages that a sandstone goes through.

  • A QFL chart is a representation of the framework grains and matrix that is present in a sandstone. This chart is similar to those used in igneous petrology. When plotted correctly, this model of analysis creates for a meaningful quantitative classification of sandstones.[9]
  • A sandstone provenance chart allows geologists to visually interpret the different types of places from which sandstones can originate.
  • A stage of textural maturity is a chart that shows the different stages of sandstones. This chart shows the difference between immature, submature, mature, and supermature sandstones. As the sandstone becomes more mature, grains become more rounded, and there is less clay in the matrix of the rock.[4]

Dott's classification scheme

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.[10] The philosophy behind combining Gilbert's and R. L. Folk's schemes 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".[10] 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 the different types of framework grains that can be present in a sandstone into three major categories: quartz, feldspar, and lithic grains.[4]

  • Arenites are types of sandstone that have less than 15% clay matrix in between the framework grains.
    • Quartz arenites are sandstones that contain more than 90% of siliceous grains. Grains can include quartz or chert rock fragments.[4] Quartz arenites are texturally mature to supermature sandstones. These pure quartz sands result from extensive weathering that occurred before and during transport. This weathering removed everything but quartz grains, the most stable mineral. They are commonly affiliated with rocks that are deposited in a stable cratonic environment, such as aeolian beaches or shelf environments.[4] Quartz arenites emanate from multiple recycling of quartz grains, generally as sedimentary source rocks and less regularly as first-cycle deposits derived from primary igneous or metamorphic rocks.[4]
    • Feldspathic arenites are sandstones that contain less than 90% quartz, and more feldspar than unstable lithic fragments, and minor accessory minerals.[4] Feldspathic sandstones are commonly immature or sub-mature.[4] These sandstones occur in association with cratonic or stable shelf settings.[4] Feldspathic sandstones are derived from granitic-type, primary crystalline, rocks.[4] If the sandstone is dominantly plagioclase, then it is igneous in origin.[4]
    • Lithic arenites are characterised by generally high content of unstable lithic fragments. Examples include volcanic and metamorphic clasts, though stable clasts such as chert are common in lithic arenites.[4] This type of rock contains less than 90% quartz grains and more unstable rock fragments than feldspars.[4] They are commonly immature to submature texturally.[4] They are associated with fluvial conglomerates and other fluvial deposits, or in deeper water marine conglomerates.[4] They are formed under conditions that produce large volumes of unstable material, derived from fine-grained rocks, mostly shales, volcanic rocks, and metamorphic rock.[4]
  • Wackes are sandstones that contain more than 15% clay matrix between framework grains.
    • Quartz wackes are uncommon because quartz arenites are texturally mature to supermature.[4]
    • Felspathic wackes are feldspathic sandstone that contain a matrix that is greater than 15%.[4]
    • Lithic wacke is a sandstone in which the matrix greater than 15%.[4]
  • Arkose sandstones are more than 25 percent feldspar.[1] The grains tend to be poorly rounded and less well sorted than those of pure quartz sandstones. These feldspar-rich sandstones come from rapidly eroding granitic and metamorphic terrains where chemical weathering is subordinate to physical weathering.
  • Greywacke sandstones are a heterogeneous mixture of lithic fragments and angular grains of quartz and feldspar or grains surrounded by a fine-grained clay matrix. Much of this matrix is formed by relatively soft fragments, such as shale and some volcanic rocks, that are chemically altered and physically compacted after deep burial of the sandstone formation.

Uses

SydneyUniversity MainBuilding Panorama
The Main Quadrangle of the University of Sydney, a so-called sandstone university
Lampe a graisse - Lascaux
17,000 yr old sandstone oil lamp discovered at the caves of Lascaux, France
MariaImmaculatal Augustiner
Sandstone statue Maria Immaculata by Fidelis Sporer, around 1770, in Freiburg, Germany
Sandstone beverage coasters.jpeg
Sandstone is highly absorbent. These are sandstone beverage coasters.

