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Folk's carbonate rock classification details the relative proportions of allochems in the rock and the type of matrix. The classification scheme covers most common carbonate rocks, however the more inclusive although less precise alternative, Dunham classification, may be preferred in some instances. Folk classification consists of one or two ...
The Dunham classification system for carbonate sedimentary rocks was originally devised by Robert J. Dunham (1924–1994) [1] in 1962, [2] and subsequently modified by Embry and Klovan in 1971 [3] to include coarse-grained limestones and sediments that had been organically bound at the time of deposition.
Siliciclastic sedimentary rocks are then subcategorized based on their grain size distribution and the relative proportions of quartz, feldspar, and lithic (rock) fragments. [12] Carbonate rocks are classified with the Dunham or Folk classification schemes according to the constituents of the carbonate rock. [13]
Phosphorite – Sedimentary rock containing large amounts of phosphate minerals – A non-detrital sedimentary rock that contains high amounts of phosphate minerals; Sandstone – Type of sedimentary rock; Shale – Fine-grained, clastic sedimentary rock; Siltstone – Sedimentary rock which has a grain size in the silt range
A sequence of fossil-bearing sedimentary rocks can be subdivided on the basis of the occurrence of particular fossil taxa. A unit defined in this way is known as a biostratigraphic unit, generally shortened to biozone. [6] The five commonly used types of biozone are assemblage, range, abundance, interval and lineage zones. [7]
The identification is based on comparison of physical and mineralogical characteristics of the rocks, and on general assumptions known as the Steno's principles: [8] 1. The sedimentary strata occurred sequentially in time: the youngest at the top. 2. The strata are originally horizontal. 3.
Uluru (Ayers Rock) is a large sandstone formation in Northern Territory, Australia.. Sedimentary rocks can be subdivided into four groups based on the processes responsible for their formation: clastic sedimentary rocks, biochemical (biogenic) sedimentary rocks, chemical sedimentary rocks, and a fourth category for "other" sedimentary rocks formed by impacts, volcanism, and other minor processes.
Conglomerate (/ k ən ˈ ɡ l ɒ m ər ɪ t /) is a sedimentary rock made up of rounded gravel-sized pieces of rock surrounded by finer-grained sediments (such as sand, silt, or clay). The larger fragments within conglomerate are called clasts, while the finer sediment surrounding the clasts is called the matrix.