Fourth-order nonmarine to marine sequences, middle Castlegate Formation, Book Cliffs, Utah

Abstract

Research Article| April 01, 2000 Fourth-order nonmarine to marine sequences, middle Castlegate Formation, Book Cliffs, Utah Brett T. McLaurin; Brett T. McLaurin 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar Ron J. Steel Ron J. Steel 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar Geology (2000) 28 (4): 359–362. https://doi.org/10.1130/0091-7613(2000)28<359:FNTMSM>2.0.CO;2 Article history received: 22 Oct 1999 rev-recd: 18 Jan 2000 accepted: 26 Jan 2000 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 Brett T. McLaurin, Ron J. Steel; Fourth-order nonmarine to marine sequences, middle Castlegate Formation, Book Cliffs, Utah. Geology 2000;; 28 (4): 359–362. doi: https://doi.org/10.1130/0091-7613(2000)28<359:FNTMSM>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 SocietyGeology Search Advanced Search Abstract The lower part of the Campanian Castlegate Formation, one of the best known fluvial sheet sands of the Western Interior seaway, combines with an overlying finer grained unit (middle member of the Castlegate Formation) to form an unconformity-bounded, third-order stratigraphic sequence (∼3 m.y. duration). This sequence contains a mappable muddy zone along the western Book Cliffs of Utah now mapped as contiguous with the open-marine parts of the succession (Buck Tongue, Sego Sandstone, Anchor Mine Tongue) to the east. The correlation within the middle Castlegate has been refined and the nature of the link between tidally influenced fluvial strata in the west and marine strata in the east has been remapped. Five high-frequency stratigraphic sequences (all within the upper part of the larger third-order sequence), forming a thickness to 160 m, have been mapped in the Price area southeastward into the time-equivalent marine succession near Green River. Individual sequences (probably <0.5 m.y. duration), reflecting transgressive to regressive estuary infilling, have an internal architecture in which fluvial and tidally influenced distributary-channel belts pass up into muddy central-basin sedimentary units, to bayhead-delta deposits, and in some places up to more fluvial channel belts. The key to the mapping of individual sequences is recognition of the muddy, brackish-water interval, developed during maximum transgression of the time-equivalent shoreline. The two most proximal marine-influenced sequences (2 and 3) are probably broadly time-equivalent with the Buck and Anchor Mine Tongues to the east. The analysis here, contrary to recent suggestions, shows that the marine sequences in the eastern Book Cliffs can be traced far into the time-equivalent, western fluvio-estuarine succession. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.