Sandstone has been used for domestic construction and housewares since prehistoric times, and continues to be used.

Sandstone was a popular building material from ancient times. It is relatively soft, making it easy to carve. It has been widely used around the world in constructing temples, homes, and other buildings.[11] It has also been used for artistic purposes to create ornamental fountains and statues.

Some sandstones are resistant to weathering, yet are easy to work. This makes sandstone a common building and paving material including in asphalt concrete. However, some that have been used in the past, such as the Collyhurst sandstone used in North West England, have been found less resistant, necessitating repair and replacement in older buildings.[12] Because of 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,[13] has been proposed for nomination to the Global Heritage Stone Resource.[14] In some regions of Argentina, the orthoquartzite-stoned facade is one of the main features of the Mar del Plata style bungalows.[14]

See also

Notes

  1. ^ a b "A Basic Sedimentary Rock Classification", L.S. Fichter, Department of Geology/Environmental Science, James Madison University (JMU), Harrisonburg, Virginia, October 2000, JMU-sed-classif (accessed: March 2009): separates clastic, chemical & biochemical (organic).
  2. ^ Dorrik A. V. Stow (2005). Sedimentary Rocks in the Field: A Colour Guide. Manson Publishing. ISBN 978-1-874545-69-9. Retrieved 11 May 2012.
  3. ^ a b Francis John Pettijohn; Paul Edwin Potter; Raymond Siever (1987). Sand and Sandstone. Springer. ISBN 978-0-387-96350-1. Retrieved 11 May 2012.
  4. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am Boggs, J.R., 2000, Principles of sedimentology and stratigraphy, 3rd ed. Toronto: Merril Publishing Company. ISBN 0-13-099696-3
  5. ^ a b Prothero, D. (2004). Sedimentary Geology. New York, NN: W.H. Freeman and Company
  6. ^ Prothero, D. R. and Schwab, F., 1996, Sedimentary Geology, p. 460, ISBN 0-7167-2726-9
  7. ^ a b c Jackson, J. (1997). Glossary of Geology. Alexandria, VA: American Geological Institute ISBN 3-540-27951-2
  8. ^ "Sandstone: Sedimentary Rock - Pictures, Definition & More". geology.com. Retrieved 2017-08-11.
  9. ^ Carozzi, A. (1993). Sedimentary petrography. Englewood Cliffs, NJ: Prentice-Hall ISBN 0-13-799438-9
  10. ^ a b Robert H. Dott (1964). "Wacke, greywacke and matrix; what approach to immature sandstone classification?". SEPM Journal of Sedimentary Research. 34 (3): 625–32. doi:10.1306/74D71109-2B21-11D7-8648000102C1865D.
  11. ^ "Sandstone: Characteristics, Uses And Problems". www.gsa.gov. Retrieved 2017-08-11.
  12. ^ Edensor, T. & Drew, I. Building stone in the City of Manchester: St Ann's Church. Sci-eng.mmu.ac.uk. Retrieved on 2012-05-11.
  13. ^ "Definition of orthoquartzite – mindat.org glossary". www.mindat.org. Retrieved 2015-12-13.
  14. ^ a b Cravero, Fernanda et alia (8 July 2014). "'Piedra Mar del Plata': An Argentine orthoquartzite worthy of being considered as a 'Global Heritage Stone Resource'" (PDF). Geological Society, London. Archived from the original (PDF) on 9 April 2015. Retrieved 3 April 2015.

Bibliography

  • Folk, R.L., 1965, Petrology of sedimentary rocks PDF version. Austin: Hemphill’s Bookstore. 2nd ed. 1981, ISBN 0-914696-14-9.
  • Pettijohn F. J., P.E. Potter and R. Siever, 1987, Sand and sandstone, 2nd ed. Springer-Verlag. ISBN 0-387-96350-2.
  • Scholle, P.A., 1978, A Color illustrated guide to constituents, textures, cements, and porosities of sandstones and associated rocks, American Association of Petroleum Geologists Memoir no. 28. ISBN 0-89181-304-7.
  • Scholle, P.A., and D. Spearing, 1982, Sandstone depositional environments: clastic terrigenous sediments , American Association of Petroleum Geologists Memoir no. 31. ISBN 0-89181-307-1.
  • USGS Minerals Yearbook: Stone, Dimension, Thomas P. Dolley, U.S. Dept. of the Interior, 2005 (format: PDF).

