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High Temperature Flow of Dunite and Peridotite

1970; Geological Society of America; Volume: 81; Issue: 8 Linguagem: Inglês

10.1130/0016-7606(1970)81[2181

1943-2674

Neville L. Carter, Hans G. AvéLallemant,

Geological and Geochemical Analysis

Research Article| August 01, 1970 High Temperature Flow of Dunite and Peridotite 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 HANS G AVE'LALLEMANT HANS G AVE'LALLEMANT Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520 PRESENT ADDRESS (AVE'LALLEMANT): DEPARTMENT OF GEOLOGY, RICE UNIVERSITY, HOUSTON, TEXAS 77001 Search for other works by this author on: GSW Google Scholar Author and Article Information NEVILLE L CARTER Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520 HANS G AVE'LALLEMANT PRESENT ADDRESS (AVE'LALLEMANT): DEPARTMENT OF GEOLOGY, RICE UNIVERSITY, HOUSTON, TEXAS 77001 Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520 Publisher: Geological Society of America Received: 06 Apr 1970 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1970, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1970) 81 (8): 2181–2202. https://doi.org/10.1130/0016-7606(1970)81[2181:HTFODA]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 Email Permissions Search Site Citation NEVILLE L CARTER, HANS G AVE'LALLEMANT; High Temperature Flow of Dunite and Peridotite. GSA Bulletin 1970;; 81 (8): 2181–2202. doi: https://doi.org/10.1130/0016-7606(1970)81[2181:HTFODA]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 Deformation experiments on dunite and peridotite, both in the presence and absence of externally released H2O, have been carried out in solid pressure media apparatus in the confining pressure range 5 to 30 kb, temperature interval 300°C to 1400°C at constant strain rates ranging from 10−3 to 10−8/sec. At the lower temperatures and higher rates, olivine deforms by plastic flow on the system T = (110), t = [001], the slip systems changing with increasing temperature and decreasing strain rate through {0kl} [100] to (010) [100]. At a strain rate of 10−3/sec, polygonization (dislocation climb) is first observed at about 1000°C and recrystallization first appears at about 1050°C; these temperatures decrease by about 50°C with a ten-fold reduction in strain rate.Preliminary mechanical results indicate that steady state deformation takes place only in the temperature-strain rate range in which the diffusion controlled processes of polygonization and recrystallization are important or dominant. The steady state data are best fit by a power creep equation with the stress exponent, n ≃ 2.4 and 4.8 and the creep activation energy, Q ≃ 80 and 120 Kcal/mole for deformation in the presence and absence of externally released H2O, respectively. Extrapolation of the equation for the dunite deformed dry to a representative geological strain rate of 10−14/sec gives shear stresses in the range 100 bars to 1 bar and effective viscosities from 1023 to 1020 poise for the temperature interval 1000°C to 2000°C. The estimated variation in shear stress over most of the upper mantle, where T/Tm (the ratio of ambient to melting temperature) is greater than 0.75, is about 6 to 15 bars, and in viscosity in the range 1020 to 1021 poise. These inferences are in accord with estimates based on other geophysical observations, and our results suggest that flow in the upper mantle may be governed primarily by a non-linear creep law. 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.