Two types of sedimentary rock: limey shale overlain by limestone. Shale (also called mudstone) is a fine-grained Sedimentary rock whose original constituents were Clay minerals or Muds It is characterized by Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Cumberland Plateau, Tennessee

Sedimentary rock is one of the three main rock groups (the others being igneous and metamorphic rock). The Cumberland Plateau is the southern part of the Appalachian Plateau. Tennessee ( is a state located in the Southern United States. In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change Rock formed from sediments covers 75-80% of the Earth's land area, and includes common types such as chalk, limestone, dolomite, sandstone, conglomerate and shale. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of Chalk (ʧɔːk is a soft white porous Sedimentary rock, a form of Limestone composed of the Mineral Calcite. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Dolomite (ˈdɒləmaɪt is the name of a Sedimentary Carbonate rock and a Mineral, both composed Sandstone is a Sedimentary rock composed mainly of Sand -size Mineral or rock grains. A conglomerate (kɒnˈglɒmərət is a rock consisting of individual stones that have become cemented together Shale (also called mudstone) is a fine-grained Sedimentary rock whose original constituents were Clay minerals or Muds It is characterized by ^[1]

Sedimentary rocks are classified by the source of their sediments, and are produced by one or more of:

• clastic rock formed from fragments broken off from parent rock, by
  • weathering in situ or
  • erosion by water, ice or wind, followed by transportation of sediments, often in suspension, to the place of deposition;
• biogenic activity; or
• precipitation from solution. Clastic rocks are composed of fragments or clasts, of pre-existing rock. Weathering is the decomposition of earth rocks, Soils and their Minerals through direct contact with the planet's Atmosphere. Erosion is the carrying away or displacement of solids ( Sediment, Soil, rock and other particles usually by the agents of currents such as wind In geology transportation refers to the movement of eroded debris whether by Rivers Glaciers Wind or Ocean currents and In Chemistry, A suspension is a Heterogenous fluid containing Solid particles that are sufficiently large for Sedimentation. Deposition is the geological process by which material is added to a Landform or land mass A biogenic substance is a substance produced by Life processes Precipitation is the formation of a Solid in a Solution during a Chemical reaction. In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances

The sediments are then compacted and converted to rock by the process of lithification. Compaction (geology refers to the process by which a Sediment progressively loses its Porosity due to the effects of loading Lithification (from the Greek word lithos meaning 'rock' and the Latin -derived suffix -ific) is the process in which Sediments compact

Formation

Sedimentary-rock formation, Karnataka, India

Sedimentary rocks are formed because of the overburden pressure as particles of sediment are deposited out of air, ice, wind, gravity, or water flows carrying the particles in suspension. Karnataka (ಕರ್ನಾಟಕ pronounced) is a state in the southern part of India India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Overburden pressure, lithostatic pressure, and vertical stress are terms that denote the Pressure or stress imposed on a layer of Soil Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of Settling is the process by which particulates settle to the bottom of a liquid and form a Sediment. In Chemistry, A suspension is a Heterogenous fluid containing Solid particles that are sufficiently large for Sedimentation. As sediment deposition builds up, the overburden (or 'lithostatic') pressure squeezes the sediment into layered solids in a process known as lithification ('rock formation') and the original connate fluids are expelled. Lithification (from the Greek word lithos meaning 'rock' and the Latin -derived suffix -ific) is the process in which Sediments compact The term connate fluids in the context of Geology, and of Sedimentology in particular refers to the liquids that were trapped in the pores of Sedimentary rocks The term diagenesis is used to describe all the chemical, physical, and biological changes, including cementation, undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface weathering. In Geology and Oceanography, diagenesis is any chemical physical or biological change undergone by a Sediment after its initial deposition and during

Sedimentary rocks are laid down in layers called beds or strata. That new rock layers are above older rock layers is stated in the principle of superposition. The law of superposition (or the principle of superposition) is a key axiom based on observations of Natural history that is a foundational principle of sedimentary There are usually some gaps in the sequence called unconformities. An unconformity is a buried Erosion surface separating two rock masses or strata of different ages indicating that Sediment deposition was not These represent periods in which no new sediments were being laid down, or when earlier sedimentary layers were raised above sea level and eroded away.

