Browsing by Author "Steltenpohl, Mark"

Now showing items 1-20 of 28

40Ar/39Ar Ages of Muscovite from the Western Blue Ridge and Talladega Belt, Georgia and North Carolina

McDonald, Wayne (2008-05-15)

Radiometric age constraints regarding the timing of metamorphism in the western Blue Ridge province of the southern Appalachians have been too limited or uncertain to enable broader correlation and understanding of Taconian, ...

An analysis of sediment provenance for Carboniferous sandstones in the Ouachita-Arkoma Basin based on detrital muscovite 40Ar/39Ar geochronology and sediment composition

Thompson, Jacob (2019-12-04)

The Arkoma-Ouachita Basin of southeast Oklahoma and central Arkansas, part of the vast Appalachian-Ouachita foreland system, evolved from a passive margin deep-water remnant ocean basin (Ouachita) between Laurentia and ...

Characterizing Subsurface Structural Features of the Bellingham Basin by Gravity and Magnetic Modeling

Bhattacharya, Rahul (2019-08-15)

This study uses gravity and magnetic data modeling to identify the geometry of the Bellingham basin, Washington, and its deformational history. The study also provides additional insight into three newly identified ...

Clustered Seismicity in Alabama: Natural or Anthropogenic?

Chen, Jian (2017-07-27)

Seismicity in the central and eastern U.S. is typically characterized by low-magnitude earthquakes (M < 4) with a random distribution that occur in areas of low to moderate strain rates. An unprecedented increase in ...

Evidence for Deformation and Faulting in the Muckleshoot basin, Washington

Cox, Justin (2015-05-05)

The Muckleshoot basin of Western Washington state extends from the western base of the Cascades to approximately 10 km east of the Puget Sound. Mapped traces of the Tacoma and White River fault systems, to the west and ...

An Examination of Metamorphic Uranium Occurrences in Coosa County, Alabama

Horwitz, Jessica (2010-07-06)

Coosa County, Alabama, is host to one or more presumably metamorphosed uranium occurrences of unknown size or grade. The exact location, size and mode of emplacement of each uranium occurrence is currently unknown. This ...

Exhumation History of Caledonian Eclogites in Liverpool Land, East Greenland, and Comparisons with Eclogites in Norway

Bowman, Dannena (2008-05-15)

Lithologic information and 40Ar/39Ar cooling dates are reported from a recently discovered high-pressure (HP) Caledonian eclogite terrane in Liverpool Land, East Greenland, its overlying hanging wall block, and an extensional ...

Geochemistry and Mineralogy of Eastern Ag-Rich Epithermal Veins in the Midas District, Nevada, USA

Chitwood, Rue (2012-04-09)

Five Ag-rich epithermal veins were recently discovered in the eastern section of the Midas district in northern Nevada. Initial data collected indicated that these veins had a significantly higher quantity of silver relative ...

Geology of the 1:24,000 Roanoke East Quadrangle and investigations of the Long Island Creek Gneiss within the southernmost Appalachians, Alabama and Georgia

Harstad, Rylleigh (2017-07-22)

The geology of the 1:24,000 Roanoke East, Alabama, Quadrangle has been determined to be of high mapping priority by the State Geologic Mapping Advisory Committee due to the rapid development along the I-85 corridor west ...

Geology of the 1:24,000 Tallassee, Alabama, Quadrangle, and its Implications for Southern Appalachian Tectonics

White, Thomas (2008-05-15)

The 1:24,000 scale Tallassee, Alabama, Quadrangle, was mapped to characterize lithologies and structures in the southernmost exposures of the southern Appalachians. Four deformation events are recognized. D1 was associated ...

Geology of the Alexander City 7.5’ Quadrangle, Alabama and U-Pb Zircon Dating of the Elkahatchee Quartz Diorite, southernmost Appalachian orogen

Weinmann, Benjamin (2019-04-26)

Geological mapping of the Alexander City Quadrangle in the eastern Blue Ridge of the Southern Appalachian orogen in Alabama reveals newly recognized units and supports multi-phase magmatism within the 880 km2 Elkahatchee ...

Geology of the Farmville Metagranite and Associated Units as Exposed at the Notasulga Quarry, Notasulga, Alabama

Bogdan, Kevin (2009-07-21)

Predicting the locations and thicknesses of aggregate-affable lithologies (ore units), interburden (non-ore material between ore-units), and overburden (overlying soil/saprolite) on a local level is critical for developing ...

Geology of the Jacksons Gap, Alabama, 7.5-Minute Quadrangle: Implications for the Evolution of the Brevard Fault Zone

Poole, Joshua (2015-05-11)

The Brevard fault zone is a major Appalachian structure that marks the boundary between the eastern Blue Ridge (EBR) and the Dadeville Complex (DC) of the Inner Piedmont (IP) terrane in Alabama. Despite over a century of ...

Geology of the Milltown Alabama 7.5’ Quadrangle and 40Ar/39Ar geochronology of muscovite from select rocks of the east-central Alabama Piedmont

Whitmore, John (2018-12-13)

The Milltown 7.5’ Quadrangle is located within east-central Alabama and contains features important to understanding the formation of the southern Appalachians. The Brevard fault zone passes through the Milltown Quadrangle ...

Geology of the Southernmost Exposures of the Brevard Zone in the Red Hill Quadrangle, Alabama

Sterling, Wes (2006-12-15)

The southernmost exposures of the Brevard zone were mapped to characterize its lithologic makeup and structural character and to explore its significance to the tectonic evolution of the southernmost Appalachians. Two ...

Gravity and magnetic modeling of basement beneath the Appalachian Plateau, Valley and Ridge, and Piedmont provinces, Alabama

Singleton, Robert III (2016-07-18)

Despite the significance of regional geophysical anomalies and the economic potential of the area, central Alabama has lacked detailed crustal gravity and magnetic models. The southeastern United States has undergone at ...

The Late- to Post-Caledonian Extensional History of Northwest Hinnoy, North Norway

Mager, Stephanie (2005-08-15)

This investigation focuses on the lithologies and late- to post-Caledonian, upper crustal structures exposed in westernmost Hinnoy, north Norway, and the information about the timing and kinematics of faults that they may ...

Linking Observed Seismicity to Crustal Structure in the New Madrid Seismic Zone Using Gravity and Magnetic Modeling

Eldridge, Caleb (2019-07-23)

The New Madrid Seismic Zone in the Central United States is a highly active seismic zone. Research has focused on the subsurface structure and history of development in order to gain better insight into the cause of these ...

Magma evolution and processes of the Ashi Volcano, NW Tibet, China: Sr isotope studies of plagioclase crystals

Speetjens, Sara (2018-04-27)

The Ashi Volcano is a member of the Ashikule Volcanic Field (AVF) and is located on the northwestern margin of the Tibetan Plateau. The Ashi Volcano draws much attention from volcanologists due to its recent eruptions in ...

Petrographic Investigation of Selected Samples from Drill Cores Eyreville A and Eyreville B: Chesapeake Bay Impact Structure, Virginia

Glidewell, Jennifer (2008-05-15)

The meteoritic impact process is expressed uniquely in marine, sedimentary target impact structures versus hard, dry crystalline targets. Wet sediments accommodate extreme pressures and temperatures differently than ...