Study of the Structural State and Composition of Feldspars of the Bedford Augen Gneiss, New York

Abstract

Research Article| November 01, 1971 Study of the Structural State and Composition of Feldspars of the Bedford Augen Gneiss, New York DENNIS L HIPPLE DENNIS L HIPPLE Miami-Dade Junior College, Miami, Florida 33167 Search for other works by this author on: GSW Google Scholar Author and Article Information DENNIS L HIPPLE Miami-Dade Junior College, Miami, Florida 33167 Publisher: Geological Society of America Received: 11 Jan 1971 Revision Received: 10 May 1971 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1971, 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 (1971) 82 (11): 3213–3220. https://doi.org/10.1130/0016-7606(1971)82[3213:SOTSSA]2.0.CO;2 Article history Received: 11 Jan 1971 Revision Received: 10 May 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 DENNIS L HIPPLE; Study of the Structural State and Composition of Feldspars of the Bedford Augen Gneiss, New York. GSA Bulletin 1971;; 82 (11): 3213–3220. doi: https://doi.org/10.1130/0016-7606(1971)82[3213:SOTSSA]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 A petrographic and x-ray study of the Bedford augen gneiss suggests the temperature during metamorphism ranged from 400°C in the southern part of the body to approximately 700°C in the northern part. The mineral assemblage of sillimanite-almandine-orthoclase, a subfacies of the amphibolite facies (Winkler, 1967, p. 106) that characterizes the northern part of the augen gneiss mass, suggests the temperature of formation was 550° to 700°C. Microcline and abundant muscovite in stable association with the kyanite-almandine-muscovite subfacies of the amphibolite facies characteristic of the southeast half of the mass suggests the temperature here was 400° to 500°C (Steiger and Hart, 1967). X-ray diffraction analysis indicates that two crystallographic forms of potassium feldspar, orthoclase, and maximum microcline, exist in several structural states, further suggesting a temperature gradient increasing from south to north in the body. 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.