Pre-Andean orogenesis in the Coast Ranges of central Chile

Abstract

Research Article| July 01, 1985 Pre-Andean orogenesis in the Coast Ranges of central Chile TERENCE T. KATO TERENCE T. KATO 1Department of Earth and Space Sciences, University of California, Los Angeles, Los Angeles, California 90024 Search for other works by this author on: GSW Google Scholar Author and Article Information TERENCE T. KATO 1Department of Earth and Space Sciences, University of California, Los Angeles, Los Angeles, California 90024 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1985) 96 (7): 918–924. https://doi.org/10.1130/0016-7606(1985)96<918:POITCR>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 TERENCE T. KATO; Pre-Andean orogenesis in the Coast Ranges of central Chile. GSA Bulletin 1985;; 96 (7): 918–924. doi: https://doi.org/10.1130/0016-7606(1985)96<918:POITCR>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 An intense structural-metamorphic event of probable Permian-Triassic age is inferred from petrologic and field observations of low-grade schists from the Coast Ranges of central Chile between latitudes 38°S and 43°S. Relict almandine-rich garnet, biotite, and aluminous amphibole in mafic schists are replaced by a pervasive assemblage consisting of albite + chlorite + epidote + actinolite + sphene ± quartz: ± stilpnomelane ± white mica ± iron oxide. Chemographic analysis of phase compatibilities based on electron microprobe analyses suggests a regional retrogradation from earlier upper greenschist and/or epidote amphibolite to lower greenschist facies. A regional northwest-southeast-trending fabric within the terrane was imposed during the lower greenschist metamorphism which involved widespread reintroduction of fluids into the system. This major orogenic event is thought to be the culminating episode in a subduction-related accretionary process along the late Paleozoic margin of South America. Convergence may have been markedly oblique to the present north-south-trending continental margin. 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.