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Full-Text Articles in Geology

An Iterative Approach To Ground Penetrating Radar At The Maya Site Of Pacbitun, Belize, Sheldon Skaggs, Terry G. Powis, Clara R. Rucker, George Micheletti Sep 2016

An Iterative Approach To Ground Penetrating Radar At The Maya Site Of Pacbitun, Belize, Sheldon Skaggs, Terry G. Powis, Clara R. Rucker, George Micheletti

Publications and Research

Ground penetrating radar (GPR) surveys provide distinct advantages for archaeological prospection in ancient, complex, urban Maya sites, particularly where dense foliage or modern debris may preclude other remote sensing or geophysical techniques. Unidirectional GPR surveys using a 500 MHz shielded antenna were performed at the Middle Preclassic Maya site of Pacbitun, Belize. The survey in 2012 identified numerous linear and circular anomalies between 1 m and 2 m deep. Based on these anomalies, one 1 m × 4 m unit and three smaller units were excavated in 2013. These test units revealed a curved plaster surface not previously found at …


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 Sep 2016

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 …


Montauk Point, An Essential Field Experience For Students In The New York City Area, Stanley Schleifer, Nazrul I. Khandaker, Keshaw Narine Sep 2016

Montauk Point, An Essential Field Experience For Students In The New York City Area, Stanley Schleifer, Nazrul I. Khandaker, Keshaw Narine

Publications and Research

Except for a thin strip of Proterozoic and Paleozoic metamorphic and igneous rock along its very western edge and an outcropping of coastal plain deposits along its northwestern edge, the surface of Long Island is immediately underlain by unconsolidated deposits consisting of moraines of glacial till, outwash plains of stratified drift, and beach and dune complex formed by wave action. Two very prominent features of the island are the Harbor Hill Moraine, which marks the southernmost extent of the last major advance of continental glacier ice in the New York area during the Pleistocene and the Ronkonkoma Moraine, which marks …


Surficial Geology Of York College Campus (Queens) And Montauk Point (Long Island): An Open Access To Geoscience Education, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Erik Menjivar, Ality Aghedo, Dennis Baidoo, Tenzin Choeying, Vanessa Erwin, Jonathan Xavier, Laboni Molla, Akeed Alrubay Sep 2016

Surficial Geology Of York College Campus (Queens) And Montauk Point (Long Island): An Open Access To Geoscience Education, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Erik Menjivar, Ality Aghedo, Dennis Baidoo, Tenzin Choeying, Vanessa Erwin, Jonathan Xavier, Laboni Molla, Akeed Alrubay

Publications and Research

To evaluate compositional and textural differences among the samples collected from York College (YC) campus (Queens), Montauk Point (MP) and Hither Hills (HH), Long Island, emphasis is given to the general geologic setting, overall grain size distribution, and relative abundances of light and heavy mineral assemblages. Geologic setting encompasses outwash plains (York College), fluvioglacial and glacial (Montauk Point) and beach and dune complex (Hither Hills). YC samples were collected from depth ranging 40 cm to 250 cm and are mostly an assortment of medium to coarse sand, granule to cobble sized, minor silt, and clay. Presence of low angle cross …


Experiential Learning Opportunities Through Nasa Stem Content Allows Greater Grass Root-Level Understanding Of The Present Day’S Extreme Climate Change Scenario, Nazrul I. Khandaker, Stanley Schleifer, Matthew Khargie Sep 2016

Experiential Learning Opportunities Through Nasa Stem Content Allows Greater Grass Root-Level Understanding Of The Present Day’S Extreme Climate Change Scenario, Nazrul I. Khandaker, Stanley Schleifer, Matthew Khargie

Publications and Research

The NASA MAA (MUREP Aerospace Academy) project at York College has demonstrated a track record of providing experiential learning opportunities (ELO) to its participating students. ELOs associated with MAA are designed to increase learners’ involvement, knowledge, comprehension and application of learning in one or more STEM subjects/disciplines. They involve inquiry-and-activity-based learning approaches designed for the level of the learner to inspire, engage, and educate while progressively challenging each student. ELO activities enable learners to acquire knowledge, understand what they have learned, and apply that knowledge through inquiry-based tasks. Specifically, we are prepared to address the following priority: Encourage, increase, and …


