Steady-State Flow in Marble at 500° to 800°C

Abstract

Research Article| April 01, 1972 Steady-State Flow in Marble at 500° to 800°C H. C HEARD; H. C HEARD Lawrence Livermore Laboratory, University of California, Livermore, California 94550 Search for other works by this author on: GSW Google Scholar C. B RALEIGH C. B RALEIGH U.S Geological Survey, NCER, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Author and Article Information H. C HEARD Lawrence Livermore Laboratory, University of California, Livermore, California 94550 C. B RALEIGH U.S Geological Survey, NCER, Menlo Park, California 94025 Publisher: Geological Society of America Received: 02 Sep 1971 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1972, 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 (1972) 83 (4): 935–956. https://doi.org/10.1130/0016-7606(1972)83[935:SFIMAT]2.0.CO;2 Article history Received: 02 Sep 1971 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 H. C HEARD, C. B RALEIGH; Steady-State Flow in Marble at 500° to 800°C. GSA Bulletin 1972;; 83 (4): 935–956. doi: https://doi.org/10.1130/0016-7606(1972)83[935:SFIMAT]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 The stress-strain behavior of Yule marble, both parallel and normal to the foliation, has been determined in a series of constant strain-rate extension tests at 5000 bars confining pressure, at temperatures of 500° to 800° C and at strain rates ranging from 10−3 to 10−7/sec. These data correlate well with earlier results at 25° to 500° C and l0−1 to 10−8/sec. Steady-state flow is dominant at 400° C and rates <10−7/sec, at 500° C < 10−4/sec, and at all strain rates at higher temperatures. Transient flow (work hardening) is prevalent at lower temperatures and higher rates.Transmission and reflection microscopy as well as etch-pit studies reveal that translation gliding on r, f and twinning on e are dominant in the transient region, becoming less prominent in the steady-state region at high temperatures. Polygonization by dislocation climb becomes characteristic in the steady-state flow region, along with intergranular and intra-granular recrystallization. Grain boundary sliding is present, but of minor importance.The effect of temperature and strain rate on the mechanical behavior, as well as on the correlation of subgrain formation and recrystallization with steady-state flow, is consistent with a diffusion-controlled process. Comparison of the data with several models for diffusion-controlled flow show poor correlation with the Eyring equation, ε = A exp ( −E/RT) sinh (Bσ), but excellent correlation with the Weertman equation, ε = C exp ( −E/RT) <σN.The activation energy E and the stress exponent N are nearly identical for both orientations of this highly anisotropic marble, and thus this material becomes nearly isotropic (mechanically) for steady-state flow. On the basis of the empirical-flow equation, extrapolations to representative natural strain rates of 3 × 10−14/sec predict stresses of 103 bars at 250° C, ranging to about 30 bars at 700° C. Work-hardening can be expected at these rates at temperatures <250° C; in this region, this marble is expected to be mechanically anisotropic. Calculated equivalent viscosities at natural strain rates range from 3 × 1022 poises at 25° to 4 × 1020 poises at 700° C. 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.