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The Loma Seca Tuff and the Calabozos caldera: A major ash-flow and caldera complex in the southern Andes of central Chile

1984; Geological Society of America; Volume: 95; Issue: 1 Linguagem: Inglês

10.1130/0016-7606(1984)95 2.0.co;2

1943-2674

Wes Hildreth, Anita L. Grunder, Robert E. Drake,

Evolution and Paleontology Studies

Research Article| January 01, 1984 The Loma Seca Tuff and the Calabozos caldera: A major ash-flow and caldera complex in the southern Andes of central Chile WES HILDRETH; WES HILDRETH 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar ANITA L. GRUNDER; ANITA L. GRUNDER 2Department of Geology, Stanford University, Stanford, California 94305 Search for other works by this author on: GSW Google Scholar ROBERT E. DRAKE ROBERT E. DRAKE 3Department of Geology and Geophysics, University of California, Berkeley, California 94720 Search for other works by this author on: GSW Google Scholar Author and Article Information WES HILDRETH 1U.S. Geological Survey, Menlo Park, California 94025 ANITA L. GRUNDER 2Department of Geology, Stanford University, Stanford, California 94305 ROBERT E. DRAKE 3Department of Geology and Geophysics, University of California, Berkeley, California 94720 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1984) 95 (1): 45–54. https://doi.org/10.1130/0016-7606(1984)95 2.0.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 WES HILDRETH, ANITA L. GRUNDER, ROBERT E. DRAKE; The Loma Seca Tuff and the Calabozos caldera: A major ash-flow and caldera complex in the southern Andes of central Chile. GSA Bulletin 1984;; 95 (1): 45–54. doi: https://doi.org/10.1130/0016-7606(1984)95 2.0.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 A 26 × 14-km composite ring-structure caldera of late Pleistocene age has been discovered and mapped near the Andean crest in central Chile (35°30′S). Rhyodacitic to dacitic zoned ash-flow sheets, each representing 150 to 300 km3 of magma, were emplaced 0.8, 0.3, and 0.15 m.y. ago; the youngest of the associated collapses was closely followed by resurgent doming of the caldera floor and development of a longitudinal graben. Postcaldera eruptions of dacite and andesite have persisted into Holocene time, and active hot springs are abundant along caldera-marginal and resurgent fault systems, suggesting a significant geothermal-energy resource. The Pleistocene eruption rate of this district and the abundance of older Quaternary to Miocene ash-flow remnants in the 33°S to 36°S segment of the glaciated southern Andes indicate that ash-flow magmatism has been no less important here than in the arid central Andes (16°S–28°S), where ash-flow sheets are far better preserved. 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.