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

CISTERNA, G.A.; STERREN, A.F.

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2022 vol. 117

0895-9811

South America late Paleozoic brachiopod biostratigraphy is herein revised considering the recent taxonomicupdates, time-sensitive fossils associated and the radiometric data available in order to provide a tentativebiostratigraphic scheme. Six zones are recognized in West and East-central Argentina, namely Azurduya chavelensis(Tournaisian-early Vis´ean), that contains the brachiopod fauna of Michiganites scalabrinii-Azurduya chavelensisZone, restricted to the Río Blanco Basin and also identified in northern Chile; Levipustula levis (lateSerpukhovian-Bashkirian), in the Calingasta-Uspallata Basin, typically associated with the postglacial transgressionof the most widespread episode in the region, and also recorded from the Bolivian Tarija Basin; Marginovatiaperegrina-Maemia tenuiscostata (late Bashkirian-early Moscovian), a zone of local value defined in theBarreal Hill of the Calingasta-Uspallata basin; Tivertonia jachalensis-Streptorhynchus inaequiornatus (MoscovianearlyKasimovian?), the most widely distributed and diversified in the Precordillera, developed in relativelywarm temperate conditions; and the youngest Costatumlulus amosi (late Sakmarian-early Artinskian), a lowdiversitybrachiopod assemblage only recorded in the southernmost part the Calingasta-Uspallata Basin; toeast, in the Sauce Grande Basin, Tomiopsis harringtoni Zone (Sakmarian-Artinskian) that includes the brachiopodassemblages of the Eurydesma Fauna also identified in the Paran´a Basin, Brazil (Eurydesma-Lyonia Fauna hereinreferred to the informal Tomiopsis-Lyonia assemblage). A posglacial brachiopod assemblage, the Aseptella-Tuberculatella/Rhipidomella-Micraphelia Fauna (late Serpukhovian-Bashkirian), relatively coeval with the Levipustulalevis Zone and compositional different, is also recognized in the Calingasta-Uspallata Basin. Late Paleozoicbrachiopod faunas from Patagonia associated with a late Tournaisian-Artinskian glacial sequence would not havea 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 assemblagesare Tapajotia tapajotensis-Rhipidomella penniana (late Serpukhovian) in the Amazon Basin (Brazil), andalso 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 whichthe species Waagenoconcha humboldti-Kochiproductus peruvianus are dominant to the Cisuralian; Alispiriferassemblage (late Bashkirian-Moscovian), in the Central Cordillera of Colombia); and the “Tethyan brachiopodassemblages” (late Pennsylvanian-Cisuralian), in the De Los Llanos Basin (Colombia and Venezuela).