Nicholas A. Regier, Brian K. Horton, Daniel Starck, Facundo Fuentes, Erin E. Donaghy, Michael P. Eddy, Tomas N. Capaldi
{"title":"Sediment provenance and depositional systems during Paleozoic tectonic and climatic transitions in the eastern Precordillera of Argentina","authors":"Nicholas A. Regier, Brian K. Horton, Daniel Starck, Facundo Fuentes, Erin E. Donaghy, Michael P. Eddy, Tomas N. Capaldi","doi":"10.1016/j.gr.2024.11.013","DOIUrl":null,"url":null,"abstract":"The Precordillera of western Argentina displays a complex pre-Andean stratigraphic record related to Paleozoic convergence along the SW margin of Gondwana. Sedimentologic and U-Pb detrital zircon geochronological results for the Silurian Rinconada Formation and Carboniferous Jejenes Formation of the eastern Precordillera provide insight into sediment provenance, drainage reorganization, and climatic/tectonic interactions during Paleozoic deformation and glaciation. Measured sections and lithofacies analyses indicate sediment gravity flow and mass-transport deposition in a Silurian submarine fan during shortening in the adjacent Famatinian orogenic belt. This foreland basin was deformed during the Late Devonian Chanic orogeny, prior to glacial incision of remnant topography during the Late Paleozoic Ice Age. Analyses of unconformities, cross-cutting relationships, and lithofacies within a Carboniferous paleovalley (Quebrada Grande, Sierra Chica de Zonda) indicate four facies associations (fjord-head delta, distal fjord, fan delta, and subglacial fan) within a fjord setting governed by glacial advance and retreat. U-Pb results for Carboniferous sandstones (7 samples, 840 analyses) indicate derivation from Western Pampean basement with progressive drainage expansion to include the Famatinian magmatic arc and Eastern Sierras Pampeanas. Evolution from a Silurian marine foreland basin to an isolated Carboniferous fjord reflects major orogenic and climatic transitions in SW Gondwana. Ordovician-Silurian (Famatinian) and Late Devonian (Chanic) shortening generated topography that was subsequently beveled by glacial erosion during the Carboniferous. We suggest that Paleozoic deformation related to subduction and terrane collision helped drive changes in sediment dispersal and basin configuration, while climate changes during regional glaciation regulated erosion/deposition and the spatial extent of sediment accommodation.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"54 1","pages":""},"PeriodicalIF":7.2000,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Gondwana Research","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1016/j.gr.2024.11.013","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The Precordillera of western Argentina displays a complex pre-Andean stratigraphic record related to Paleozoic convergence along the SW margin of Gondwana. Sedimentologic and U-Pb detrital zircon geochronological results for the Silurian Rinconada Formation and Carboniferous Jejenes Formation of the eastern Precordillera provide insight into sediment provenance, drainage reorganization, and climatic/tectonic interactions during Paleozoic deformation and glaciation. Measured sections and lithofacies analyses indicate sediment gravity flow and mass-transport deposition in a Silurian submarine fan during shortening in the adjacent Famatinian orogenic belt. This foreland basin was deformed during the Late Devonian Chanic orogeny, prior to glacial incision of remnant topography during the Late Paleozoic Ice Age. Analyses of unconformities, cross-cutting relationships, and lithofacies within a Carboniferous paleovalley (Quebrada Grande, Sierra Chica de Zonda) indicate four facies associations (fjord-head delta, distal fjord, fan delta, and subglacial fan) within a fjord setting governed by glacial advance and retreat. U-Pb results for Carboniferous sandstones (7 samples, 840 analyses) indicate derivation from Western Pampean basement with progressive drainage expansion to include the Famatinian magmatic arc and Eastern Sierras Pampeanas. Evolution from a Silurian marine foreland basin to an isolated Carboniferous fjord reflects major orogenic and climatic transitions in SW Gondwana. Ordovician-Silurian (Famatinian) and Late Devonian (Chanic) shortening generated topography that was subsequently beveled by glacial erosion during the Carboniferous. We suggest that Paleozoic deformation related to subduction and terrane collision helped drive changes in sediment dispersal and basin configuration, while climate changes during regional glaciation regulated erosion/deposition and the spatial extent of sediment accommodation.
期刊介绍:
Gondwana Research (GR) is an International Journal aimed to promote high quality research publications on all topics related to solid Earth, particularly with reference to the origin and evolution of continents, continental assemblies and their resources. GR is an "all earth science" journal with no restrictions on geological time, terrane or theme and covers a wide spectrum of topics in geosciences such as geology, geomorphology, palaeontology, structure, petrology, geochemistry, stable isotopes, geochronology, economic geology, exploration geology, engineering geology, geophysics, and environmental geology among other themes, and provides an appropriate forum to integrate studies from different disciplines and different terrains. In addition to regular articles and thematic issues, the journal invites high profile state-of-the-art reviews on thrust area topics for its column, ''GR FOCUS''. Focus articles include short biographies and photographs of the authors. Short articles (within ten printed pages) for rapid publication reporting important discoveries or innovative models of global interest will be considered under the category ''GR LETTERS''.