Further reading

Berea Sandstone

Berea Sandstone, also known as Berea Grit, is a sandstone formation in the U.S. states of Michigan, Ohio, Pennsylvania, West Virginia, and Kentucky. It is named after Berea, Ohio. The sandstone has been used as a building stone and is a source of oil and gas.

Brownstone

Brownstone is a brown Triassic-Jurassic sandstone which was once a popular building material. The term is also used in the United States to refer to a townhouse clad in this, or any of a number of aesthetically similar materials.

Buntsandstein

The Buntsandstein (German for coloured or colourful sandstone) or Bunter sandstone is a lithostratigraphic and allostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Buntsandstein predominantly consists of sandstone layers of the Lower Triassic series and is one of three characteristic Triassic units, together with the Muschelkalk and Keuper that form the Germanic Trias Supergroup.

The Buntsandstein is similar in age, facies and lithology with the Bunter of the British Isles. It is normally lying on top of the Permian Zechstein and below the Muschelkalk. In the past the name Buntsandstein was in Europe also used in a chronostratigraphic sense, as a subdivision of the Triassic system. Among reasons to abandon this use was the discovery that its base lies actually in the latest Permian.

Elbe Sandstone Mountains

The Elbe Sandstone Mountains, also called the Elbe sandstone highlands (German: Elbsandsteingebirge; Czech: Labské pískovce) is a mountain range straddling the border between the state of Saxony in southeastern Germany and the North Bohemian region of the Czech Republic, with about three-quarters of the area lying on the German side. The mountains are also referred to as Saxon Switzerland and Bohemian Switzerland in both German and Czech (Sächsische Schweiz and Böhmische Schweiz in German, Saské Švýcarsko and České Švýcarsko in Czech) or simply combined as Saxon-Bohemian Switzerland. In both countries, the mountain range has been declared a national park. The name derives from the sandstone which was carved by erosion. The river Elbe breaks through the mountain range in a steep and narrow valley.

Euramerica

Euramerica (also known as Laurussia – not to be confused with Laurasia, – the Old Red Continent or the Old Red Sandstone Continent) was a minor supercontinent created in the Devonian as the result of a collision between the Laurentian, Baltica, and Avalonia cratons during the Caledonian orogeny, about 410 million years ago. In the Late Carboniferous, tropical rainforests lay over the equator of Euramerica. A major, abrupt change in vegetation occurred when the climate aridified. The forest fragmented and the lycopsids which dominated these wetlands thinned out, being replaced by opportunistic ferns. There was also a great loss of amphibian diversity and simultaneously the drier climate spurred the diversification of reptiles.

Federal Correctional Institution, Sandstone

The Federal Correctional Institution, Sandstone (FCI Sandstone) is a low-security United States federal prison for male offenders in Sandstone, Minnesota. It is operated by the Federal Bureau of Prisons (BoP), a division of the United States Department of Justice.

Not generally acknowledged by the BoP, FCI Sandstone also includes a separate high security wing complete with electric fences and gun towers. This unit, informally known as the "snitch unit" houses high security inmates who have informed on others and would be in jeopardy among the general population. The inmates in this unit are completely segregated from the other Sandstone inmates, although they are served by the same staff.

FCI Sandstone is located approximately 100 miles northeast of Minneapolis/St. Paul and 70 miles southwest of Duluth, Minnesota.

Greensand

Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment, that contains noticeable quantities of rounded greenish grains. These grains are called glauconies and consist of a mixture of mixed-layer clay minerals, such as smectite and glauconite mica. Greensand is also loosely applied to any glauconitic sediment.

