Physical Sciences and Mathematics Commons^™

Structure And Petrology Of Tertiary Volcanic Rocks In Parts Of Toms Cabin Spring And Lucin Nw Quadrangles (Box Elder Co.), Utah, Bruce Edward Scarbrough

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A series of late Tertiary rhyolitic and dacitic flows, domes, and minor pyroclastic rocks form an elongate volanic mass along the northwestern Utah-northeastern Nevada border. The structure of the flow banding and the linear arrangement of vents indicate that the mass represents a multi-sourced extrusive complex which erupted through many fissure-type conduits. A 39 km² area at the southern end of the mass was studied in detail in order to gain a better understanding of the eruptive nature and history of these Tertiary volcanic rocks. Age dating reveals that volcanism in the study area was episodic, and covered a …

Petrology Of The Middle Jurassic Twin Creek Limestone, Lincoln And Sublette Counties, Southwestern Wyoming, David R. Raubvogel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Twin Creek Limestone of Middle Jurassic age was studied in the Tunp, Salt River, and Wyoming Ranges in southwestern Wyoming. Modern carbonate environments and their ancient analogs were compared with information obtained from field study and petrographic analysis of samples of the Twin Creek Limestone in order to delineate environments of deposition, paleogeography, and diagenetic history.

Six major lithofacies were recognized: (1) carbonate mudstone; (2) carbonate mudstone breccia; (3) fossiliferous wackestone; (4) packstone-grainstone; (5) terrigenous mudstone; and (6) sandstone. These lithofacies were deposited in a variety of environments, including outer shelf platforms (carbonate mudstone and fossiliferous wackestone), oolitic sand …

Petrology Of The Middle Cambrian Ute Formation, North-Central Utah And Southeastern Idaho, Edward James Deputy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Cambrian Ute Formation was studied in the Bear River Range and the Wellsville Mountains of north-central Utah and southeastern Idaho. The depositional textures and sedimentary structures found within the rocks were compared with similar modern sediments and ancient rocks to determine depositional environments, paleogeography, and diagenetic alterations.

The rocks of the Ute Formation were divided into five basic types. These five rock types were formed within four identifiable lithofacies: 1) elastic marine shelf; 2) carbonate marine shelf; 3) agitated shoal; and 4) quiet-water shoal.

The sequence of elastic and carbonate sediments is believed to have been deposited in …