Sedimentary rocks contain important information about the history of Earth. The history of Earth covers approximately 46 billion years (4567000000 years from Earth ’s formation out of the Solar nebula to the present They contain fossils, the preserved remains of ancient plants and animals. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. Plants are living Organisms belonging to the kingdom Plantae. Coal is considered a type of sedimentary rock. The composition of sediments provides us with clues as to the original rock. Differences between successive layers indicate changes to the environment which have occurred over time. Sedimentary rocks can contain fossils because, unlike most igneous and metamorphic rocks, they form at temperatures and pressures that do not destroy fossil remains.

The sedimentary rock cover of the continents of the Earth's crust is extensive, but the total contribution of sedimentary rocks is estimated to be only 5% of the total. In Geology, a crust is the outermost solid shell of a planet or moon As such, the sedimentary sequences we see represent only a thin veneer over a crust consisting mainly of igneous and metamorphic rocks.

Classification

Sedimentary rocks are classified into three groups. These groups are clastic, chemical precipitate and biochemical or biogenic.

Clastic

Clastic sedimentary rocks are composed of discrete fragments or clasts of materials derived from other rocks. They are composed largely of quartz with other common minerals including feldspar, amphiboles, clay minerals, and sometimes more exotic igneous and metamorphic minerals. Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in Feldspar is the name of a group of rock-forming Minerals which make up as much as 60% of the Earth 's crust. Amphibole (pronounced amfi-bowl defines an important group of generally dark-colored rock-forming inosilicate Minerals composed of double chain SiO4 Clay minerals are hydrous Aluminium phyllosilicates, sometimes with variable amounts of Iron, Magnesium, Alkali metals Alkaline Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change

Clastic sedimentary rocks, such as breccia or sandstone, were formed from rocks that have been broken down into fragments by weathering, which then have been transported and deposited elsewhere.

Clastic sedimentary rocks may be regarded as falling along a scale of grain size, with shale being the finest with particles less than 0. Clastic rocks are composed of fragments or clasts, of pre-existing rock. Shale (also called mudstone) is a fine-grained Sedimentary rock whose original constituents were Clay minerals or Muds It is characterized by 002 mm, siltstone being a little bigger with particles between 0. Siltstone is a Sedimentary rock which has a composition intermediate in grain size between the coarser Sandstones and the finer Mudstones and 002 to 0. 063 mm, and sandstone being coarser still with grains 0. Sandstone is a Sedimentary rock composed mainly of Sand -size Mineral or rock grains. 063 to 2 mm, and conglomerates and breccias being more coarse with grains 2 to 263 mm. A conglomerate (kɒnˈglɒmərət is a rock consisting of individual stones that have become cemented together Breccia (ˈbrɛtʃiə ˈbrɛʃiə breach is a rock composed of angular fragments of several Minerals or rocks in a matrix, that is a cementing material Breccia has sharper particles, while conglomerate is categorized by its rounded particles. Particles bigger than 263 mm are termed blocks (angular) or boulders (rounded). Lutite, Arenite and Rudite are general terms for sedimentary rock with clay/silt-, sand- or conglomerate/breccia-sized particles. Lutite is any sedimentary Clastic rock with clay or silt grain size less than 1/16 mm (0 Arenite ( Latin Arena, sand is a sedimentary Clastic rock with sand grain size between 0 Rudite is any sedimentary Clastic rock with a grain size exceeding 2 mm (0

The classification of clastic sedimentary rocks is complex because there are many variables involved. Particle size (both the average size and range of sizes of the particles), composition of the particles, the cement, and the matrix (the name given to the smaller particles present in the spaces between larger grains) must all be taken into consideration.

Shales, which consist mostly of clay minerals, are generally further classified on the basis of composition and bedding.

