Feldspar-influenced rock rheologies

Abstract

Research Article| December 01, 1988 Feldspar-influenced rock rheologies Susanne U. Janecke; Susanne U. Janecke 1Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112-1180 Search for other works by this author on: GSW Google Scholar James P. Evans James P. Evans 2Department of Geology, Utah State University, Logan, Utah 84322-0705 Search for other works by this author on: GSW Google Scholar Author and Article Information Susanne U. Janecke 1Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112-1180 James P. Evans 2Department of Geology, Utah State University, Logan, Utah 84322-0705 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1988) 16 (12): 1064–1067. https://doi.org/10.1130/0091-7613(1988)016<1064:FIRR>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Susanne U. Janecke, James P. Evans; Feldspar-influenced rock rheologies. Geology 1988;; 16 (12): 1064–1067. doi: https://doi.org/10.1130/0091-7613(1988)016<1064:FIRR>2.3.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 SocietyGeology Search Advanced Search Abstract Progressive fracture, subsequent cataclasis, and syntectonic alteration of feldspar to phyllosilicates transformed a massive granite into a quartz-mica phyllonite during early Tertiary deformation in a 20-30-m-wide shear zone in southeastern Arizona. The ductile deformation proceeded at temperatures and pressures approximating, middle to upper crustal levels. Most of the deformation was taken up by the feldspar and its alteration products. Quartz deformed by both brittle fracture and crystal plastic mechanisms. These results show that under certain temperature-pressure-strain rate conditions feldspars are weaker than quartz. The observed deformation mechanisms indicate that the brittle to ductile transition in fault zones is not simply a function of the onset of temperature-activated plastic deformation in quartz nor of the frictional behavior of rocks, as inferred in the familiar strength vs. depth curves. It is more likely that the transition is complex and depends on a variety of parameters. One such factor delineated in this study is the fracture and fracture-facilitated syntectonic alteration of feldspar under hydrated conditions. 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.