Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Physical Sciences and Mathematics
Surficial Deposits And Geologic History, Northern Bear Lake Valley, Idaho, George C. Robertson Iii
Surficial Deposits And Geologic History, Northern Bear Lake Valley, Idaho, George C. Robertson Iii
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Detailed geologic mapping and subsurface study of late Pleistocene and Holocene sediments in northern Bear Lake Valley show at least four episodes of deposition of fluvial, marsh, bay, and lacustrine sediments. from oldest to youngest, these are the Ovid, Liberty, Wardboro, and Lifton episodes. These episodes are substantially different than those proposed by previous investigators. The informal term Bear Lake Formation is formally redefined here as the Bear Lake Group, and includes the newly defined Ovid Formation, Liberty Formation, Lanark Formation, and Rainbow Gravel. The overlying Wardboro Loess, also defined here, provides a probably age of 11,000 to 8,000 years …
Autecology Of Selected Genera Of Mississippian, Permian And Triassic Ammonoids: Analysis Of Coiling Geometries, Edward Ellis Chatelain
Autecology Of Selected Genera Of Mississippian, Permian And Triassic Ammonoids: Analysis Of Coiling Geometries, Edward Ellis Chatelain
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Ammonoids were collected from the Chainman Formation (Mississippian) of southeastern Nevada and southwestern Utah, the Phosphoria Formation (Permian) of southeastern Idaho and westernmost Wyoming, and the Thaynes Formation (Triassic) of northeastern Nevada and southeastern Idaho. The collections are interpreted to represent unwinnowed, untransported death assemblages of ammonoids which were subject to chemical conditions of the nekto-benthic environment. Associated lithologies were sampled and geochemically analyzed for content of phosphate and organic matter. Ammonoid fossil collections, combined with ammonoids illustrated in the literature, were subjected to the graphical W and D analysis of Raup (1967). The basic parameters involved in the description …