Gritstone

Gritstone or grit is a hard, coarse-grained, siliceous sandstone. This term is especially applied to such sandstones that are quarried for building material. British gritstone was used for millstones to mill flour, to grind wood into pulp for paper and for grindstones to sharpen blades. "Grit" is often applied to sandstones composed of angular sand grains. It may commonly contain small pebbles."Millstone Grit" is an informal term for a succession of gritstones which are to be found in the Peak District and Pennines of northern England. These sediments were laid down in the late (upper) Paleozoic era, in the Carboniferous period, in deltaic conditions. The Millstone Grit Group is a formal stratigraphic term for this sequence of rocks.

The gritstone edges of the Peak District are an important climbing area and the rock is much relished by English climbers, among whom it has almost cult status and is often referred to as "God's own rock". The rough surface provides outstanding friction, enabling climbers to stand on or grip the subtlest of features in the rock. (See the main article on rock climbing in the Peak District.)

Jama Masjid, Delhi

The Masjid-i Jahān-Numā (lit. the 'World-reflecting Mosque'), commonly known as the Jama Masjid of Delhi, is one of the largest mosques in India.It was built by Mughal Emperor Shah Jahan between 1644 and 1656 at a cost of 1 million rupees, and was inaugurated by an Imam from Bukhara, present-day Uzbekistan.The mosque was completed in 1656 AD with three great gates, four towers and two 40 metres high minarets constructed with strips of red sandstone and white marble. The courtyard can accommodate more than 25,000 people . There are three domes on the terrace which are surrounded by the two minarets. On the floor, a total of 899 black borders are marked for worshippers. The architectural plan of Badshahi Masjid, built by Shah Jahan's son Aurangzeb at Lahore, Pakistan, is similar to the Jama Masjid.

Leo Petroglyph

The Leo Petroglyph is a sandstone petroglyph containing 37 images of humans and other animals as well as footprints of each. The petroglyph is located near the small village of Leo, Ohio (in Jackson County, Ohio) and is thought to have been created by the Fort Ancient peoples (possibly AD 1000–1650). The area in which the sandstone petroglyph was found is on the edge of an unglaciated Mississippian sandstone cliff 20–65 feet high. To this day, the meanings of the drawings are unknown. On November 10, 1970, it was added to the National Register of Historic Places. The site is maintained by the Ohio History Connection.

Morrison Formation

The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.

It is centered in Wyoming and Colorado, with outcrops in Montana, North Dakota, South Dakota, Nebraska, Kansas, the panhandles of Oklahoma and Texas, New Mexico, Arizona, Utah, and Idaho. Equivalent rocks under different names are found in Canada. It covers an area of 1.5 million square kilometers (600,000 square miles), although only a tiny fraction is exposed and accessible to geologists and paleontologists. Over 75% is still buried under the prairie to the east, and much of its western paleogeographic extent was eroded during exhumation of the Rocky Mountains.

It was named after Morrison, Colorado, where the first fossils in the formation were discovered by Arthur Lakes in 1877. That same year, it became the center of the Bone Wars, a fossil-collecting rivalry between early paleontologists Othniel Charles Marsh and Edward Drinker Cope. In Colorado, New Mexico, and Utah, the Morrison Formation was a major source of uranium ore.

Navajo Sandstone

Navajo Sandstone is a geological formation in the Glen Canyon Group that is spread across the U.S. states of southern Nevada, northern Arizona, northwest Colorado, and Utah as part of the Colorado Plateau province of the United States.

Old Red Sandstone

The Old Red Sandstone is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the northeastern seaboard of North America. It also extends northwards into Greenland and Svalbard. In Britain it is a lithostratigraphic unit (a sequence of rock strata) to which stratigraphers accord supergroup status and which is of considerable importance to early paleontology. For convenience the short version of the term, ORS is often used in literature on the subject. The term was coined to distinguish the sequence from the younger New Red Sandstone which also occurs widely throughout Britain.