Effective Integration Of Nasa Stem Curricula Is Allowing Students To Appreciate Earth Science Concepts, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Newrence Wills, Matthew Khargie Sep 2016

Effective Integration Of Nasa Stem Curricula Is Allowing Students To Appreciate Earth Science Concepts, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Newrence Wills, Matthew Khargie

Publications and Research

NASA Minority University Research and Education Project (MUREP) Aerospace Academy - MAA is a national, innovative activity designed to increase participation and retention of historically underserved and underrepresented K-12 youth in the STEM disciplines, particularly earth science and human exploration (HEO). HEO is dedicated to informing and educating the public about NASA's plans for a new era in space exploration. Utilization of NASA satellite images, online climate education, space mathematics and other earth science-related resources is allowing students to conduct basic research and prepare themselves for a New York City-wide science competition. In addition to offering school children a solid …


Birth And Evolution Of The Rio Grande Fluvial System In The Last 8 Ma:Progressive Downward Integration And Interplay Between Tectonics, Volcanism, Climate, And River Evolution, Marisa N. Repasch Sep 2016

Birth And Evolution Of The Rio Grande Fluvial System In The Last 8 Ma:Progressive Downward Integration And Interplay Between Tectonics, Volcanism, Climate, And River Evolution, Marisa N. Repasch

Earth and Planetary Sciences ETDs

The Rio Grande-Rio Chama (RG-RC) fluvial system has evolved dramatically over the last 8 Ma, undergoing channel migrations, drainage capture and integration events, volcanic damming, and carving and refilling of paleocanyons. Volcanism concurrent with the development of the river system provides a unique opportunity to apply multiple geochronometers to the study of its incision and drainage evolution. This paper reports 19 new 40Ar/39Ar basalt ages and 19 detrital mineral samples (zircon and sanidine) collected from RG-RC alluvium overlain by dated basalt flows in the context of a compilation of published 40Ar/39Ar basalt ages. The …


Possible Recent Warming Hiatus On The Northwestern Tibetan Plateau Derived From Ice Core Records, Wenling An, Shugui Hou, Wangbin Zhang, Shuang-Ye Wu, Hao Xu, Hongxi Pang, Yetang Wang, Yaping Liu Sep 2016

Possible Recent Warming Hiatus On The Northwestern Tibetan Plateau Derived From Ice Core Records, Wenling An, Shugui Hou, Wangbin Zhang, Shuang-Ye Wu, Hao Xu, Hongxi Pang, Yetang Wang, Yaping Liu

Department of Earth, Environment and Sustainability Faculty Publications

Many studies have reported enhanced warming trend on the Tibetan Plateau (TP), even during the warming hiatus period. However, most of these studies are based on instrumental data largely collected from the eastern TP, whereas the temperature trend over the extensive northwestern TP remains uncertain due to few meteorological stations. Here we combined the stable isotopic δ18O record of an ice core recovered in 2012 from the Chongce glacier with the δ18O records of two other ice cores (i.e., Muztagata and Zangser Kangri) in the same region to establish a regional temperature series for the northwestern …


Co2 Sequestration Test In A Deep, Unminable Lignite Seam, University Of North Dakota. Energy And Environmental Research Center Sep 2016

Co2 Sequestration Test In A Deep, Unminable Lignite Seam, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet describing results of a Plains CO2 Reduction (PCOR) Partnership-implemented test to determine the possibility of storing CO2 in unminable lignite seams. Discusses testing procedure and purpose, and summarizes key results. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Compositional Diversity In Arcs: A Record Of Magmatic Processes In The Peru Coastal Batholith, Ica, Ana Maria Martinez Ardila Sep 2016

Compositional Diversity In Arcs: A Record Of Magmatic Processes In The Peru Coastal Batholith, Ica, Ana Maria Martinez Ardila

