Oxygen Isotope Geothermometry of the Burial Metamorphic Rocks of the Precambrian Belt Supergroup, Glacier National Park, Montana

Research Article| August 01, 1973 Oxygen Isotope Geothermometry of the Burial Metamorphic Rocks of the Precambrian Belt Supergroup, Glacier National Park, Montana ERIC V. ESLINGER; ERIC V. ESLINGER 1Department of Geology, Case Western Reserve University, Cleveland, Ohio 441062Present address: Department of Geology, West Georgia College, Carrollton, Georgia 30117 Search for other works by this author on: GSW Google Scholar SAMUEL M. SAVIN SAMUEL M. SAVIN 1Department of Geology, Case Western Reserve University, Cleveland, Ohio 44106 Search for other works by this author on: GSW Google Scholar Author and Article Information ERIC V. ESLINGER 1Department of Geology, Case Western Reserve University, Cleveland, Ohio 441062Present address: Department of Geology, West Georgia College, Carrollton, Georgia 30117 SAMUEL M. SAVIN 1Department of Geology, Case Western Reserve University, Cleveland, Ohio 44106 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1973) 84 (8): 2549–2560. https://doi.org/10.1130/0016-7606(1973)84<2549:OIGOTB>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation ERIC V. ESLINGER, SAMUEL M. SAVIN; Oxygen Isotope Geothermometry of the Burial Metamorphic Rocks of the Precambrian Belt Supergroup, Glacier National Park, Montana. GSA Bulletin 1973;; 84 (8): 2549–2560. doi: https://doi.org/10.1130/0016-7606(1973)84<2549:OIGOTB>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 Isotopic evidence supports the conclusions of other studies that the Precambrian Belt rocks have been subjected to high-grade diagenesis and low-grade metamorphism. Isotopic temperatures calculated from O18/O16 ratios of coexisting quartz and illite range from 225°C to 310°C and are interpreted as being temperatures reached during metamorphism. Isotopic temperatures generally increase with maximum depth of burial. A plot of isotopic temperatures as a function of depth of burial can be extrapolated to 20°C (surface temperature) at approximately 5,500 m above our uppermost sample. This is consistent with the probable amount of overburden above this sample as inferred from stratigraphic evidence. The isotopic temperatures are also consistent with a model of equilibration during burial in a normal geothermal gradient. Feldspar underwent isotopic exchange during metamorphism but does not always appear to have attained isotopic equilibrium with quartz and illite. The isotopic data indicate some degree of disequilibrium between carbonate and quartz and suggest that the carbonate may have been more readily subject to retrograde exchange than was the silicate. The isotopic compositions of whole-rock samples vary with depth in the stratigraphic section, apparently reflecting post-depositional isotopic exchange. 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.