Provenance analysis of Devonian peripheral foreland basins in SW Gondwana, case of the Gualilán Group, Precordillera Argentina

URIZ, NORBERTO JAVIER; ABRE, PAULINA; CINGOLANI, CARLOS ALBERTO; CINGOLANI, CARLOS ALBERTO; ARNOL, JONATAN ARIEL; BASEI, MIGUEL ANGELO STIPP; ARNOL, JONATAN ARIEL; BASEI, MIGUEL ANGELO STIPP; URIZ, NORBERTO JAVIER; ABRE, PAULINA

INTERNATIONAL JOURNAL OF EARTH SCIENCES

SPRINGER

Año: 2020 vol. 109 p. 2467 - 2494

1437-3254

We carried out a sedimentary provenance analysis of the Devonian GualilánGroup, Central Precordillera of western Argentina, focusing on thesiliciclastic record of the Talacasto (Lower Devonian) and the Punta Negra(Lower-Middle Devonian) formations. Provenance is determined based onpetrography, heavy minerals, whole-rock geochemistry, Sm?Nd isotopes,and U?Pb detrital zircon dating. Sandstones are composed of quartz,feldspar, and metamorphic and plutonic lithoclasts. The Gualilán Groupunderwent moderate weathering indicated by CIA values and Th/U ratiosbelow 76 and 4.9, respectively. Th/Sc, Zr/Sc, Cr/V and La/Th ratios,negative Eu-anomalies and REE patterns point to felsic sourcecompositions. The heavy minerals and zircon morphologies indicate thathigh-grade metamorphic and igneous rocks provided the bulk of detritus.TDM ages between 1.40 and 1.46 Ga and ε (t) values ranging from− 9.21 to − 11.13 constrain the signature of the sources. U?Pb detritalzircon ages for the Talacasto Formation are equally distributed between theFamatinian (Late Cambrian?Late Devonian), Pampean?Brazilian(Neoproterozoic?Early Cambrian) and Grenvillian-Sunsas(Mesoproterozoic) orogenic cycles. Detrital zircon ages of the Punta NegraFormation were dominantly supplied from Mesoproterozoic rocks, linked tothe Grenvillian-Sunsas orogeny. The data indicate a provenance from rockslocated eastwards of the basin represented by the basement of the PampeanRanges. The peripheral foreland basin developed during the post-collisionalregime that followed the accretion of Cuyania against Gondwana. Whereaseastern and western Pampean Ranges provided detritus to the TalacastoFormation, the Punta Negra Formation was sourced by the westernPampean Ranges, implying exhumation and erosion of such basementduring the Devonian.