Cathedral Cliffs Formation, the Early Acid Breccia Unit of Northwestern Wyoming

Abstract

Research Article| January 01, 1963 Cathedral Cliffs Formation, the Early Acid Breccia Unit of 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: 24 Apr 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 (1): 9–22. https://doi.org/10.1130/0016-7606(1963)74[9:CCFTEA]2.0.CO;2 Article history Received: 24 Apr 1962 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation WILLIAM G PIERCE; Cathedral Cliffs Formation, the Early Acid Breccia Unit of Northwestern Wyoming. GSA Bulletin 1963;; 74 (1): 9–22. doi: https://doi.org/10.1130/0016-7606(1963)74[9:CCFTEA]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 name Cathedral Cliffs Formation is proposed for the rocks in the Clarks Fork area of northwestern Wyoming that have long been known by the informal designation “early acid breccia.” In the Clarks Fork area the Cathedral Cliffs Formation is composed of tuffs, with lesser amounts of volcanic sedimentary rocks and breccias. Its thickness ranges from less than 100 feet to about 1500 feet but more commonly is 500–900 feet. The formation is tentatively considered to be late early Eocene or early middle Eocene. It is underlain by rocks ranging from Precambrian to early Eocene(?) and is overlain unconformably by the early basic breccia of middle Eocene age.Low-angle detachment faulting, which involved the Cathedral Cliffs Formation but not the overlying early basic breccia, has made recognition and correlation of the formation difficult. Blocks and masses of Madison Limestone of Mississippian age were emplaced locally on its upper surface by the Reef Creek detachment fault. The Cathedral Cliffs Formation and the Paleozoic carbonate rocks beneath it, as well as the Reef Creek fault masses on its surface, were then transported southeastward by the Heart Mountain detachment fault. As movement on the Heart Mountain detachment proceeded, the large fault mass broke up into smaller blocks, which separated as movement continued. Consequently the Cathedral Cliffs Formation was distributed in a pattern which gives the appearance of isolated occurrences and erosional remnants. The detached blocks of the Reef Creek fault on the upper surface of the Cathedral Cliffs also were scattered more widely than by their original movement on the Reef Creek fault. Soon after the fault-transported segments of the Cathedral Cliffs Formation ceased moving they were buried beneath the early basic breccia. The unconformity between the early acid breccia and the early basic breccia is thus substantiated in the Clarks Fork area; in the time interval represented, the Reef Creek and Heart Mountain fault masses were emplaced.The Cathedral Cliffs Formation is correlated with the early acid breccia in northern Yellowstone National Park and the upper part of the Reese Formation as mapped by Calvert west of Gardiner, Montana. The volcanic-source area probably is not in the central Yellowstone Park region, but somewhere to the north. 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.