Providence Medical Center Amphitheater

Providence Medical Center Amphitheater is an open-air amphitheater located in Bonner Springs, Kansas. It has undergone numerous name changes, opening in 1984 as the Sandstone Center for the Performing Arts, followed by Sandstone Amphitheater, Verizon Wireless Amphitheater, Capitol Federal Park at Sandstone, and most recently, Cricket Wireless Amphitheater.

It is owned by the unified government of Wyandotte County and Kansas City, shares its grounds with the Kansas City Renaissance Festival and National Agricultural Center and Hall of Fame and is located adjacent to the Wyandotte County Park.

Quartzite

Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and red due to varying amounts of iron oxide (Fe2O3). Other colors, such as yellow, green, blue and orange, are due to other minerals.

When sandstone is cemented to quartzite, the individual quartz grains recrystallize along with the former cementing material to form an interlocking mosaic of quartz crystals. Most or all of the original texture and sedimentary structures of the sandstone are erased by the metamorphism. The grainy, sandpaper-like surface becomes glassy in appearance. Minor amounts of former cementing materials, iron oxide, silica, carbonate and clay, often migrate during recrystallization and metamorphosis. This causes streaks and lenses to form within the quartzite.

Orthoquartzite is a very pure quartz sandstone composed of usually well-rounded quartz grains cemented by silica. Orthoquartzite is often 99% SiO2 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 term is also traditionally used for quartz-cemented quartz arenites, and both usages are found in the literature. The typical distinction between the two (since each is a gradation into the other) is a metamorphic quartzite is so highly cemented, diagenetically altered, and metamorphosized so that it will fracture and break across grain boundaries, not around them.

Quartzite is very resistant to chemical weathering and often forms ridges and resistant hilltops. The nearly pure silica content of the rock provides little for soil; therefore, the quartzite ridges are often bare or covered only with a very thin layer of soil and little (if any) vegetation.

Sandstone Valley, Calgary

Sandstone Valley is a suburban neighbourhood in northwest Calgary, Alberta, Canada. Located northwest of the community of Beddington Heights, this primarily low-density residential community is bounded by Country Hills Boulevard to the north, Beddington Trail to the east, Berkshire Boulevard to the south and 14th Street W to the west. The Nose Hill Park is located south-west from the community.

It is represented in the Calgary City Council by the Ward 4 councillor.

Development of this community began in 1982, and was recently completed.

St. Peter Sandstone

The St. Peter Sandstone is an Ordovician formation in the Chazyan stage of the Champlainian series. This sandstone originated as a sheet of sand in clear, shallow water near the shore of a Paleozoic sea and consists of fine-to-medium-size, well-rounded quartz grains with frosted surfaces. The extent of the formation spans north-south from Minnesota to Arkansas and east-west from Illinois into Nebraska and South Dakota. The formation was named by Owen (1847) after the Minnesota River, then known as the St. Peter River. The type locality is at the confluence of the Mississippi and Minnesota Rivers near Fort Snelling, Minnesota. In eastern Missouri the stone consists of quartz sand that is 99.44% silica.

Torridonian

In geology, the term Torridonian is the informal name for the Torridonian Supergroup, a series of Mesoproterozoic to Neoproterozoic arenaceous and argillaceous sedimentary rocks, which occur extensively in the Northwest Highlands of Scotland. The strata of the Torridonian Supergroup are particularly well exposed in the district of upper Loch Torridon, a circumstance which suggested the name Torridon Sandstone, first applied to these rocks by James Nicol. Stratigraphically, they lie unconformably on gneisses of the Lewisian complex and their outcrop extent is restricted to the Hebridean Terrane.

Yesnaby Sandstone Group

The Yesnaby Sandstone Group is a Devonian lithostratigraphic group (a sequence of rock strata) in west Mainland Orkney, Scotland. The name is derived from the locality of Yesnaby where the strata are exposed in coastal cliffs.

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