Coarser clastic sedimentary rocks are classified according to their particle size and composition. Orthoquartzite is a very pure quartz sandstone; arkose is a sandstone with quartz and abundant feldspar; greywacke is a sandstone with quartz, clay, feldspar, and metamorphic rock fragments present, which was formed from the sediments carried by turbidity currents. Arkose (ˈɑrkoʊz is a Detrital Sedimentary rock, specifically a type of Sandstone containing at least 25% Feldspar. Greywacke ( German grauwacke, signifying a grey earthy rock is a variety of Sandstone generally characterized by its hardness dark color and poorly-sorted

All rocks disintegrate when exposed to mechanical and chemical weathering at the Earth's surface. Weathering is the decomposition of earth rocks, Soils and their Minerals through direct contact with the planet's Atmosphere.

Lower Antelope Canyon was carved out of the surrounding sandstone by both mechanical weathering and chemical weathering. Antelope Canyon is the most-visited and most-photographed Slot canyon in the American Southwest. Sandstone is a Sedimentary rock composed mainly of Sand -size Mineral or rock grains. Wind, sand, and water from flash flooding are the primary weathering agents. A flash flood is a rapid flooding of geomorphic lowlying areas - washes rivers and streams

Mechanical weathering is the breakdown of rock into particles without producing changes in the chemical composition of the minerals in the rock. Ice is the most important agent of mechanical weathering. Water percolates into cracks and fissures within the rock, freezes, and expands. The force exerted by the expansion is sufficient to widen cracks and break off pieces of rock. Heating and cooling of the rock, and the resulting expansion and contraction, also aids the process. Mechanical weathering contributes further to the breakdown of rock by increasing the surface area exposed to chemical agents.

Chemical weathering is the breakdown of rock by chemical reaction. In this process the minerals within the rock are changed into particles that can be easily carried away. Air and water are both involved in many complex chemical reactions. The minerals in igneous rocks may be unstable under normal atmospheric conditions, those formed at higher temperatures being more readily attacked than those which formed at lower temperatures. Igneous rocks are commonly attacked by water, particularly acid or alkaline solutions, and all of the common igneous rock forming minerals (with the exception of quartz which is very resistant) are changed in this way into clay minerals and chemicals in solution.

Rock particles in the form of clay, silt, sand, and gravel, are transported by the agents of erosion (usually water, and less frequently by ice and wind) to new locations and redeposited in layers, generally at a lower elevation.

These agents reduce the size of the particles, sort them by size, and then deposit them in new locations. The sediments dropped by streams and rivers form alluvial fans, flood plains, deltas, and on the bottom of lakes and the sea floor. The wind may move large amounts of sand and other smaller particles. Glaciers transport and deposit great quantities of usually unsorted rock material as till. Till is unsorted glacial sediment Glacial drift is a general term for the coarsely graded and extremely heterogeneous Sediments of glacial origin

These deposited particles eventually become compacted and cemented together, forming clastic sedimentary rocks. Such rocks contain inert minerals which are resistant to mechanical and chemical breakdown such as quartz, zircon, rutile, and magnetite. Zircon is a Mineral belonging to the group of nesosilicates. Its chemical name is Zirconium silicate and its corresponding chemical formula is Rutile is a Mineral composed primarily of Titanium dioxide, Ti[[oxygen O]]2 Magnetite is not to be confused with Magnesite or Maghemite. Magnetite is a ferrimagnetic Mineral with chemical Quartz is one of the most mechanically and chemically resistant minerals.

Organic

Outcrop of Ordovician oil shale (kukersite), northern Estonia. The Ordovician is a geologic period and system, the second of six of the Paleozoic era, and covers the time between 488 Kukersite is a marine type Oil shale of Ordovician age found in the Baltic Oil Shale Basin in Estonia and North-West Russia

