Research Article| January 01, 1986 Pliocene near-trench magmatism in southern Chile: A possible manifestation of ridge collision Randall D. Forsythe; Randall D. Forsythe 1Department of Geological Sciences, Rutgers University, New Brunswick, New Jersey 08903 Search for other works by this author on: GSW Google Scholar Eric P. Nelson; Eric P. Nelson 2Geology Department, Colorado School of Mines, Golden, Colorado 80401 Search for other works by this author on: GSW Google Scholar Michael J. Carr; Michael J. Carr 3Department of Geological Sciences, Rutgers University, New Brunswick, New Jersey 08903 Search for other works by this author on: GSW Google Scholar Margaret E. Kaeding; Margaret E. Kaeding 3Department of Geological Sciences, Rutgers University, New Brunswick, New Jersey 08903 Search for other works by this author on: GSW Google Scholar Miguel Herve; Miguel Herve 4Servicio Nacional de Geología y Minería, Casilla 10654, Santiago, Chile Search for other works by this author on: GSW Google Scholar Constantino Mpodozis; Constantino Mpodozis 4Servicio Nacional de Geología y Minería, Casilla 10654, Santiago, Chile Search for other works by this author on: GSW Google Scholar Jose Manuel Soffia; Jose Manuel Soffia 5Departamento de Geología y Geofísica, Universidad de Chile, Santiago, Chile Search for other works by this author on: GSW Google Scholar Salvador Harambour Salvador Harambour 5Departamento de Geología y Geofísica, Universidad de Chile, Santiago, Chile Search for other works by this author on: GSW Google Scholar Geology (1986) 14 (1): 23–27. https://doi.org/10.1130/0091-7613(1986)14<23:PNMISC>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 MailTo Tools Icon Tools Get Permissions Search Site Citation Randall D. Forsythe, Eric P. Nelson, Michael J. Carr, Margaret E. Kaeding, Miguel Herve, Constantino Mpodozis, Jose Manuel Soffia, Salvador Harambour; Pliocene near-trench magmatism in southern Chile: A possible manifestation of ridge collision. Geology 1986;; 14 (1): 23–27. doi: https://doi.org/10.1130/0091-7613(1986)14<23:PNMISC>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 SocietyGeology Search Advanced Search Abstract Eight shallow-level intrusions and an ophiolite complex have recently been discovered in a remote region along the Pacific coast of southern Chile known as the Taitao Peninsula. The magmatic rocks are found only 10 to 15 km from the buried extension of the Peru-Chile Trench. The ophiolite body includes serpentinized ultramaflc rocks, gabbro, dikes, and an interbedded sequence of volcanic and marine sedimentary rocks. More regionally distributed granodiorite plutons and porphyritic stocks and sills intrude pre-Late Jurassic basement as well as Tertiary marine sequences of the South American forearc. K-Ar ages of 3.5 to 4.0 Ma of the ophiolite and other intrusions suggest that these rocks represent a short-lived pulse of Pliocene magmatism. Directly seaward of the Taitao Peninsula a segment of the Chile Rise bounded by the Tres Monies and Taitao fracture zones collided with the Chilean forearc and was subducted about 2.5 to 4.0 Ma. Because of this good spatial and temporal correlation, the magmatic activity of the Taitao Peninsula is likely to be a direct result of ridge subduction. 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.