Loma Linda University Electronic Theses, Dissertations & Projects

Peruvian granitic plutons display evidence for crustal recycling and magma mixing. Evidence of physical and chemical processes operating during the formation of the Ica-Pisco complexes involves magma mixing and mingling as result of felsic and mafic interactions. Evidence of crustal recycling was identified from kilometer-scale cauldron subsidence, meter and centimeter-scale -stoping, and disaggregation. At the petrographic microscope scale, evidence for recycling and mixing between mantle and crustal magma during crystallization is found from disequilibrium features such as reaction rims, resorbed cores, and patchy zoning. Elemental and isotope geochemistry data indicate that mantle magmas have incorporated continental crust material from varying …


Natural And Anthropogenic Sources Of Arsenic And Nitrate In A Semi-Arid Alluvial Basin; Goshen Valley, Utah, Brian John Selck Sep 2016

Natural And Anthropogenic Sources Of Arsenic And Nitrate In A Semi-Arid Alluvial Basin; Goshen Valley, Utah, Brian John Selck

Theses and Dissertations

Arsenic (As) and nitrate (NO3) are common contaminants in groundwater that are introduced through a variety of natural and anthropogenic sources. In this study we investigated the sources and distribution of As and NO3 in Goshen Valley, Utah, USA. Goshen Valley is a semi-arid alluvial basin that is impacted by geothermal waters, agriculture, urban development, and legacy mining. In this study we sampled surface water, springs, and wells to analyze concentrations of major ions, trace elements (As, B, Ba, Ca, Fe, K, Li, Mg, Mn, Mo, Pb, Si, Sr, Zn), and stable isotopes in water (δ18 …


Interpreting Southern California Arc Geochemistry By Multivariate And Spatial Methods, Lance R. Pompe Sep 2016

Interpreting Southern California Arc Geochemistry By Multivariate And Spatial Methods, Lance R. Pompe

Loma Linda University Electronic Theses, Dissertations & Projects

Exploratory data analysis methods of multivariate statistical techniques and spatial visualization are emerging trends in understanding big datasets. In this project, these techniques are applied to a large igneous geochemical dataset from the southern California segment of the Mesozoic Cordilleran arc to better understand magmatic and plate tectonic processes at a subduction zone. A set of 287 granitic samples collected by Baird and Miesch (1984) from the Peninsular Ranges batholith is analyzed for 38 geochemical elements. Patterns in both the geochemical variation and the spatial variation of this dataset are explored. Since geochemical data are compositional in nature, special treatment …


Depositional Model Of A Late Cretaceous Dinosaur Fossil Concentration, Lance Formation, Summer Rose Weeks Sep 2016

Depositional Model Of A Late Cretaceous Dinosaur Fossil Concentration, Lance Formation, Summer Rose Weeks

Loma Linda University Electronic Theses, Dissertations & Projects

A large Maastrichtian, nearly monospecific bonebed in the Lance Formation in eastern Wyoming has yielded 13,000 bones and fragments since 1996. Though excavation of the site continues, little is known of the circumstances and processes of deposition. This study aims to provide a depositional model for the bonebed. To accomplish this task we utilized 1D facies analysis of surrounding units and 3D analysis of the bonebed. The nature of the outcrop limited facies analysis to 1D. Four measured stratigraphic sections, each containing the bonebed unit, were taken and used in facies analysis. In addition, laterally continuous units were observed and …


Relationships Between Surface And Ground Water Velocities Determined From Dye Trace Experiments In Mcconnell Springs And Preston's Cave Spring, Lexington, Fayette County, Kentucky, Laura A. Norris, Cassie E. Simpson, Trent Garrison Aug 2016

Relationships Between Surface And Ground Water Velocities Determined From Dye Trace Experiments In Mcconnell Springs And Preston's Cave Spring, Lexington, Fayette County, Kentucky, Laura A. Norris, Cassie E. Simpson, Trent Garrison

EKU Faculty and Staff Scholarship

In mature karst regions, water may flow through large subsurface conduits, expediting flow to surficial karst springs. In the fall of 2015, a dye trace was performed in the Middle Ordovician karst of Lexington, Fayette County, Kentucky in order to measure ground water velocities. Other aspects of the study include (1) comparing these velocities to surface water velocities at discharge points (springs) and (2) comparing karst conduit velocities to granular velocities from previous studies in the region. The locations selected for study include (1) the “Campbell House Sinkhole," (2) McConnell Springs, and (3) Preston’s Cave Spring.


