Stable isotope study of fluid inclusions in fluorite from Idaho: Implications for continental climates during the Eocene

Abstract

Research Article| March 01, 1993 Stable isotope study of fluid inclusions in fluorite from Idaho: Implications for continental climates during the Eocene Robert R. Seal, II; Robert R. Seal, II 1U.S. Geological Survey, 954 National Center, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar Robert O. Rye Robert O. Rye 2U.S. Geological Survey, 963 Denver Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Author and Article Information Robert R. Seal, II 1U.S. Geological Survey, 954 National Center, Reston, Virginia 22092 Robert O. Rye 2U.S. Geological Survey, 963 Denver Federal Center, Denver, Colorado 80225 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1993) 21 (3): 219–222. https://doi.org/10.1130/0091-7613(1993)021<0219:SISOFI>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 MailTo Tools Icon Tools Get Permissions Search Site Citation Robert R. Seal, Robert O. Rye; Stable isotope study of fluid inclusions in fluorite from Idaho: Implications for continental climates during the Eocene. Geology 1993;; 21 (3): 219–222. doi: https://doi.org/10.1130/0091-7613(1993)021<0219:SISOFI>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 Isotopic studies of fluid inclusions from meteoric water-dominated epithermal ore deposits offer a unique opportunity to study paleoclimates because the fluids can provide direct samples of ancient waters. The oxygen and hydrogen isotope compositions of meteoric waters vary because of changes in climatic variables such as mean annual temperature of precipitation, relative humidity, origin and history of air masses, and the isotope composition of the oceans. Inclusion fluids found in fluorite (CaF2) are especially useful because their host is devoid of oxygen or hydrogen, thus precluding postentrapment isotope exchange. Fluorite-hosted fluid inclusions from the Eocene (51-50 Ma) epithermal deposits of the Bayhorse mining district, northeastern Idaho, have low salinities, most less than 0.6 equivalent wt% NaCl, and low to moderate homogenization temperatures (98 to 146 °C), indicating meteoric origins for the fluids. Oxygen and hydrogen isotope data on inclusion fluids are almost identical to those of modern meteoric waters in the area. The equivalence of the isotope composition of the Eocene inclusion fluids and modern meteoric waters indicates that the Eocene climatic conditions were similar to those today. This conclusion supports the climate modeling of Sloan and Barron, who suggested that the climates of continental interiors do not reflect the magnitude of warming preserved by the deep-ocean paleoclimate record during the Eocene. 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.