Glaciomarine sequence stratigraphy in the Mississippian Rio Blanco Basin, Argentina, southwestern Gondwana. Basin analysis and palaeoclimatic implications for the Late Paleozoic Ice Age during the Tournaisian.

Autor(es)

Ezpeleta, Miguel ^{[1, 2]} ; Jose Rustan, Juan ^{[1, 2]} ; Balseiro, Diego ^[1] ; Miguel Davila, Federico ^[1] ; Andres Dahlquist, Juan ^[1] ; Emilio Vaccari, Norberto ^{[1, 2]} ; Fabiana Sterren, Andrea ^[1] ; Prestianni, Cyrille ^[3] ; Adriana Cisterna, Gabriela ^{[1, 2]} ; Basei, Miguel ^[4]

Afiliação do(s) autor(es)

^[1] Univ Nacl Cordoba, CONICET, CICTERRA, Av Haya de la Torre S-N, X5015GCA, Cordoba - Argentina

^[2] Univ Nacl La Rioja, Av Luis M de la Fuente S-N, F5300, La Rioja - Argentina

^[3] Royal Belgian Inst Nat Sci, Palaeontol Dept, Rue Vautier 29, B-1000 Brussels - Belgium

^[4] Univ Sao Paulo, Inst Geociencias, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF THE GEOLOGICAL SOCIETY; v. 177, n. 6, p. 1107-1128, NOV 2020.
• Citações Web of Science: 0

Resumo

The Late Paleozoic Ice Age (LPIA) has been well recorded in the uppermost Mississippian-Pennsylvanian of Gondwana. Nevertheless, little is known about the temporal and geographic dynamics, particularly during the early Mississippian. We report on exceptional Tournaisian glaciomarine stratigraphic sections from central Argentina (Rio Blanco Basin). Encompassing c. 1400 m, these successions contain conspicuous glacigenic strata with age constraints provided by palaeontological data and U/Pb detrital zircon age spectra. A variety of marine, glaciomarine and fan-deltaic environments indicate relative sea-level variations mainly associated with tectonism and repetitive cycles of glacial activity. Provenance analysis indicates a source from the Sierras Pampeanas basement located to the east. Fifteen sequences were grouped into three depositional models: (1) Transgressive Systems Tracts (TST) to Highstand Systems Tracts (HST) sequences unaffected by glacial ice; (2) Lowstand Systems Tracts (LST) to TST and then to HST with glacial inFLuence; and (3) non-glacial Falling-Stage Systems Tracts (FSST) to TST and HST. The glacial evidence indicates that the oldest Mississippian glacial stage of the LPIA in southwestern Gondwana is constrained to the middle Tournaisian. In contrast with previous descriptions of Gondwanan coeval glacial records, our sequence analysis confirms complex hierarchical climate variability, rather than a single episode of ice advance and retreat.Supplementary material: Detailed stratigraphic sections, palaeocurrents and compositional analysis and U/Pb detrital Zr methodology and data are available at: https://doi.org/10.6084/m9.figshare.c.5011424 (AU)

• Processo FAPESP: 18/06837-3 - Idades U-Pb e isótopos de HF em zircão magmático de granitos devoniano-carboníferos como monitores do crescimento crustal e contexto geodinâmico da margem pré-andina do Gondwana Ocidental
• Beneficiário: Miguel Angelo Stipp Basei
• Linha de fomento: Auxílio à Pesquisa - Pesquisador Visitante - Internacional