High-pressure behavior of kyanite; decomposition of kyanite into stishovite and corundum

Abstract

Other| June 01, 1997 High-pressure behavior of kyanite; decomposition of kyanite into stishovite and corundum Max W. Schmidt; Max W. Schmidt CNRS-URA, Clermont-Ferrand, France Search for other works by this author on: GSW Google Scholar Stefano Poli; Stefano Poli Bayerisches Geoinstitute, Federal Republic of Germany Search for other works by this author on: GSW Google Scholar Paola Comodi; Paola Comodi Universita degli Studi di Milano, Italy Search for other works by this author on: GSW Google Scholar Pier Francesco Zanazzi Pier Francesco Zanazzi Universita di Perugia, Italy Search for other works by this author on: GSW Google Scholar American Mineralogist (1997) 82 (5-6): 460–466. https://doi.org/10.2138/am-1997-5-603 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Max W. Schmidt, Stefano Poli, Paola Comodi, Pier Francesco Zanazzi; High-pressure behavior of kyanite; decomposition of kyanite into stishovite and corundum. American Mineralogist 1997;; 82 (5-6): 460–466. doi: https://doi.org/10.2138/am-1997-5-603 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 SocietyAmerican Mineralogist Search Advanced Search Abstract The pressure stability of kyanite was experimentally reversed with the use of a multi-anvil apparatus. Kyanite was found to decompose into its oxides stishovite and corundum between 14 ± 0.5 GPa (at 1000 °C) and 17.5 ± 1.0 GPa (at 2000 °C).Reliable thermodynamic calculations can be performed to temperatures of approximately 1500 °C. Up to this temperature, the location of the equilibrium kyanite = corundum + stishovite, determined in this study, constrains the equilibrium coesite = stishovite. A set of thermodynamic data was calculated by linear programming from the kyanite breakdown reaction and the coesite = stishovite equilibrium. Feasible values for the fitted thermo-dynamic properties are –28.5 to –26.3 MPa/K for the temperature derivative of the bulk modulus [(dK/dT)P] of kyanite, –815254 to –813635 J/mol for G(1298)0 of stishovite, and 24.6 to 26.3 J/mol · K forS(1298)0 of stishovite.The experimental results indicate (1) that in peraluminous eclogites of basaltic or sedimentary origin, stishovite may coexist stably with corundum at a depth greater than 420–450 km and (2) that in an inhomogeneous Al-enriched mantle, corundum could be a minor constituent in the lower mantle. 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.