Last updated
Sedimentary rock
USDA Mineral Sandstone 93c3955.jpg
Cut slab of sandstone showing Liesegang banding
Typically quartz and feldspar; lithic fragments are also common. Other minerals may be found in particularly mature sandstone.
Alcove in the Navajo Sandstone MoabAlcove.JPG
Alcove in the Navajo Sandstone
Kokh-type tombs cut into the multicoloured sandstone of Petra, Jordan PetraSandStoneRock-cut tombs.jpg
Kokh-type tombs cut into the multicoloured sandstone of Petra, Jordan

Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones make up about 20 to 25 percent of all sedimentary rocks. [1]


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 the Goldich dissolution series. [2] 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. [3] [4]

Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to tectonic compression within orogenic belts. [5] [6]


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. CoralPinkSandDunesSand.JPG
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). [7] The silicate sand grains from which they form are the product of physical and chemical weathering of bedrock. [8] Weathering and erosion are most rapid in areas of high relief, such as volcanic arcs, areas of continental rifting, and orogenic belts. [9]

Red sandstone interior of Lower Antelope Canyon, Arizona, worn smooth by erosion from flash flooding over thousands of years Lower antelope 2 md.jpg
Red sandstone interior of Lower Antelope Canyon, Arizona, worn smooth by erosion from flash flooding over thousands of years
Tafoni at Twyfelfontein in Namibia Tafoni at Twyfelfontein (Namibia).jpg
Tafoni at Twyfelfontein in Namibia

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. [10]

As sediments continue to accumulate in the depositional environment, older sand is buried by younger sediments, and it undergoes diagenesis. This mostly consists of compaction and lithification of the sand. [11] [12] Early stages of diagenesis, described as eogenesis, take place at shallow depths (a few tens of meters) and is characterized by bioturbation and mineralogical changes in the sands, with only slight compaction. [13] The red hematite that gives red bed sandstones their color is likely formed during eogenesis. [14] [15] Deeper burial is accompanied by mesogenesis, during which most of the compaction and lithification takes place. [12]

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 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. [12]

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 is redeposited in the unstrained pore spaces. [12]

Mechanical compaction takes place primarily at depths above 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). [16]

Unroofing of buried sandstone is accompanied by telogenesis, the third and final stage of diagenesis. [13] As erosion reduces 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. [12]


Framework grains

Paradise Quarry, Sydney, Australia (1)Saunders Quarry-1.jpg
Paradise Quarry, Sydney, Australia
Grus sand and the granitoid from which it is derived GrusSand.JPG
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. [17] [18] These grains can be classified into several different categories based on their mineral composition:

  • 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. [1]
  • Plagioclase feldspar is a complex group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8. [1]
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. LvMS-Lvm.jpg
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.


Matrix is very fine material, which is present within interstitial pore space between the framework grains. [1] The nature of the matrix within the interstitial pore space results in 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. [1] These cementing materials may be either silicate minerals or non-silicate minerals, such as calcite. [1]

Pore space

Pore space includes the open spaces within a rock or a soil. [21] 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. [1]

Types of sandstone

Schematic QFL diagram showing tectonic provinces QFLtriangle.svg
Schematic QFL diagram showing tectonic provinces
Cross-bedding and scour in sandstone of the Logan Formation (Lower Carboniferous) of Jackson County, Ohio Logan Formation Cross Bedding Scour.jpg
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, [22] and lithic fragments. Matrix may also be present in the interstitial spaces between the framework grains. [1] 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. [1] 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. [1] 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.

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. [24] 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". [24] 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. [1]


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

Sandstone has been used since prehistoric times for construction, decorative art works and housewares, and continues to be used. It has been widely employed around the world in constructing temples, homes, and other buildings. [25]

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. [26] 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, [27] has been proposed for nomination to the Global Heritage Stone Resource. [28] In some regions of Argentina, the orthoquartzite-stoned facade is one of the main features of the Mar del Plata style bungalows. [28]

