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Dunham Classification
The Dunham classification system for Carbonate minerals, carbonate sedimentary rocks was originally devised by Robert J. Dunham (1924–1994) in 1962, and subsequently modified by Embry and Klovan in 1971 to include coarse-grained limestones and sediments that had been organically bound at the time of Deposition (geology), deposition. The ''modified Dunham Classification'' has subsequently become the most widely employed system for the classification of carbonate sedimentary rocks with 89% of workers currently adopting this system over the alternative Folk classification, Folk classification scheme History Original classification Robert J. Dunham published his classification system for limestone in 1962. The original Dunham classification system was developed in order to provide convenient depositional-texture based class names that focus attention on the textural properties that are most significant for interpreting the depositional environment of the rocks. The three criteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wackestone
Under the Dunham classification (Dunham, 1962Dunham, R.J., 1962. Classification of carbonate rocks according to depositional texture. In: W.E. Ham (Ed.), Classification of Carbonate Rocks. American Association of Petroleum Geologists Memoir. American Association of Petroleum Geologists, Tulsa, Oklahoma, pp. 108–121.) system of limestones, a wackestone is defined as a mud-supported carbonate rock Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and Dolomite (rock), dolomite rock (also kn ... that contains greater than 10% grains. Most recently, this definition has been clarified as ''a carbonate-dominated rock in which the carbonate mud (2 mm)''. The identification of wackestone A study of the adoption and use of carbonate classification systems by Lokier and Al Junaibi (2016) highlighted that the most common problem enc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Rocks
Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedimentation is any process that causes these particles to settle in place. Geological detritus originates from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or mass movement, which are called agents of denudation. Biological detritus is formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies ( marine snow). Sedimentation may also occur when dissolved minerals precipitate from water solution. The sedimentary rock cover of the continents of the Earth's crust is extensive (73% of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Framestone
A framestone is a special type of carbonate rock in the Dunham classification The Dunham classification system for Carbonate minerals, carbonate sedimentary rocks was originally devised by Robert J. Dunham (1924–1994) in 1962, and subsequently modified by Embry and Klovan in 1971 to include coarse-grained limestones and .... Description The term "framestone" was not used in the original Dunham classification by Dunham (1962). It first appeared in the modified Dunham classification by Embry and Klovan (1971) where it is described as an autochthonous limestone having "in situ massive fossils which constructed a rigid three-dimensional framework during deposition. The in situ fossils therefore form the supporting framework of the rock, with matrix material occurring in the interstices between the fossils." Lokier and Al Junaibi(2016) define a framestone as "an autochthonous carbonate-dominated rock supported by a rigid organic framework developed at the time of deposition." ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bindstone
Bindstone is a special type of carbonate rock in the Dunham classification. The term did not appear in the original Dunham classification from 1962 and was introduced by Embry and Klovan 1971 in the modified Dunham classification. Description Embry and Klovan (1971) define bindstones as rocks that "[...] contain in situ, tabular or lamellar fossils which encrusted and bound sediment during deposition. [...] The matrix, not the in situ fossils, forms the supporting framework of the rock, and the fossils may form as little as 15 percent of the constituents of the rock." Wright (1991) uses bindstone as a synonym for boundstone, which is defined as a rock "[...] where the structure reflects the encrusting and binding action of plants or animals" Lokier and Al Nunaibi (2016) define bindstones as "autochthonous carbonate-dominated rock in which the original components of the supporting matrix were organically bound through stabilization of the sediment at the time of deposition." Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bafflestone
Bafflestone is a type of carbonate rock. The Dunham Classification (Dunham, 1962) of limestones employed the term boundstone to encompass all carbonate rocks that exhibited any evidence of the original components being organically-bound together at the time of deposition. Embry & Klovan (1971Embry, A.F. and Klovan, J.E. (1971) A Late Devonian reef tract on Northeastern Banks Island, NWT. Bull. Can. Pet. Geol., 19, 730–781.) proposed the sub-division of the boundstone classification in order to reflect the different mechanisms of binding within these autochthonous carbonate sediments. The classification ''bafflestone'' was proposed to describe sediments that formed where organic baffling resulted in a reduction in flow and a consequent deposition of suspended material. However, even at the time of introducing the new classification, Embry & Klovan (1971), noted that the class ''bafflestone'' was highly-interpretive and, the mechanism of formation was difficult to prove requiring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudstone
Rudstone is a type of carbonate rock. The Dunham classification (Dunham, 1962) did not consider grain size as a criterion for the description of carbonate lithologies. In an attempt to rectify this perceived deficiency, Embry & Klovan (1971) introduced the terms ''rudstone'' (grain supported) and '' floatstone'' (matrix supported) for coarse-grained allochthonous River ecosystems are flowing waters that drain the landscape, and include the biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its many parts.Angelier ... carbonates. Following a survey of the use of the Dunham classification, Lokier and Al Junaibi (2016) clarified the definition of a rudstone as "''a carbonate-dominated rock where more than 10% of the volume is grains larger than 2 mm and these grains support the fabric of the rock."'' References {{Dunham classification rocks Limestone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floatstone
Floatstone is a type of carbonate rock. The original Dunham classification (Dunham, 1962) of limestones did not consider the separate classification of coarse grained carbonate lithologies. In an attempt to rectify this, Embry & Klovan (1971Embry, A.F. and Klovan, J.E. (1971) A Late Devonian reef tract on Northeastern Banks Island, NWT. Bull. Can. Pet. Geol., 19, 730–781.) introduced the terms rudstone (grain supported) and floatstone (matrix supported) for coarse-grained allochthonous limestones. This definition of a floatstone was most recently clarified as "a carbonate-dominated rock where more than 10% of the volume is grains larger than 2 mm and the fabric is supported by the component that is 2 mm and smaller". References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
