Earth Sciences Commons^™

Using Near-Infrared Photography To Better Study Snow Microstructure And Its Variability Over Time And Space, Jesse Raymond Dean

Boise State University Theses and Dissertations

The methods typically used to study snow stratigraphy, microstructure, and variability are expensive, cumbersome, and often highly subjective. Near-infrared (NIR) photography is a low-cost, portable tool to rapidly collect high-resolution, objective measurements of snow microstructure and variability. To expand its application, an active-source NIR flash was introduced to the traditionally passive-source method. NIR imagery was collected alongside proven snowpit methods such as manual observation, Snow Fork wetness, and Snow Micro-Penetrometer hardness profiles. NIR photography was also deployed in five pits along a 10.6 km transect in Grand Mesa, CO, to track stratigraphy variations in space. The NIR flash was found …

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 …

Stratigraphy And Structure Of A South-Trending Structural High, Northern Arkoma Basin, Arkansas, Yirong Chen

Graduate Theses and Dissertations

The Arkoma Basin is a Carboniferous peripheral foreland basin in southeastern Oklahoma and west-central Arkansas. The formation of the Arkoma Basin is a result of a collision between the North American Plate and the Sabine Terrane. To the north of the basin, there is a structural high that extends southward from the Arkoma Shelf into the basin. This structure is in contrast with the prevailing east-trending strike of structures in the northern margin of the basin and is poorly defined. This paper examined the structure of the salient with stratigraphic and structural cross sections. Across the study area, two NS …

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, …

A Synthetic Study To Assess The Applicability Of Full-Waveform Inversion To Infer Snow Stratigraphy From Upward-Looking Ground-Penetrating Radar Data, Lino Schmid, Jürg Schweizer, John Bradford, Hansruedi Maurer

CGISS Publications and Presentations

Snow stratigraphy and liquid water content are key contributing factors to avalanche formation. Upward-looking ground penetrating radar (upGPR) systems allow nondestructive monitoring of the snowpack, but deriving density and liquid water content profiles is not yet possible based on the direct analysis of the reflection response. We have investigated the feasibility of deducing these quantities using full-waveform inversion (FWI) techniques applied to upGPR data. For that purpose, we have developed a frequency-domain FWI algorithm in which we additionally took advantage of time-domain features such as the arrival times of reflected waves. Our results indicated that FWI applied to upGPR data …

Hazard Identification And Coastal Stratigraphy In Crescent Harbor, Northeast Whidbey Island, Washington, Brian Ostrom

All Master's Theses

Crescent Harbor marsh, on northeastern Whidbey Island, records evidence of co-seismic land-level change 1825 to 1925 cal. yrs. BP. The lithostratigraphy and diatom microfossil assemblages reveal a marsh peat abruptly overlain by intertidal mud, indicating rapid subsidence. Analysis of the modern-day position of depositional facies indicates subsidence from a high marsh to a tidal-flat environment representing an estimated 1.7 m elevation change. The timing of subsidence fits within the dates of a rupture found on the nearby Utsalady Point fault between 1,100 and 2,200 years BP (Johnson et al. 2004). Likely, the stratigraphy at Crescent Harbor records the same event …