Transition from back-arc to foreland basin development in the southernmost Andes: Stratigraphic record from the Ultima Esperanza District, Chile

Abstract

Research Article| January 01, 1991 Transition from back-arc to foreland basin development in the southernmost Andes: Stratigraphic record from the Ultima Esperanza District, Chile TERRY J. WILSON TERRY J. WILSON 1Department of Geology and Mineralogy, Ohio State University, Columbus, Ohio 43210 Search for other works by this author on: GSW Google Scholar Author and Article Information TERRY J. WILSON 1Department of Geology and Mineralogy, Ohio State University, Columbus, Ohio 43210 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1991) 103 (1): 98–111. https://doi.org/10.1130/0016-7606(1991)103<0098:TFBATF>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation TERRY J. WILSON; Transition from back-arc to foreland basin development in the southernmost Andes: Stratigraphic record from the Ultima Esperanza District, Chile. GSA Bulletin 1991;; 103 (1): 98–111. doi: https://doi.org/10.1130/0016-7606(1991)103<0098:TFBATF>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract During the Mesozoic evolution of the southernmost Andes, back-arc basin formation in an extensional setting was followed by foreland basin development in a compressional setting. A stratigraphic record of this tectonic transition is described from Jurassic and Cretaceous rock units exposed in the Patagonian fold-thrust belt at 51°S latitude. Initiation of an extensional deep-marine trough in Late Jurassic time is documented by interstratified rhyolites and marine mudstones in the Tobifera Formation. Development of the Early Cretaceous Rocas Verdes back-arc basin is recorded by Zapata Formation submarine-slope deposits, which draped the west-facing, passively subsiding cratonic margin of the basin. The onset of Andean compressional orogenesis and creation of the Magallanes foreland basin is marked by the influx of coarse-grained sandstone turbidites of the Albian-Cenomanian Punta Barrosa Formation. During Late Cretaceous time, the foreland basin configuration consisted of a narrow foredeep trough bounded by a gently sloping foreland ramp on the craton to the east. This geometry reflects greater flexural subsidence of the stretched and thermally weakened passive back-arc basin margin beneath the load of the obducted Rocas Verdes basin floor. Changes in depositional regime and sediment dispersal patterns in the latest Cretaceous, together with an eastward shift in the Magallanes basin depocenter, record cratonward migration of deformation in the Patagonian fold-thrust belt. Loading of the thicker, cratonic lithosphere caused subsidence of the foreland ramp to form a wide flexural basin. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.