| 词条 | Guabirotuba Formation | |||||||||||||||||||||||||||||||||||||||||||||||
| 释义 |
| name = Guabirotuba Formation | image = | caption = | type = Geological formation | period = Bartonian | age = Late Mid Eocene (Divisaderan) ~{{fossil range|42|38}} | prilithology = Mudstone, sandstone | otherlithology = Conglomerate | namedfor = Guabirotuba, Curitiba | namedby = Salamuni & Bigarella | year_ts = 1962 | region = Paraná | country = {{BRA}} | coordinates = {{coord|25.5|S|49.3|W|display=inline,title}} | paleocoordinates = {{coord|27.5|S|39.8|W|display=inline}} | unitof = | subunits = | underlies = alluvium | overlies = Cambrian basement | thickness = {{convert|60|-|80|m|ft|abbr=on}} | extent = Curitiba Basin | area = | map = {{Location map+ | Brazil | relief = 1 | width = 250 | float = center | places = | lat_deg = -25.5 | lon_deg = -49.3 | mark = Orange pog.svg | marksize = 12 }} | map_caption = }} The Guabirotuba Formation is a late Middle Eocene (Divisaderan in the SALMA classification) geologic formation of the Curitiba Basin in Paraná, Brazil. The formation crops out in and around the city of Curitiba and comprises mudstones and sandstones deposited in a fluvial floodplain environment. The {{convert|60|to|80|m|ft}} thick formation has provided several fossil mammals, and indeterminate side-neck turtle fossils, and indeterminate terror bird fossils. A newly described species of Cingulata; Proeocoleophorus carlinii was also found in the formation. DescriptionThe Guabirotuba Formation was first described by {{ill|Riad Salamuni|pt}} and {{ill|João José Bigarella|pt}} in 1962. The geologists named the formation after {{ill|Guabirotuba|pt}}, a neighborhood of Curitiba, the capital of Paraná State.[1] The formation is the lowermost sedimentary unit in the {{convert|3000|km2|sqmi}} Curitiba Basin, a Cenozoic continental rift basin of southeastern Brazil,[2] overlying Cambrian basement comprising gneisses, amphibolites and migmatites of the Atuba Complex and metasediments of the Açungui Group.[3][4] LithologiesThe {{convert|60|to|80|m|ft}} thick Guabirotuba Formation comprises a basal conglomerate,[5] mudstones and sandstones,[3] deposited in a fluvial floodplain environment.[2][6] The sediments of the formation contain between 0.24 and 2.61% heavy minerals.[7] Heavy mineral analysis on the very abundant zircons, abundant epidote, common tourmaline and kyanite and rare rutile has provided insight in the paleocurrents of the fluvial environment, with predominant flow directions towards the northwest and east-northeast.[8] {{clearleft}}AgeThe age of the formation has been a matter of debate, with early descriptions assigning the formation to the Miocene to Pliocene,[6] but after the discovery of a mammal fauna described by Sedor et al. in 2017, the age of the formation has been defined as late Middle Eocene, or "Barrancan", which is a sub-age of the Divisaderan South American land mammal age,{{refn|group=note|The sub-ages "Barrancan" and "Vacan" are based on respectively the Gran Barranca Member and the Cañadón Vaca section of the Sarmiento Formation in Patagonia, Argentina and are not formally established;[9] some authors consider the "Barrancan" as the upper age of the Casamayoran[13]}} ranging from approximately 42 to 39 Ma.[10][11] Paleontological significanceThe Guabirotuba Formation is one of few formations in Brazil providing Paleogene mammal faunas, between the older Tiupampan Maria Farinha Formation of the Parnaíba Basin and the Itaboraian Itaboraí Formation of the Itaboraí Basin in Rio de Janeiro State, and the younger Tinguirirican Entre-Córregos Formation of the Aiuruoca Basin and the Deseadan Tremembé Formation of the Taubaté Basin.[2] Fossil contentFossils recovered from the formation include:[12]
See also{{Portal|Geology|Paleontology|Paleogene|Prehistory of South America}}
Notes and referencesNotes1. ^Monteiro Machado, 2012, p.564 2. ^1 2 Sedor et al., 2017, p.39 3. ^1 Da Silva Felipe, 2011, p.12 4. ^Monteiro Machado, 2012, p.565 5. ^Da Silva Felipe, 2011, p.17 6. ^1 Monteiro Machado, 2012, p.566 7. ^Monteiro Machado, 2012, p.567 8. ^Monteiro Machado, 2012, p.570 9. ^Woodburne et al., 2014, p.19 10. ^1 Bellosi & Krause, 2014, p.31 11. ^Woodburne et al., 2014, p.7 12. ^1 2 3 4 5 6 7 8 9 10 11 12 13 Guabirotuba Fauna at Fossilworks.org 13. ^Sedor et al., 2014, p.807 14. ^Wagner Rogério et al., 2012, p.44 References{{reflist|30em}}Bibliography
13 : Geologic formations of Brazil|Eocene Series of South America|Paleogene Brazil|Bartonian|Divisaderan|Mudstone formations|Sandstone formations|Conglomerate formations|Fluvial deposits|Fossiliferous stratigraphic units of South America|Paleontology in Brazil|Geography of Paraná (state)|Tupi–Guarani languages |
|||||||||||||||||||||||||||||||||||||||||||||||
| 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。