Earth Sciences Commons^™

Geomorphology, Stratigraphy, And Paleohydrology Of The Aeolis Dorsa Region, Mars, With Insights From Modern And Ancient Terrestrial Analogs, Robert Eric Jacobsen Ii

Doctoral Dissertations

Ancient fluvial features on Mars evidence past episodes of hydrologic activity and paleoclimate conditions suitable for liquid water. The Aeolis Dorsa region preserves the most numerous and diverse assemblage of fluvial features yet observed on Mars and many of these features have experienced a history of burial, exhumation, and topographic inversion. This dissertation describes analyses of visual images and topography of Mars and complementary analyses of fluvial analogs on Earth. These analyses provide information about the styles of fluvial activity, magnitudes of paleodischarge, changes in slope, and inferences about Martian paleoclimate conditions. Results indicate that the Aeolis Dorsa deposits encapsulate …

Stratigraphy And Depositional Environment Of The Middle Atoka Formation, Central Arkoma Basin, Western Arkansas, Yueyang Wang

Graduate Theses and Dissertations

Wire line logs are widely used in analysis of the subsurface stratigraphy of the middle Atoka Formation, Central Arkoma Basin, Western Arkansas. SP log, Gamma ray log, resistivity log and conductivity log provide valuable information to construct cross sections.

The middle Atoka formation is composed of a succession of shale and sandstone alternations with thickness reaching approximately 3000 feet in the study area. It contains several sandstone units which include Morris, Tackett, Areci, Bynum, Casey and Dunn”A” separated by shale intervals. The purpose of this study is to identify these units and predict sequence stratigraphy and depositional environment by constructing …

On The Importance Of Stratigraphic Control For Vertebrate Fossil Sites In Channel Islands National Park, California, Usa: Examples From New Mammuthus Finds On San Miguel Island, Jeffrey S. Pigati, Daniel R. Muhs, John P. Mcgeehin

United States Geological Survey: Staff Publications

Quaternary vertebrate fossils, most notably mammoth remains, are relatively common on the northern Channel Islands of California. Well-preserved cranial, dental, and appendicular elements of Mammuthus exilis (pygmy mammoth) and Mammuthus columbi (Columbian mammoth) have been recovered from hundreds of localities on the islands during the past half-century or more. Despite this paleontological wealth, the geologic context of the fossils is described in the published literature only briefly or not at all, which has hampered the interpretation of associated 14C ages and reconstruction of past environmental conditions. We recently discovered a partial tusk, several large bones, and a tooth enamel plate …

Stratigraphy Of The Upper Devonian-Lower Mississippian Michigan Basin: Review And Revision With An Emphasis On The Ellsworth Petroleum System, Bryan J. Currie

Masters Theses

Compression associated with the formation of the Transcontinental Arch and the Acadian Mountains initiated subsidence in the Michigan Basin and lead to a depositional switch in the Michigan Basin from an oxic shallow-water carbonate platform (Traverse Group and Squaw Bay Limestone) to a deep anaerobic sea floor and the beginning of Upper Devonian Antrim Shale. The vertical distribution of the different Upper Devonian-Lower Mississippian formations and members demonstrates large scale cycles of anaerobic-dysaerobic transitions attributed fluctuations in sea-level, different rates of subsidence and sediment influx triggered by different orogenic events to.

The regional understanding and the distribution of the different …

Sedimentology And Stratigraphy Of The Middle Jurassic Preuss Sandstonein Northern Utah And Eastern Idaho, Preston Scott Cook

Theses and Dissertations

The purpose of this study is to analyze the sedimentology and stratigraphy of the Middle Jurassic Preuss Sandstone and re-evaluate past sedimentological interpretations. The Preuss is located in northern Utah, western Wyoming and eastern Idaho and is stratigraphically equivalent to the Entrada Sandstone, which is Callovian in age (Dossett et al., 2014). This study is the first attempt at 1) a sequence stratigraphic framework, 2) a petroleum system analysis and 3) an extraterrestrial analog study for the Preuss. This study frames the Preuss within three broad facies groups: marine, coastal and terrestrial. The marine group includes the open marine and …

Preliminary Correlation And Isopach Map Of Navajo-Aztec-Nugget Sandstones, Western United States, Emily Jackson

The Research and Scholarship Symposium (2013-2019)

Lower and middle Jurassic sandstones across western North America were correlated using stratigraphic thickness and lithofacies data obtained from the AAPG-produced Correlation of Stratigraphic Units of North America (COSUNA) data charts and spreadsheets. An isopach map and a series of stratigraphic cross-sections were created to display the lateral and horizontal extent of the correlated formations. The goal was to determine lateral equivalents of the primarily lower Jurassic Navajo Sandstone from Utah, Arizona, and Colorado. The Nugget Sandstone of Wyoming, Utah, and southern Idaho, and the Aztec Sandstone of southeastern California and southern Nevada were determined to be laterally equivalent to …

Correlation Of Basal Cambrian Sandstones Across North America, Joshua W. Perez

The Research and Scholarship Symposium (2013-2019)

A thin, widespread sequence of siliciclastic strata ranging from lower to upper Cambrian age overlies Precambrian crystalline and metamorphic basement rock bounded by the Great Unconformity. This sequence is mainly comprised of basal Cambrian sandstones which can be subdivided into three distinct suites of lithofacies transitioning in age across most of North America. From the west, which is most notable for the Tapeats sandstone of Arizona and Nevada, lies gravelly to boulder sized conglomerates directly overlying basement rock. Eastward, the lower to middle Cambrian consists of a variety of ledge-forming sandstones which contain various areas rich in cross bedded, as …

A History Of African And South American Basins, Rebecca A. Bobick

Open Access Theses

As hydrocarbon development in Africa and South America continues to expand, understanding the geologic evolution as well as the geologic symmetry of each of the continent's coastal basins grows increasingly important. Unfortunately, there's currently no comprehensive database that contains the stratigraphic record, depositional environments, and tectonic evolution available for either Africa or South America. Therefore, the goal of my research is to create an extensive datapack and guide booklet for Africa's major sedimentary basins, complete the South America datapack that's currently being constructed, and correlate the western African conjugate basins to the eastern South American conjugate basins. To accomplish this, …