| 词条 | Irati Formation | ||
| 释义 |
| name = Irati Formation | period = Early Permian | age = Early Permian ~{{fossil range|278.4|270}} | image = Parana Basin simplified stratigraphic chart.png | imagesize = | caption = The Irati Formation belongs to the Gondwana I megasequence | type = Geological formation | prilithology = Black shale | otherlithology = Sandstone | unitof = Passa Dios Group | subunits = | underlies = Serra Alta Formation (Paraná Basin) Teresina Formation (Pelotas Basin) | overlies = Palermo Formation | thickness = up to {{convert|80|m|ft|abbr=on}} | area = {{convert|1000000|km2|sqmi|abbr=on}} | map = South America satellite plane Bacia do Parana.jpg | map_caption = The Paraná Basin in South America | location | coordinates = {{coord|25.5|S|50.7|W|display=inline,title}} | region = Paraná & Pelotas Basins Goiás, Mato Grosso do Sul, Mato Grosso, São Paulo, Paraná, Santa Catarina, Rio Grande do Sul | country = {{BRA}} | extent = | namedfor = | namedby = White | year_ts = 1908 | location_ts = | coordinates_ts = | paleocoordinates_ts = {{coord|45.8|S|29.7|W|display=inline}} | region_ts = | country_ts = | thickness_ts = }}Irati Formation is the name of a geological formation of the Paraná Basin in Brazil. It has previously been dated as Late Permian using palynomorphs, but is now dated as Early Permian using zircon ages obtained from bentonite layers. The base of the formation has been dated at 278.4 ± 2.2 Ma.[1][2] Exposures of the Irati Formation are to be found in the South (Geopark of Paleorrota), southeastern Brazil and in the states of Goiás, Mato Grosso, São Paulo, Paraná, Santa Catarina, Rio Grande do Sul and Mato Grosso do Sul.[1] The formation is part of the Passa Dios Group, underlying the Serra Alta Formation and overlying the Palermo Formation. The formation has been deposited in a restricted marine environment.[3] The Irati Formation, with a maximum thickness of {{convert|80|m|ft}}, was defined and named by White in 1908.[4] Fossil contentThe formation is particularly famous for the occurrences of the mesosaurs Mesosaurus tenuidiens,[5] and Stereosternum tumidum. Other fossils found in the formation are Myelontordoxylon camposii,[6] and crustaceans of the genera Paulocaris, Pygaspis, Liocaris, and Clarkecaris.[7] It is considered time equivalent to the Whitehill Formation of the Ecca Group of the Karoo Supergroup of southern Africa and the Mangrullo Formation of Uruguay.[8] {{left|See also{{portal|Brazil|Geology|Paleontology|Permian|Prehistory of South America}}
References1. ^1 Da Costa, 2015, p.28 2. ^Ventura Santos et al., 2006 3. ^Diduch, 2011, p.21 4. ^Da Costa, 2015, p.12 5. ^Irati at Fossilworks.org 6. ^Diduch, 2011, p.24 7. ^Diduch, 2011, p.23 8. ^Piñeiro et al., 2012, p.299 Bibliography
17 : Geologic formations of Brazil|Paraná Basin|Permian System of South America|Cisuralian Series|Permian Brazil|Shale formations|Sandstone formations|Oil shale formations|Oil shale in Brazil|Paleozoic southern paleotemperate deposits|Geography of Goiás|Geography of Mato Grosso|Geography of Mato Grosso do Sul|Geography of Paraná (state)|Geography of Rio Grande do Sul|Geography of Santa Catarina (state)|Geography of São Paulo (state) |
||
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。