Portal de Periódicos da CAPES

Brachiopod zonation in the late Paleozoic sequences of Argentina and its correlation with other South American basins

2022; Elsevier BV; Volume: 117; Linguagem: Inglês

10.1016/j.jsames.2022.103845

1873-0647

Gabriela A. Cisterna, Andrea F. Sterren,

Evolution and Paleontology Studies

South America late Paleozoic brachiopod biostratigraphy is herein revised considering the recent taxonomic updates, time-sensitive fossils associated and the radiometric data available in order to provide a tentative biostratigraphic scheme. Six zones are recognized in West and East-central Argentina, namely Azurduya chavelensis (Tournaisian-early Viséan), that contains the brachiopod fauna of Michiganites scalabrinii-Azurduya chavelensis Zone, restricted to the Río Blanco Basin and also identified in northern Chile; Levipustula levis (late Serpukhovian-Bashkirian), in the Calingasta-Uspallata Basin, typically associated with the postglacial transgression of the most widespread episode in the region, and also recorded from the Bolivian Tarija Basin; Marginovatia peregrina-Maemia tenuiscostata (late Bashkirian-early Moscovian), a zone of local value defined in the Barreal Hill of the Calingasta-Uspallata basin; Tivertonia jachalensis-Streptorhynchus inaequiornatus (Moscovian-early Kasimovian?), the most widely distributed and diversified in the Precordillera, developed in relatively warm temperate conditions; and the youngest Costatumlulus amosi (late Sakmarian-early Artinskian), a low-diversity brachiopod assemblage only recorded in the southernmost part the Calingasta-Uspallata Basin; to east, in the Sauce Grande Basin, Tomiopsis harringtoni Zone (Sakmarian-Artinskian) that includes the brachiopod assemblages of the Eurydesma Fauna also identified in the Paraná Basin, Brazil (Eurydesma-Lyonia Fauna herein referred to the informal Tomiopsis-Lyonia assemblage). A posglacial brachiopod assemblage, the Aseptella-Tuberculatella/Rhipidomella-Micraphelia Fauna (late Serpukhovian-Bashkirian), relatively coeval with the Levipustula levis Zone and compositional different, is also recognized in the Calingasta-Uspallata Basin. Late Paleozoic brachiopod faunas from Patagonia associated with a late Tournaisian-Artinskian glacial sequence would not have a biostratigraphic relationship with those of west-central Argentina. A few informal brachiopod assemblages, mainly dated by fusulinids and conodonts, are herein proposed for the other South American basins. These assemblages are Tapajotia tapajotensis-Rhipidomella penniana (late Serpukhovian) in the Amazon Basin (Brazil), and also recongnized in the Moscovian of the Madre de Dios Basin (Perú); Amazonoproductus amazonensis-Anthracospirifer oliveirai (Bashkirian) in the Amazon Basin; Gypospirifer condor-Linoproductus cora (Moscovian-Sakmarian), in the Madre de Dios (Bolivia and Perú) and Navidad-Arizaro basins (Chile-Argentina), within which the species Waagenoconcha humboldti-Kochiproductus peruvianus are dominant to the Cisuralian; Alispirifer assemblage (late Bashkirian-Moscovian), in the Central Cordillera of Colombia); and the "Tethyan brachiopod assemblages" (late Pennsylvanian-Cisuralian), in the De Los Llanos Basin (Colombia and Venezuela).