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Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g., kaolin, Al 2 Si 2 O 5 4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite. [1]
The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. [ 2 ] [ 3 ] It is famous for the exceptional preservation of the soft parts of its fossils. At 508 million years old ( middle Cambrian ), [ 4 ] it is one of the earliest fossil beds containing soft-part imprints.
The black shales of the Kettle Point Formation are organic-rich and highly fissile. Some layer of black shale are interlaminated with white-coloured laminae of clay- to silt-sized quartz and calcite grains. The associated greyish green mudstones are homogeneous, lacking discernible lamination or other primary sedimentary structures.
The Marcellus Formation or the Marcellus Shale is a Middle Devonian age unit of sedimentary rock found in eastern North America.Named for a distinctive outcrop near the village of Marcellus, New York, in the United States, [3] it extends throughout much of the Appalachian Basin.
The upper part of the Cleveland Shale is a black to brownish black [13] silty shale [9] with occasional thin beds of gray shale and siltstone. [5] The upper part is much richer in petroleum [16] and kerogen. [4] [d] When broken open, fresh samples smell like crude oil. [4]
The Ready Pay Member (formerly lower Percha) is mostly black fissile shale nearly devoid of fossils and with a total thickness of about 132 feet (40 m). [1] The Box Member (formerly upper Percha), which is much less limited in areal extent, [3] is about 47 feet (14 m) of gray to green calcareous shale with limestone nodules and beds. It is ...
Black shale is one of the preliminary indicators of anoxia and perhaps euxinia. Black shales are organic rich, microlaminated sedimentary rocks often associated with bottom water anoxia. [18] This is because anoxia slows the degradation of organic matter, allowing for greater burial in the sediments.
[19] [18] The Thermopolis Shale was the basal of four formations making up the Colorado Group. He described the Thermopolis Shale as Late Cretaceous in age, [19] [18] generally dark in color, from 710 feet (220 m) thick, and with sandstone lenses common. At least one member of the Thermopolis Shale was also noted, a "muddy sand" layer about 15 ...