Jurassic and Early Cretaceous island arc volcanism, extension, and subsidence in the Coast Range of central Chile

Research Article| December 01, 1995 Jurassic and Early Cretaceous island arc volcanism, extension, and subsidence in the Coast Range of central Chile Mario Vergara; Mario Vergara 1Departamento de Geología, Universidad de Chile, Casilla 13518 Santiago, Chile Search for other works by this author on: GSW Google Scholar Beatriz Levi; Beatriz Levi 2Department of Geology and Geochemistry, Stockholm University, S-10691 Stockholm, Sweden Search for other works by this author on: GSW Google Scholar Jan Olov Nyström; Jan Olov Nyström 3Swedish Museum of Natural History, S-10405 Stockholm, Sweden Search for other works by this author on: GSW Google Scholar Alejandro Cancino Alejandro Cancino 1Departamento de Geología, Universidad de Chile, Casilla 13518 Santiago, Chile Search for other works by this author on: GSW Google Scholar Author and Article Information Mario Vergara 1Departamento de Geología, Universidad de Chile, Casilla 13518 Santiago, Chile Beatriz Levi 2Department of Geology and Geochemistry, Stockholm University, S-10691 Stockholm, Sweden Jan Olov Nyström 3Swedish Museum of Natural History, S-10405 Stockholm, Sweden Alejandro Cancino 1Departamento de Geología, Universidad de Chile, Casilla 13518 Santiago, Chile Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1995) 107 (12): 1427–1440. https://doi.org/10.1130/0016-7606(1995)107<1427:JAECIA>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 Email Permissions Search Site Citation Mario Vergara, Beatriz Levi, Jan Olov Nyström, Alejandro Cancino; Jurassic and Early Cretaceous island arc volcanism, extension, and subsidence in the Coast Range of central Chile. GSA Bulletin 1995;; 107 (12): 1427–1440. doi: https://doi.org/10.1130/0016-7606(1995)107<1427:JAECIA>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 More than 2000 km3 of acid and 9000 km3 of basic volcanic rocks formed during the Jurassic and Early Cretaceous in the Coast Range of central Chile, between 32°30′S and 34°S. These rocks, which constitute the major part of an •15-km-thick pile of alternately marine and continental deposits, issued from volcanic arcs situated between a land area with Paleozoic basement in the west and a marginal sea in the east. Asthenospheric upwelling led to extension and bimodal volcanism; the volcanic products were deposited in intra-arc basins subsiding at high rates (100–300 m/m.y.). The source of the magmas became more depleted with time due to an increase in degree of partial melting, and their compositions were modified by subduction-related fluids and contamination with a progressively thinner and younger crust. The basic lavas are of high-K calc-alkaline to shoshonitic affinity, chemically resembling the lavas found in some mature island arcs in the western Pacific. The extension and subsidence resulted in a low-relief topography close to sea level, in contrast with the present-day convergent type of Andean volcanism at the same latitude where calc-alkaline intermediate lavas erupt from volcanoes at great height above a thick crust. 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.