Research Article| May 01, 1976 Obsidian hydration dating and correlation of Bull Lake and Pinedale Glaciations near West Yellowstone, Montana KENNETH L. PIERCE; KENNETH L. PIERCE 1U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar JOHN D. OBRADOVICH; JOHN D. OBRADOVICH 1U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar IRVING FRIEDMAN IRVING FRIEDMAN 1U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Author and Article Information KENNETH L. PIERCE 1U.S. Geological Survey, Denver, Colorado 80225 JOHN D. OBRADOVICH 1U.S. Geological Survey, Denver, Colorado 80225 IRVING FRIEDMAN 1U.S. Geological Survey, Denver, Colorado 80225 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1976) 87 (5): 703–710. https://doi.org/10.1130/0016-7606(1976)87<703:OHDACO>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 Email Permissions Search Site Citation KENNETH L. PIERCE, JOHN D. OBRADOVICH, IRVING FRIEDMAN; Obsidian hydration dating and correlation of Bull Lake and Pinedale Glaciations near West Yellowstone, Montana. GSA Bulletin 1976;; 87 (5): 703–710. doi: https://doi.org/10.1130/0016-7606(1976)87<703:OHDACO>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 ages of the last two glaciations near West Yellowstone, Montana, can be calculated by obsidian hydration techniques that are calibrated by K-Ar dating of obsidian-bearing lava flows. The average age of glacial abrasion of obsidian in the Pinedale terminal moraines is about 30,000 yr, with most age measurements between 20,000 and 35,000 yr. For the Bull Lake moraines, it is about 140,000 yr, with most measurements between 130,000 and 155,000 yr. This age for the Bull Lake moraines is also supported by geologic relations that show that the moraines are older than a rhyolite flow dated by K-Ar as 114,500 ± 7,300 yr old (lσ).These obsidian hydration ages of the Pinedale and Bull Lake Glaciations correlate well with the last two cold intervals of the marine record. The age determined for the Bull Lake Glaciation near West Yellowstone antedates the last interglaciation of the marine record, which is commonly correlated with the Sangamon Interglaciation.Our results suggest correlation of the Pinedale Glaciation near West Yellowstone with much or all of the Wisconsin Glaciation and of the Bull Lake with the late Illinoian. This differs with the commonly accepted correlation of the Pinedale with the late ("classical") Wisconsin and of the Bull Lake with the early Wisconsin. The correlation of Bull Lake with late Illinoian appears equally or more compatible with traditional criteria for correlation, namely comparative soil development and degree of preservation of morainal morphology. 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.
No takes yet. Share an insight, caveat, or question.
Pierce et al. (1976) studied this question.