Organic sedimentary rocks contain materials generated by living organisms, and include carbonate minerals created by organisms, such as corals, mollusks, and foraminifera, which cover the ocean floor with layers of calcite which can later form limestone. Corals are Marine organisms from the class Anthozoa and exist as small Sea anemone –like Polyps typically in colonies of many Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000 The Foraminifera, ("Hole Bearers" or forams for short are a large group of Amoeboid Protists with reticulating Pseudopods fine "Ocean Floor" redirects here For the 2001 song by Audio Adrenaline, see Lift (Audio Adrenaline album. Calcite is a carbonate mineral and the most stable polymorph of Calcium carbonate ( Ca[[carbon C]] O 3 Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Other examples include stromatolites, the flint nodules found in chalk (which is itself a biochemical sedimentary rock, a form of limestone), and coal and oil shale (derived from the remains of tropical plants and subjected to pressure). Stromatolites (from Greek στρώμα strōma, mattress bed stratum and λιθος lithos, rock are layered accretionary Structures formed in Flint (or flintstone) is a hard sedimentary Cryptocrystalline form of the Mineral Quartz, categorized as a variety of Chert Chalk (ʧɔːk is a soft white porous Sedimentary rock, a form of Limestone composed of the Mineral Calcite.

Chemical

Chemical sedimentary rocks form when mineral solutions, such as sea water, evaporate. Seawater is Water from a Sea or Ocean. On average seawater in the world's oceans has a Salinity of about 3 Examples include the evaporite minerals halite (rock salt) and gypsum. Evaporites (iˈvæpəraɪt are water-soluble Mineral sediments that result from the Evaporation of bodies of surficial Water. Halite is the Mineral form of Sodium chloride, Na[[chlorine Cl]] commonly known as rock salt. Gypsum is a very soft Mineral composed of Calcium sulfate dihydrate with the Chemical formula Ca[[sulfur S]] O 4·2

Economic and scientific relevance

Sedimentary rocks are economically important in that they can easily be used as construction material because they are soft and easy to cut. For example, the White House in Washington DC is made of sandstone. In addition, sedimentary rocks often form porous and permeable reservoirs in sedimentary basins in which petroleum and other hydrocarbons can be found (see Bituminous rocks). Porosity is a measure of the void spaces in a material and is measured as a fraction between 0–1 or as a Percentage between 0–100% Permeability in the Earth sciences (commonly symbolized as κ, or k) is a measure of the ability of a material (typically a rock or unconsolidated The term sedimentary basin is used to refer to any geographical feature exhibiting Subsidence and consequent infilling by sedimentation Petroleum ( L petroleum, from Greek πετρέλαιον, lit In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. Bituminous rocks are Sedimentary rocks, usually Shale, Sandstone, Limestone or Dolostone / Dolomite, that contain traces

It is believed that the relatively low levels of carbon dioxide in the Earth's atmosphere, in comparison to that of Venus, is because of large amounts of carbon being trapped in limestone and dolomite sedimentary layers. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five The VENUS ( V ictoria E xperimental N etwork U nder the S ea project is a cabled sea floor observatory operated by the University Dolomite (ˈdɒləmaɪt is the name of a Sedimentary Carbonate rock and a Mineral, both composed The flux of carbon from eroded sediments to marine deposits is part of the carbon cycle. The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the Biosphere, Pedosphere, Geosphere, Hydrosphere, and

The shape of the particles in sedimentary rocks has an important effect on the ability of micro-organisms to colonize them. A microorganism (also spelled micro organism or micro-organism and also called a microbe) is an Organism that is Microscopic (usually This interaction is studied in the science of geomicrobiology. Geomicrobiology is a subset of the scientific discipline Microbiology. One measure of the shape of these particles is the roundness factor, also known as the Krumbein number after the geologist W. C. Krumbein. William Christian Krumbein (1902-1979 was a notable geologist after whom the Krumbein Medal of the International Association for Mathematical Geology (IAMG was named

See also

• Back-stripping
• Deposition (sediment)
• List of minerals
• List of rock types
• Sediment
• Transportation (sediment)

Footnotes

References

• Blatt, Harvey and Robert James Tracy, 1994, Petrology: Igneous, Sedimentary and Metamorphic, Freeman, 2nd Ed. ISBN 0-7167-2438-3
• Folk, R. L. , 1965, Petrology of sedimentary rocks PDF version. Austin: Hemphill’s Bookstore. 2nd ed. 1981, ISBN 0-914696-14-9
• Basic Sedimentary Rock Classification