Plate reconstructions, aseismic ridges, and low-angle subduction beneath the Andes

Research Article| July 01, 1981 Plate reconstructions, aseismic ridges, and low-angle subduction beneath the Andes REX H. PILGER, JR. REX H. PILGER, JR. 1Department of Geology, Louisiana State University, Baton Rouge, Louisiana 70803 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1981) 92 (7): 448–456. https://doi.org/10.1130/0016-7606(1981)92<448:PRARAL>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 REX H. PILGER; Plate reconstructions, aseismic ridges, and low-angle subduction beneath the Andes. GSA Bulletin 1981;; 92 (7): 448–456. doi: https://doi.org/10.1130/0016-7606(1981)92<448:PRARAL>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 Low-angle—subduction segments beneath Peru and Chile are believed to represent interaction of the subduction zone with the aseismic Nazca and Juan Fernandez Ridges. On the basis of symmetric sea-floor–spreading models and plate-hotspot reconstructions, predicted continuations of the relatively buoyant ridges correspond well with the limits of the low-angle–subduction segments. Further, the history of interaction of the aseismic ridges with the subduction zone, as predicted by plate reconstructions, is not inconsistent with available information on volcanic episodes of the Andes, if the contemporary correlation of volcanic gaps and low-angle subduction is also applicable to the rest of the late Cenozoic.The occurrence of deep seismicity beneath the eastern flanks of the Andes is also believed to reflect the effects of low-angle subduction. The deep-seismic segments are adjacent to segments which are presently, or were recently, experiencing low-angle subduction. Thus, the deep seismicity is interpreted as representative of remnants of "normal" oceanic lithosphere subducted before interaction of aseismic ridges with the subduction zone.Other geologic phenomena are associated with low-angle subduction beneath South America, including landward shift in loci of tectonism, surficial subsidence, and Laramide-style deformation. The aseismic-ridge—buoyancy hypothesis appears to be a valuable predictive tool for the interpretation of such geologic effects. 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.