Reef Creek Detachment Fault, Northwestern Wyoming

Abstract

Research Article| October 01, 1963 Reef Creek Detachment Fault, Northwestern Wyoming WILLIAM G PIERCE WILLIAM G PIERCE U. S. Geological Survey, Menlo Park, Calif Search for other works by this author on: GSW Google Scholar Author and Article Information WILLIAM G PIERCE U. S. Geological Survey, Menlo Park, Calif Publisher: Geological Society of America Received: 27 Dec 1962 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1963, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1963) 74 (10): 1225–1236. https://doi.org/10.1130/0016-7606(1963)74[1225:RCDFNW]2.0.CO;2 Article history Received: 27 Dec 1962 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 WILLIAM G PIERCE; Reef Creek Detachment Fault, Northwestern Wyoming. GSA Bulletin 1963;; 74 (10): 1225–1236. doi: https://doi.org/10.1130/0016-7606(1963)74[1225:RCDFNW]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 Reef Creek fault is in northwestern Wyoming, a few miles east of the northeast border of Yellowstone National Park. It lies within the area covered by the more extensive Heart Mountain fault. Like that fault, it is a décollement or detachment fault in which strata became detached along a basal shearing plane and moved laterally on a slightly inclined fault surface. At the most northwesterly exposures the Reef Creek fault parallels the bedding; southeastward it cuts upward across the bedding as a transgressive fault and becomes a fault in which the allochthonous blocks moved on the surface of the ground. The fault blocks consist chiefly of the Madison Limestone of Mississippian age and volcanic tuffs and breccias of the Cathedral Cliffs Formation of early or middle Eocene age. The Reef Creek fault blocks are scattered over a 7- by 14-mile area, but a considerable part of the scattering is due to "piggy-back" transportation on the Heart Mountain fault blocks.The Reef Creek fault is younger than the Cathedral Cliffs Formation and older than the middle Eocene early basic breccia. Consequently, the rocks transported by it were emplaced either in late early Eocene or in early middle Eocene time. Both the Reef Creek fault and the South Fork fault are older than the principal movement along the Heart Mountain fault. The movement of all three fault masses was southeastward, and the mechanics of their emplacement is believed to have been similar. Movement was due in part to gravity, but considering the low slope involved, gravity alone seems to be inadequate. The shaking motion of many earthquakes is suggested as a contributing force which acted in conjunction with the constant force of gravity. 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.