The fixed-hotspot hypothesis and origin of the Easter—Sala y Gomez—Nazca trace

Abstract

Research Article| July 01, 1981 The fixed-hotspot hypothesis and origin of the Easter—Sala y Gomez—Nazca trace 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 DAVID W. HANDSCHUMACHER DAVID W. HANDSCHUMACHER 2Seafloor Division, Code 360, Naval Ocean Research and Development Activity, NSTL Station, MS 39529 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1981) 92 (7): 437–446. https://doi.org/10.1130/0016-7606(1981)92<437:TFHAOO>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation REX H. PILGER, DAVID W. HANDSCHUMACHER; The fixed-hotspot hypothesis and origin of the Easter—Sala y Gomez—Nazca trace. GSA Bulletin 1981;; 92 (7): 437–446. doi: https://doi.org/10.1130/0016-7606(1981)92<437:TFHAOO>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 Reconstructions of the Pacific and Nazca plates suggest that both the Nazca and Tuamotu Ridges originated from a melting anomaly which existed beneath the Pacific-Farallon Ridge during the time interval between anomalies 19 and 11, as would be predicted from the fixed-hotspot hypothesis. The hotspot hypothesis, interpreted according to morphology of the Easter-Sala y Gomez-Nazca trace, would further suggest that the hotspot was located entirely beneath the Nazca plate during the time interval between anomalies 11 and 2′. At the end of this interval, the eastern boundary of the Easter plate formed, centered above the hotspot. According to this scheme, the present location of the hotspot is about 200 km west of Easter Island.However, the Easter model is incompatible with the hotspot model for the Hawiian-Emperior chain, if the hotspots are fixed relative to one another, as the age of the point on the Tuamotu Ridge which corresponds with the Hawaiian-Emperor bend (53 to 55 m.y.) is significantly greater than the age of the bend (43 m.y.). The fixed-hostpot hypothesis can be satisfied by the two traces only if one or a combination of the following conditions is met: the kinematic age of the Hawaiian-Emperor bend is substantially greater than the isotopically dated age, the magnetic-anomaly time scale is in significant error, and/or magnetic-anomaly identifications in the vicinity of the Tuamotu Ridge are erroneous.It might appear that other mechanisms for the origin of hotspot traces are preferable to the hotspot hypothesis. The most promising of these involves propagating fractures resulting from intraplate stress. This hypothesis has the advantage of accommodating anomalies in some hotspot traces, such as persistence of igneous activity long after passage of the trace over the hotspot. 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.