See also


  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Boggs, Sam (2006). Principles of sedimentology and stratigraphy (4th ed.). Upper Saddle River, N.J.: Pearson Prentice Hall. pp. 119–135. ISBN   0131547283.
  2. Prothero & Schwab, Donald R. & Fred (1996). Sedimentary Geology. W. H. Freeman. p. 24. ISBN   0-7167-2726-9.
  3. Swanson, Susan K.; Bahr, Jean M.; Bradbury, Kenneth R.; Anderson, Kristin M. (February 2006). "Evidence for preferential flow through sandstone aquifers in Southern Wisconsin". Sedimentary Geology. 184 (3–4): 331–342. doi:10.1016/j.sedgeo.2005.11.008.
  4. Bjørlykke, Knut; Jahren, Jens (2010). "Sandstones and Sandstone Reservoirs". Petroleum Geoscience: 113–140. doi:10.1007/978-3-642-02332-3_4.
  5. Essentials of Geology, 3rd Edition, Stephen Marshak, p 182
  6. Powell, Darryl. "Quartzite". Mineral Information Institute. Archived from the original on 2009-03-02. Retrieved 2009-09-09.
  7. 1 2 "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).
  8. Leeder, M. R. (2011). Sedimentology and sedimentary basins : from turbulence to tectonics (2nd ed.). Chichester, West Sussex, UK: Wiley-Blackwell. pp. 3–28. ISBN   9781405177832.
  9. Blatt, Harvey; Tracy, Robert J. (1996). Petrology : igneous, sedimentary, and metamorphic (2nd ed.). New York: W.H. Freeman. pp. 241–242, 258–260. ISBN   0716724383.
  10. Blatt and Tracy 1996, pp. 220-227
  11. Blatt and Tracy 1996, pp. 265-280
  12. 1 2 3 4 5 Boggs 2006, pp. 147-154
  13. 1 2 Choquette, P.W.; Pray, L.C. (1970). "Geologic Nomenclature and Classification of Porosity in Sedimentary Carbonates". AAPG Bulletin. 54. doi:10.1306/5D25C98B-16C1-11D7-8645000102C1865D.
  14. Walker, Theodore R.; Waugh, Brian; Grone, Anthony J. (1 January 1978). "Diagenesis in first-cycle desert alluvium of Cenozoic age, southwestern United States and northwestern Mexico". GSA Bulletin. 89 (1): 19–32. doi:10.1130/0016-7606(1978)89<19:DIFDAO>2.0.CO;2.
  15. Boggs 2006, p. 148
  16. Stone, W. Naylor; Siever, Naylor (1996). "Quantifying compaction, pressure solution and quartz cementation in moderately-and deeply-buried quartzose sandstones from the Greater Green River Basin, Wyoming" . Retrieved 2 October 2020.Cite journal requires |journal= (help)
  17. 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.
  18. 1 2 Francis John Pettijohn; Paul Edwin Potter; Raymond Siever (1987). Sand and Sandstone. Springer. ISBN   978-0-387-96350-1 . Retrieved 11 May 2012.
  19. 1 2 Prothero, D. (2004). Sedimentary Geology. New York, NN: W.H. Freeman and Company
  20. Prothero, D. R. and Schwab, F., 1996, Sedimentary Geology, p. 460, ISBN   0-7167-2726-9
  21. 1 2 3 Jackson, J. (1997). Glossary of Geology. Alexandria, VA: American Geological Institute ISBN   3-540-27951-2
  22. "Sandstone: Sedimentary Rock - Pictures, Definition & More". Retrieved 2017-08-11.
  23. Carozzi, A. (1993). Sedimentary petrography. Englewood Cliffs, NJ: Prentice-Hall ISBN   0-13-799438-9
  24. 1 2 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.
  25. "Sandstone: Characteristics, Uses And Problems". Retrieved 2017-08-11.
  26. Edensor, T. & Drew, I. Building stone in the City of Manchester: St Ann's Church. Retrieved on 2012-05-11.
  27. "Definition of orthoquartzite – glossary". Retrieved 2015-12-13.
  28. 1 2 Cravero, Fernanda; et al. (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.


Further reading

Related Research Articles

Schist Medium grade metamorphic rock with lamellar grain

Schist is a medium-grade metamorphic rock formed from mudstone or shale. Schist has medium to large, flat, sheet-like grains in a preferred orientation. It is defined by having more than 50% platy and elongated minerals, often finely interleaved with quartz and feldspar. These lamellar minerals include micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is produced. Schist is often garnetiferous. Schist forms at a higher temperature and has larger grains than phyllite. Geological foliation with medium to large grained flakes in a preferred sheetlike orientation is called schistosity.

Sedimentary rock Rock formed by the deposition and subsequent cementation of material

Sedimentary rocks are types of rock that are formed by the accumulation or deposition of small particles and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus. Before being deposited, the geological detritus was formed by weathering and erosion from the source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers, which are called agents of denudation. Biological detritus was formed by bodies and parts of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies. Sedimentation may also occur as dissolved minerals precipitate from water solution.

Metamorphic rock Rock that was subjected to heat and pressure

Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form". The original rock (protolith) is subjected to heat and pressure, causing profound physical or chemical change. The protolith may be a sedimentary, igneous, or existing metamorphic rock.


The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lithology may refer to either a detailed description of these characteristics, or a summary of the gross physical character of a rock. Examples of lithologies in the second sense include sandstone, slate, basalt, or limestone.

