Carboniferous deposits of northern Sierra de Tecka, central-western Patagonia, Argentina: paleontology, biostratigraphy and correlations

TABOADA, ARTURO CESAR; PAGANI, MARÍA ALEJANDRA; PINILLA, MARÍA KARINA; TORTELLO, FRANCO; TABOADA, CÉSAR AUGUSTO

ANDEAN GEOLOGY

SERVICIO NACIONAL GEOLOGIA MINERVA

Año: 2019 vol. 46 p. 629 - 669

0718-7092

A narrow upper Paleozoic belt crops out in the northern tip of Sierra de Tecka through the Quebradade Güera-Peña (Patagonia, Argentina). There, black shales of the Pampa de Tepuel Formation contain marine fossil invertebrates previously listed as belonging to the ?Levipustula? fauna. Material recently recorded by the authors comprises, in order of abundance, gastropods [Glabrocingulum (Glabrocingulum) poperimense (Maxwell), G. (Stenozone) argentinum (Reed), G. (Stenozone) sp., Peruvispira teckaensis sp. nov., Ananias riccardii Pinilla], bivalves[Nuculopsis (Nuculopsis) patagoniensis González, Phestia tepuelensis González, Streblochondria sueroi González, Streblopteria sp.], conulariids [Paraconularia cf. ugartei Cúneo and Sabattini], brachiopods [Amosia sueroi Simanauskas,Languigneotus laevicaudatum (Amos), Beecheria patagonica Amos], trilobites [Australosutura argentinensis Hahn and Hahn], cephalopods [Pseudoorthoceratidae Flower and Caster, Sueroceras? sp., Mitorthoceras? sp.], and rugose corals[?Lophophyllidiidae Moore and Jeffords]. In addition, the present study includes the new key brachiopods Languigneotus dammanorum gen. et sp. nov. and Tuberculatella waterhousei sp. nov. from younger localities of the Tepuel-Genoa Basin. The Languigneotus laevicaudatum and Languigneotus-Verchojania subzones (late Pennsylvanian) are proposed hereinto replace the former Tuberculatella Zone. In addition, previous stratigraphic relationships and correlations of the studysection with the Arroyo Pescado (Estancia Ap Iwan) and Esquel areas are discussed. The general stratigraphic profile ofa glacial-related section cropping out at Estancia Ap Iwan includes lower conglomeradic beds, which are reinterpretedas early Jurassic in age, and glacimarine levels that are partially equivalent to the Pampa de Tepuel Formation but olderthan those of Quebrada de Güera-Peña. A correlation of the Esquel Formation with the Arroyo Pescado Formation andother contemporaneous units on the paleopacific margin is assessed, implying that the Esquel Formation should be segregated from the Tepuel Group. The Esquel and Arroyo Pescado formations can be regarded as the basement of theglaciomarine column of the Tepuel-Genoa Basin.