Hard, fine-grained sedimentary rock composed of cryptocrystalline silica
For the Spanish municipality, see Xert.
Chert
Sedimentary rock
A hand sample of chert
Composition
Microcrystalline or cryptocrystalline quartz
Chert (/ˈtʃɜːrt/) is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz,[1] the mineral form of silicon dioxide (SiO2).[2] Chert is characteristically of biological origin, but may also occur inorganically as a chemical precipitate or a diagenetic replacement, as in petrified wood.[3]
Chert is typically composed of the petrified remains of siliceous ooze, the biogenic sediment that covers large areas of the deep ocean floor, and which contains the silicon skeletal remains of diatoms, silicoflagellates, and radiolarians.[4] Precambrian cherts are notable for the presence of fossil cyanobacteria.[5] In addition to microfossils,[4] chert occasionally contains macrofossils.[6][7] However, some chert is devoid of any fossils.[8]
Chert varies greatly in color, from white to black, but is most often found as gray, brown, grayish brown and light green to rusty red[9][10] and occasionally as dark green.[11] Its color is an expression of trace elements present in the rock. Both red and green are most often related to traces of iron in its oxidized and reduced forms, respectively.[4][12]
^Knauth, L. Paul (1 June 1979). "A model for the origin of chert in limestone". Geology. 7 (6): 274–77. Bibcode:1979Geo.....7..274K. doi:10.1130/0091-7613(1979)7<274:AMFTOO>2.0.CO;2.
^"Chert: Sedimentary Rock - Pictures, Definition, Formation". geology.com. Retrieved 12 May 2018.
^Bates, R. L.; Jackson, J., eds. (1984). Dictionary of Geological Terms (3rd ed.). American Geological Institute/Doubleday. p. 85. ISBN 0385181019. OCLC 465393210.
^ abcBoggs, Sam (2006). Principles of sedimentology and stratigraphy (4th ed.). Upper Saddle River, New Jersey: Pearson Prentice Hall. pp. 208–10. ISBN 0131547283.
^Golubic, Stjepko; Seong-Joo, Lee (October 1999). "Early cyanobacterial fossil record: preservation, palaeoenvironments and identification". European Journal of Phycology. 34 (4): 339–48. Bibcode:1999EJPhy..34..339G. doi:10.1080/09670269910001736402.
^Bonde, Suresh D.; Kumaran, K. P. N. (February 2002). "The oldest macrofossil record of the mangrove fern Acrostichum L. from the Late Cretaceous Deccan Intertrappean beds of India". Cretaceous Research. 23 (1): 149–52. Bibcode:2002CrRes..23..149B. doi:10.1006/cres.2001.0307.
^Kotyk, M. E.; Basinger, J. F.; Gensel, P. G.; de Freitas, T. A. (1 June 2002). "Morphologically complex plant macrofossils from the Late Silurian of Arctic Canada". American Journal of Botany. 89 (6): 1004–13. doi:10.3732/ajb.89.6.1004. PMID 21665700.
^Boggs 2006, p. 207.
^W.L. Roberts, T.J. Campbell, G.R. Rapp Jr., "Encyclopedia of Mineralogy, Second Edition", 1990. ISBN 0-442-27681-8
^R.S. Mitchell, "Dictionary of Rocks", 1985. ISBN 0-442-26328-7
^McBride, E.F.; Folk, R.L. (1977). "The Caballos Novaculite Revisited: Part II: Chert and Shale Members and Synthesis". SEPM Journal of Sedimentary Research. 47. doi:10.1306/212F731A-2B24-11D7-8648000102C1865D.
^Thurston, Diana R. (1972). "Studies on bedded cherts". Contributions to Mineralogy and Petrology. 36 (4): 329–334. Bibcode:1972CoMP...36..329T. doi:10.1007/BF00444339. S2CID 128745664.
Chert (/ˈtʃɜːrt/) is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide...
The Princeton Chert is a fossil locality in British Columbia, Canada, which comprises an anatomically preserved flora of Eocene Epoch age, with rich species...
is made up of three formations, the Grassy Knob Chert, the Backbone Limestone and Clear Creek Chert. It is Lower Devonian in age. Eastward the group...
microorganisms permineralized in 3.465-billion-year-old Australian Apex chert rocks. However, the evidence for the biogenicity of these microstructures...
The Gunflint chert (1.88 Ga) is a sequence of banded iron formation rocks that are exposed in the Gunflint Range of northern Minnesota and northwestern...
white chert. Facies 3, which overlies facies 2, consists largely of centimeter-layered chert. The layered chert consists of white-gray layered chert and...
The Bigfork Chert is a Middle to Late Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. First described in 1892, this...
Clifty Limestone is very sandy, light blue to bluish grey. The Penters Chert is a Devonian geologic formation in the Ozark Plateaus of Arkansas. Its...
and William H. Lang in 1917. The species is known only from the Rhynie chert in Aberdeenshire, Scotland, where it grew in the vicinity of a silica-rich...
Mill Creek chert is a type of chert found in Southern Illinois and heavily exploited by members of the Mississippian culture (800 to 1600 CE). Artifacts...
partial head with preserved mouthparts from the Early Devonian aged Rhynie chert around 400 million years ago, when Earth’s first terrestrial ecosystems...
The Huntersville Chert or Huntersville Formation is a Devonian geologic formation in the Appalachian region of the United States. It is primarily composed...
Radiolarite is a siliceous, comparatively hard, fine-grained, chert-like, and homogeneous sedimentary rock that is composed predominantly of the microscopic...
experienced low-grade metamorphism. Other important lithologies include chert, basalt, limestone, serpentinite, and high-pressure, low-temperature metabasites...
surfaces of the chert, totally weathered out of the chert, and as hollow chert casts of the acorns. A total of 42 specimens in chert were studied by paleobotanists...
Devonian fossil assemblage from the Rhynie chert. These early plants were preserved by being petrified in chert formed in silica-rich volcanic hot springs...
Oxidation Event or snowball earths. The red bands are microcrystalline red chert, also called jasper. Picture jaspers exhibit combinations of patterns resulting...
cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely...
In 2014, a chert manuport was discovered embedded in an ancient reef on Barrow Island, Western Australia. The island has no natural chert deposits and...
kilometres (23–36 mi) wide, collided with the Earth. The Buck Reef chert and the Josefsdal chert, two rock formations in the Barberton Greenstone Belt, both...
Early Eocene Princeton Chert in British Columbia, Canada. Allenbya collinsonae is known exclusively from the Princeton Chert, a fossil locality in British...
a part of the fold belt. Rocks are turbidites, block in matrix mélange, chert, and volcanics. The accretionary complex itself could either be the toe...
The Nuvvuagittuq Greenstone Belt (NGB; Inuktitut: [nuv.vu.a.git.tuq]) is a sequence of metamorphosed mafic to ultramafic volcanic and associated sedimentary...
from diatom-rich plankton, became diatomites, porcelainites, and banded cherts. The Monterey formation has long been recognized as the primary source of...
mainly of the Liminangcong Formation, a Permian to Late Jurassic chert. This chert forms the distinguishing mountain ranges, with the Middle-Late Jurassic...
Wellman, C. H. (2011). "A high-precision U–Pb age constraint on the Rhynie Chert Konservat-Lagerstätte: time scale and other implications". Journal of the...
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