Mid-Miocene (Barstovian) environmental and tectonic setting near Yellowstone Park, Wyoming and Montana

Research Article| November 01, 1989 Mid-Miocene (Barstovian) environmental and tectonic setting near Yellowstone Park, Wyoming and Montana ANTHONY D. BARNOSKY; ANTHONY D. BARNOSKY 1Section of Vertebrate Fossils, Carnegie Museum of Natural History, 4400 Forbes Ave., Pittsburgh, Pennsylvania 15213 Search for other works by this author on: GSW Google Scholar WAYNE J. LABAR WAYNE J. LABAR 2Department of Geology and Planetary Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1989) 101 (11): 1448–1456. https://doi.org/10.1130/0016-7606(1989)101<1448:MMBEAT>2.3.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 ANTHONY D. BARNOSKY, WAYNE J. LABAR; Mid-Miocene (Barstovian) environmental and tectonic setting near Yellowstone Park, Wyoming and Montana. GSA Bulletin 1989;; 101 (11): 1448–1456. doi: https://doi.org/10.1130/0016-7606(1989)101<1448:MMBEAT>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 SocietyGSA Bulletin Search Advanced Search Abstract Middle Miocene (ca. 10.5-16.0 Ma) deposits in the Greater Yellowstone region are confined to the newly defined Hepburn's Mesa Formation in the Yellowstone Valley, Park County, Montana, and the Colter Formation in Jackson Hole, Teton County, Wyoming. The Hepburn's Mesa Formation was deposited in and adjacent to a perennial saline lake, as shown by the mineral assemblage (clinoptilotite, smectite, calcite, halite, and gypsum) and sedimentary features (fine grain size, laminations, mud cracks, and mud flakes in pebble-sandstone lenses). Biostratigraphic dating indicates that the saline lake formed prior to 16.0 Ma and persisted until after 14.8 Ma. The presence of a saline lake and a fossil mammal fauna dominated by geomyoid rodents indicates an arid or semi-arid climate. Some of the abundant tuffaceous components of the Hepburn's Mesa Formation may have blown from coeval volcanic vents represented by the Colter Formation in Jackson Hole.The Hepburn's Mesa and Colter Formations suggest that both the northern and southern ends of the Greater Yellowstone region were reacting similarly to tectonism during the middle Miocene. (1) Erosion dominated between ca. 18 to 17 Ma. (2) Subsidence of the basins accompanied by extensional block faulting took place from at least 16.0 to 14.8 Ma. (3) After 14.8 Ma but before 8.6 Ma, uplift occurred in northern Yellowstone Park; strata in the Yellowstone Valley and Jackson Hole tilted and eroded, then subsided faster than they had prior to 14.8 Ma. Inasmuch as the chronology of extensional deformation and volcanism in the Greater Yellowstone region is so similar to that in the Northern Rocky Mountains, the Columbia Plateau, and the central part of the Basin and Range, all of these areas appear to be related by a common tectonic process. 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.