Syntectonic Recrystallization of Olivine and Modes of Flow in the Upper Mantle

Abstract

Research Article| August 01, 1970 Syntectonic Recrystallization of Olivine and Modes of Flow in the Upper Mantle HANS G AVE'LALLEMANT; HANS G AVE'LALLEMANT Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520 PRESENT ADDRESS: DEPARTMENT OF GEOLOGY, RICE UNIVERSITY, HOUSTON, TEXAS (Ave'Lallemant) Search for other works by this author on: GSW Google Scholar NEVILLE L CARTER NEVILLE L CARTER Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1970) 81 (8): 2203–2220. https://doi.org/10.1130/0016-7606(1970)81[2203:SROOAM]2.0.CO;2 Article history received: 06 Apr 1970 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation HANS G AVE'LALLEMANT, NEVILLE L CARTER; Syntectonic Recrystallization of Olivine and Modes of Flow in the Upper Mantle. GSA Bulletin 1970;; 81 (8): 2203–2220. doi: https://doi.org/10.1130/0016-7606(1970)81[2203:SROOAM]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 Olivine in dunite, peridotite, and olivine powder has been recrystallized syntectonically during compression tests at temperatures from 950°C to 1350°C, confining pressures from 5 to 30 kb, and strain rates from 10−3 to 10−8/sec. For intragranular recrystallization of the dunite, the orientations of the new grains are controlled by the host orientation. For inter-granular recrystallization and total recrystallization of the dunite and of olivine powder, the orientations of the grains are controlled dominantly by the stress. The fabric produced over the entire range of physical conditions is a [010] maximum parallel to σ1 and [001] and [100] girdles in the σ2 = σ3 plane.With few exceptions, and allowances for the experimental requirement that σ2 = σ3, fabrics in olivine tectonites are similar to those produced experimentally. Such probable upper mantle source materials as ultramafic nodules in diamond-bearing kimberlites and in under-saturated basalts and "Alpine-type" peridotites show these same preferred orientations. We propose, therefore, that Syntectonic recrystallization is an important or dominant mode of flow in the upper mantle at temperatures above about 500°C. The implications of this conclusion, as they bear on seismicity and seismic anisotropy, are considered in light of the two most seriously regarded hypotheses advanced to explain motions of spreading plates of the lithosphere. 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.