Stratigraphy of the Willwood and Tatman formations in northwestern Wyoming

Abstract

Research Article| February 01, 1944 Stratigraphy of the Willwood and Tatman formations in northwestern Wyoming FRANKLYN B. VAN HOUTEN FRANKLYN B. VAN HOUTEN Search for other works by this author on: GSW Google Scholar Author and Article Information FRANKLYN B. VAN HOUTEN Publisher: Geological Society of America Received: 03 Aug 1942 First Online: 02 Mar 2017 Online Issn: 1943-2674 Print Issn: 0016-7606 © 1944 Geological Society of America GSA Bulletin (1944) 55 (2): 165–210. https://doi.org/10.1130/GSAB-55-165 Article history Received: 03 Aug 1942 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation FRANKLYN B. VAN HOUTEN; Stratigraphy of the Willwood and Tatman formations in northwestern Wyoming. GSA Bulletin 1944;; 55 (2): 165–210. doi: https://doi.org/10.1130/GSAB-55-165 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 formation name Willwood is proposed for variegated shales and hornblende-bearing sand stones conformably overlying the Polecat Bench formation near the center of the Big Horn Basin Wyoming, and truncating folds along the western margin of the area. Willwood sediments were deposited in a forested lowland, under warm-temperate conditions. Sinking of the structural basin was slower than Willwood deposition for upper Willwood deposits spread laterally beyond the lower part of the formation. Pre-Cambrian pebbles in both Polecat Bench and Willwood conglomerates indicate erosion of the pre-Cambrian cores of the uplifts surrounding the Big Horn Basin during late Paleocene and early Eocene time. Locally, the Willwood yields Clark Fork (Late Paleocene) mammals. Above the Clark Fork beds Willwood deposits contain mammals characteristic of the Early Eocene (Wasatchian).The Tatman formation (early Bridgerian) lies conformably upon the Willwood and below the basic breccia capping Squaw Buttes. It consists of about 870 feet of alternating fine-grained sandstone and laminated brown carbonaceous shale, swamp and lake deposits which accumulated under conditions analogous to those that produced the shore facies of the Green River formation.Late Cretaceous and early Cenozoic orogenic movements effected no pronounced change in the topography or in the climate of the Big Horn Basin. 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.