New isotopic temperature estimates for early silica diagenesis in bedded cherts

Research Article| June 01, 1993 New isotopic temperature estimates for early silica diagenesis in bedded cherts Ronald K. Matheney; Ronald K. Matheney 1Department of Geology and Geological Engineering, University of North Dakota, Grand Forks, North Dakota 58202-8358 Search for other works by this author on: GSW Google Scholar L. Paul Knauth L. Paul Knauth 2Department of Geology, Arizona State Unversity, Tempe, Arizona 85287-1404 Search for other works by this author on: GSW Google Scholar Geology (1993) 21 (6): 519–522. https://doi.org/10.1130/0091-7613(1993)0212.3.CO;2 Article history first online: 02 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 Ronald K. Matheney, L. Paul Knauth; New isotopic temperature estimates for early silica diagenesis in bedded cherts. Geology 1993;; 21 (6): 519–522. doi: https://doi.org/10.1130/0091-7613(1993)0212.3.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 When analyzed by a stepwise fluorination technique that reduces undesired oxygen contributions from hydroxyl and water, opal-CT samples from the siliceous member of the Miocene Monterey Formation, California, yield δ18O values that contribute to mounting evidence that silica diagenesis in bedded chert can occur at much lower temperatures than previously supposed. Monterey opal-CT δ18O values of 37.5‰ and 36.3‰ point to diagenetic temperatures at least as low as 17-21 °C, rather than the 35-50 °C values normally inferred. Our results suggest that hydration waters can significantly reduce the bulk δ18O of opal-CT and that special analytical techniques and consideration of water/rock ratios are warranted for isotope thermometry off diagenetic silica transformations. 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.