Geology And Paleoecology Of The Cottonwood Creek Delta In The Eocene Tipton Tongue Of The Green River Formation And A Mammalian Fauna From The Eocene Cathedral Bluffs Tongue Of The Wasatch Formation Southeast Washakie Basin Wyoming

Author : Henry W. Roehler
Publisher :
ISBN 13 :
Total Pages : 20 pages
Book Rating : 4.:/5 (359 download)

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Download or read book Sedimentology of Freshwater Lacustrine Shorelines in the Eocene Scheggs Bed of the Tipton Tongue of the Green River Formation, Sand Wash Basin, Northwest Colorado written by Henry W. Roehler and published by . This book was released on 1990 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two freshwater shorelines are present in the Scheggs Bed of the Tipton Tongue of the Green River Formation along Hardgrove Rim in the Sand Wash basin. The shorelines are part of Lake Gosiute, which occupied southwest Wyoming, northeast Utah, and northwest Colorado during the Eocene Epoch. The rocks comprising the shorelines range in thickness from about 40 feet to 275 feet. They are composed of thick beds of resistant quartzose sandstone, and interbed- ded thin, less resistant conglomerate, siltstone, shale, oil shale, carbonaceous shale, and coal. The shorelines are vertically and horizontally divisible into fluvial channel, mud- flat, swamp, strandline, nearshore, and offshore lithofacies, which are defined by their characteristic lithologies, their sedimentary structures, or both. Each lithofacies can be identified and correlated in the outcrops along Hardgrove Rim. The term shoreline in this report refers to all of the subaerial and subaqueous margins of a lake. The investigations have revealed that the shorelines ·of the Scheggs Bed prograded extensively and that they were entirely wave dominated. They had maximum widths of about 10 miles and probably sloped less than 1 o from back shore areas lakeward to water depths below wave base. Three different environments were present along the shorelines at the land-water interface: (1) strandlines, where there were sand beaches with swash zones; (2) swamps, where vegetation grew in backshore areas out into the lake; and (3) mudflats, where wave erosion caused flooding of parts of the backshore. A columnar section illustrates freshwater lacustrine shoreline deposits that are typical of the Scheggs Bed of the Tipton Tongue and of other tongues and members of the Green River Formation.