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Subsurface Correlation Of Lower Silurian Medina Group, Southwestern Ontario, Rhys H. Paterson

Electronic Thesis and Dissertation Repository

The Medina Group succession in southwestern Ontario includes, in ascending order: the Whirlpool, Manitoulin, Cabot Head, Power Glen, Devils Hole-Balls Falls, Grimsby, and Thorold formations. Subsurface mapping in central and eastern Lake Erie has resulted in the recognition of three stratigraphic packages within the Medina Group based upon the integration of sedimentologic, stratigraphic and geophysical borehole logs. The interplay between changing paleoenvironments, sediment provenance, and regional tectonics and associated sea level fluctuations has resulted in the accumulation of a complex mosaic of mixed siliciclastics and carbonates. Manitoulin Formation carbonates and Whirlpool Formation siliciclastics display consistent thicknesses across the study area. …

Facies And Diagenesis Analyses Of The Fort Terrett Formation Of The Lower Cretaceous Edwards Group, Near Junction, Texas, Richard Alden Urwin Jr.

Electronic Theses and Dissertations

The Fort Terrett Formation was deposited on the western edge of the Comanche Shelf in central Texas. The predominate lithology of the Fort Terrett Formation is limestone which caps the hills that surround Junction, Texas. Deposition of the Fort Terrett Formation occurred within shallow, quiet waters during the Lower Cretaceous. Rose (1974) developed a general stratigraphic correlation and lithostratigraphic framework for the Cretaceous Shelf and established a regional correlation. Four stratigraphic divisions have been recognized in the Fort Terrett Formation. These are: a basal nodular unit, a burrowed unit, a dolomitic unit, and the Kirschberg evaporites. Wilkerson (2018) provided the …

A Structural And Stratigraphic Study Of The A-2 Carbonate In Southwest Michigan And Reservoir Characterization Of An A-2 Carbonate Gas Storage Field, Clayton Joupperi

Masters Theses

The Overisel and Salem gas storage fields of southwest Michigan annually store 34 Bcf of natural working gas in the upper dolomitized portion of the Silurian A-2 Carbonate. Porosity and permeability in these fields is thought to be enhanced by fracturing and dolomitization associated with the dissolution and collapse of underlying salt units. This study utilizes wire-line logs from 383 wells to explore the structural and stratigraphic controls on the deposition and diagenesis of the A-2 Carbonate in southwest Michigan. Core and thin sections from 4 wells serve as the primary data for investigating the depositional and diagenetic history of …

Twentieth Century Channel Change Of The Green River In Canyonlands National Park, Utah, Alexander E. Walker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since the early 20^th century, river channels of the Colorado River basin have narrowed, decreasing available riparian and aquatic habitat. Changes are considered to be the result of three major factors: wide-spread water development, increasing hydroclimate variability and the invasion of non-native tamarisk (Tamarix spp.), altering flow regime and sediment supply. Different studies have reached different conclusions about the relative roles of flow regime, sediment supply and tamarisk in causing narrowing.

I investigated channel change in the lower Green River within Canyonlands National Park to describe channel changes in the 20^th century and understand the roles …

Stratigraphy Of The Middle Cambrian Lincoln Peak Formation And Evolution Of The House Range Embayment, Eastern Nevada, Ibrahim Zallum

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This study examined the Middle Cambrian (c. 500 MA) Lincoln Peak Formation and Patterson Pass Shale. The initial goal was to create a stratigraphic model for these units. This model was then compared to those from already studied units in western Utah, which combined with the Nevada units form the rock record of an ancient feature known as the House Range Embayment, which was an area of greater water depth superimposed on the continental shelf. This study found that the Nevada units exhibit a series of depositional sequences similar to those in western Utah, but at a lower resolution. This …

Using The Past As The Key To The Present: Informing Coastal Resource Management With Geologic Records, Benjamin D. Dejong

Graduate College Dissertations and Theses

Rising sea levels present an ongoing threat to communities and resources around the Chesapeake Bay, east coast, USA, where tide gauges indicate that the relative rise of sea level is approximately twice the rate of average, eustatic sea-level rise. This has significantly compromised the health and viability of salt marsh habitat on the Eastern Shore during the 20th century, and the biologists who are charged with managing coastal resources in the coming decades need to understand the nature and causes of high rates of regional sea-level rise to develop suitable adaptation plans.

Dated geologic deposits and geophysical models suggest that …