The Bear River's History And Diversion: Constraints, Unsolved Problems, And Implications For The Lake Bonneville Record, Joel L. Pederson, Susanne U. Jänecke, M. C. Reheis, D. S. Kaufman, Robert Q. Oaks Jr. Aug 2016

The Bear River's History And Diversion: Constraints, Unsolved Problems, And Implications For The Lake Bonneville Record, Joel L. Pederson, Susanne U. Jänecke, M. C. Reheis, D. S. Kaufman, Robert Q. Oaks Jr.

Geosciences Faculty Publications

The shifting course of the Bear River has influenced the hydrologic balance of the Bonneville basin through time, including the magnitude of Lake Bonneville. This was first recognized by G.K. Gilbert and addressed in the early work of Robert Bright, who focused on the southeastern Idaho region of Gem Valley and Oneida Narrows. In this chapter, we summarize and evaluate existing knowledge from this region, present updated and new chronostratigraphic evidence for the Bear River's drainage history, and discuss implications for the Bonneville record as well as future research needs.

The Bear River in Plio-Pleistocene time joined the Snake River …


Calcium Carbonate Formation In Energy-Related Subsurface Environments And Engineered Systems, Qingyun Li Aug 2016

Calcium Carbonate Formation In Energy-Related Subsurface Environments And Engineered Systems, Qingyun Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Geologic CO2 sequestration (GCS) in subsurface saline aquifers is a promising strategy to mitigate climate change caused by increasing anthropogenic CO2 emissions from energy production. At GCS sites, interactions between fluids and geomedia are important because they can affect CO2 trapping efficiency and the safety of CO2 storage. These interactions include the dissolution and precipitation of minerals. One of the most important minerals is calcium carbonate, because it can permanently trap CO2.

In this work, Portland cement was used as a model geomedium to investigate the chemical reactions, mechanical alterations, transport of reactive fluids, and the interplay of all these …


Silicic Volcanism At The Northern And Western Extent Of The Columbia River Basalt Rhyolite Flare-Up: Rhyolites Of Buchanan Volcanic Complex And Dooley Mountain Volcanic Complex, Oregon, Adam M. Large Aug 2016

Silicic Volcanism At The Northern And Western Extent Of The Columbia River Basalt Rhyolite Flare-Up: Rhyolites Of Buchanan Volcanic Complex And Dooley Mountain Volcanic Complex, Oregon, Adam M. Large

Dissertations and Theses

Two mid-Miocene (16.5-15 Ma) rhyolite volcanic centers in eastern Oregon, the Buchanan rhyolite complex and Dooley Mountain rhyolite complex, were investigated to characterize eruptive units through field and laboratory analysis. Results of petrographic and geochemical analysis add to field observations to differentiate and discriminate the eruptive units. Additionally, new geochemical data are used to correlate stratigraphically younger and older basalt and ash-flow tuff units with regional eruptive units to constrain the eruptive periods with modern Ar-Ar age dates.

Previous work at the Buchanan rhyolite complex was limited to regional mapping (Piper et al., 1939; Greene et al., 1972) and brief …


Tube Coalescence In The Jingfudong Lava Tube And Implications For Lava Flow Hazard Of Tengchong Volcanism, Zhengquan Chen, Yongshun Liu, Haiquan Wei, Jiandong Xu, Wenfeng Guo Aug 2016

Tube Coalescence In The Jingfudong Lava Tube And Implications For Lava Flow Hazard Of Tengchong Volcanism, Zhengquan Chen, Yongshun Liu, Haiquan Wei, Jiandong Xu, Wenfeng Guo

International Journal of Speleology

Tube-fed structure occurs as a general phenomenon in Tengchong basic lavas, such as lava tubes, lava plugs and tube-related collapse depressions. We deduced the development of Laoguipo lava flows, which is the longest lava tube (Jingfudong lava tube) evolved in Tengchong volcanic area. Following the detailed documentation of the tube morphology of the Jingfudong lava tube, we propose that the Jingfudong lava tube was formed through vertical coalescence of at least three tubes. The coalescence and bifurcation process are re-constructed by interpretation of tube floor continuity, the distribution of remnant tubes and the scales of lava tube branches (shapes of …


Bulletin No. 42: The Mamacoke Conservation Area, Glenn Dreyer, Robert Askins, Scott Peterson Aug 2016

Bulletin No. 42: The Mamacoke Conservation Area, Glenn Dreyer, Robert Askins, Scott Peterson

Bulletins

No abstract provided.