Petrography is a branch of petrology that focuses on detailed descriptions of rocks. Someone who studies petrography is called a petrographer. The mineral content and the textural relationships within the rock are described in detail. The classification of rocks is based on the information acquired during the petrographic analysis. Petrographic descriptions start with the field notes at the outcrop and include macroscopic description of hand specimens. However, the most important tool for the petrographer is the petrographic microscope. The detailed analysis of minerals by optical mineralogy in thin section and the micro-texture and structure are critical to understanding the origin of the rock. Electron microprobe or atom probe tomography analysis of individual grains as well as whole rock chemical analysis by atomic absorption, X-ray fluorescence, and laser-induced breakdown spectroscopy are used in a modern petrographic lab. Individual mineral grains from a rock sample may also be analyzed by X-ray diffraction when optical means are insufficient. Analysis of microscopic fluid inclusions within mineral grains with a heating stage on a petrographic microscope provides clues to the temperature and pressure conditions existent during the mineral formation.

Greywacke A hard, dark sandstone with poorly sorted angular grains in a compact, clay-fine matrix

Greywacke or graywacke is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found in Paleozoic strata. The larger grains can be sand- to gravel-sized, and matrix materials generally constitute more than 15% of the rock by volume. The term "greywacke" can be confusing, since it can refer to either the immature aspect of the rock or its fine-grained (clay) component.

Arkose A type of sandstone containing at least 25% feldspar

Arkose is a detrital sedimentary rock, specifically a type of sandstone containing at least 25% feldspar. Arkosic sand is sand that is similarly rich in feldspar, and thus the potential precursor of arkose.

Quartz arenite

A quartz arenite or quartzarenite is a sandstone composed of greater than 90% detrital quartz, with limited amounts of other framework grains and matrix. It can have higher-than-average amounts of resistant grains, like chert and minerals in the ZTR index.


Arenite is a sedimentary clastic rock with sand grain size between 0.0625 mm (0.00246 in) and 2 mm (0.08 in) and contain less than 15% matrix. The related adjective is arenaceous. The equivalent Greek-derived term is psammite, though this is more commonly used for metamorphosed sediments.

Rock microstructure includes the texture of a rock and the small scale rock structures. The words "texture" and "microstructure" are interchangeable, with the latter preferred in modern geological literature. However, texture is still acceptable because it is a useful means of identifying the origin of rocks, how they formed, and their appearance.

The Folk classification is a technical descriptive classification of sedimentary rocks devised by Robert L. Folk, an influential sedimentary petrologist and Professor Emeritus at the University of Texas.

Clastic rock Sedimentary rocks made of mineral or rock fragments

Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus, chunks and smaller grains of rock broken off other rocks by physical weathering. Geologists use the term clastic with reference to sedimentary rocks as well as to particles in sediment transport whether in suspension or as bed load, and in sediment deposits.

This glossary of geology is a list of definitions of terms and concepts relevant to geology, its sub-disciplines, and related fields. For other terms related to the Earth sciences, see Glossary of geography terms.

Gazzi-Dickinson method Point-counting technique used in geology

The Gazzi-Dickinson method is a point-counting technique used in geology to statistically measure the components of a sedimentary rock, chiefly sandstone. The main focus part of the technique is counting all sand-sized components as separate grains, regardless of what they are connected to. Gazzi-Dickinson point counting is used in the creation of ternary diagrams, such as QFL diagrams.

Lithic sandstone

Lithic sandstones, or lithic arenites, or litharenites, are sandstones with a significant (>5%) component of lithic fragments, though quartz and feldspar are usually present as well, along with some clayey matrix. Lithic sandstones can have a speckled or gray color, and are usually associated with one specific type of lithic fragment.

Igneous rocks are found in Bukit Timah, Woodlands, and Pulau Ubin island. Granite makes up the bulk of the igneous rock. Gabbro is also found in the area and is found in an area called Little Guilin, named for its resemblance to Guilin in South China. This area is in Bukit Gombak. Sedimentary rocks are found on the western part of Singapore, which is mainly made of sandstone and mudstones. It also includes the southwestern area. Metamorphic rocks are found in the northeastern part of Singapore, and also on Pulau Tekong, off the east coast of Singapore. The rocks are mainly made up of quartzite, and also make up the Sajahat Formation.

Monte Muambe is volcanic caldera located south-east of Moatize in Tete Province of Mozambique

Iron-rich sedimentary rocks

Iron-rich sedimentary rocks are sedimentary rocks which contain 15% or more iron. However, most sedimentary rocks contain iron in varying degrees. The majority of these rocks were deposited during specific geologic time periods: The Precambrian, the early Paleozoic, and the middle to late Mesozoic. Overall, they make up a very small portion of the total sedimentary record.

Jordan Formation rock formation

The Jordan Formation is a siliciclastic sedimentary rock unit identified in Illinois, Michigan, Wisconsin, Minnesota, and Iowa. Named for distinctive outcrops in the Minnesota River Valley near the town of Jordan, it extends throughout the Iowa Shelf and eastward over the Wisconsin Arch and Lincoln anticline into the Michigan Basin.