Development And Curation Of The Sample Data Library For The Astrobiogeochemistry Laboratory, Meika R. Nwaomah, Lorenia Jimenez, Michael Tuite Aug 2016

Development And Curation Of The Sample Data Library For The Astrobiogeochemistry Laboratory, Meika R. Nwaomah, Lorenia Jimenez, Michael Tuite

STAR Program Research Presentations

In 2011, the National Science Foundation (NSF) initiated EarthCube, an integrated cyber infrastructure initiative, to tackle challenges within geoscience research. EarthCube’s goal is to improve public access and collaboration within the geoscience community. During the summer of 2015, the Astrobiogeochemistry Laboratory (abcLab) joined the collective efforts of EarthCube by developing the Sample Data Library (SDL) for the Jet Propulsion Laboratory (JPL). The main focus of the SDL concentrates on effectively curating the samples collected by researchers within the Planetary Chemistry and Astrobiology section at JPL. The goal of this summer internship was to assimilate field notes, images, and from data …


Fort Nelson Ccs Feasibility Project, University Of North Dakota. Energy And Environmental Research Center Aug 2016

Fort Nelson Ccs Feasibility Project, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about a 2009–2012 Plains CO2 Reduction (PCOR) Partnership collaboration with Spectra Energy Transmission (Spectra) to determine the feasibility of a commercial-scale geology storage project near the Fort Nelson Gas Plant. Describes the project, its goals, and key results. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Stratigraphy Of The Upper Devonian-Lower Mississippian Michigan Basin: Review And Revision With An Emphasis On The Ellsworth Petroleum System, Bryan J. Currie Aug 2016

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 …


The Role Of The Picuris Orogeny In The Tectonic Evolution Of Proterozoic North America, Ruth Frances Aronoff Aug 2016

The Role Of The Picuris Orogeny In The Tectonic Evolution Of Proterozoic North America, Ruth Frances Aronoff

Open Access Dissertations

North America is a continent that has grown over time by horizontal attachment of material onto its margins. Studying the process of continental growth in the geologic past gives insight into fundamental components of plate tectonics, and sheds light onto processes at work at modern plate boundaries, in which mid- and lower-crustal rocks are generally hidden from view.

This study focuses on the growth of North America during the Proterozoic. Researchers have debated the role of three orogenies in shaping the southwestern margin of North America: the ∼1.80-1.60 Ga Yavapai and Mazatzal orogenies, and the newly recognized ∼1.40 Ga Picuris …


Topographic Constraints On Magma Accumulations Below The Actively Uuplifting Uturuncu And Lazufre Volcanic Centers In The Central Andes, Jonathan P. Perkins, Noah J. Finnegan, Scott T. Henderson, Tammy M. Rittenour Aug 2016

Topographic Constraints On Magma Accumulations Below The Actively Uuplifting Uturuncu And Lazufre Volcanic Centers In The Central Andes, Jonathan P. Perkins, Noah J. Finnegan, Scott T. Henderson, Tammy M. Rittenour

Geosciences Faculty Publications

Geodetic surveys of Volcán Uturuncu and the Lazufre volcanic complex in the Central Andes of South America reveal sustained surface uplift from magmatic intrusion at depth. However, the decadal timescales of geodetic surveys are short relative to the timescales of magma chamber growth. Thus, from geodesy alone, it is difficult to infer the deformation and hence magma accumulation history of these volcanoes. Here we combine data from InSAR, long-wavelength topography, GPS and high-resolution topographic surveys of lake shorelines and rivers, and lava flow morphology to constrain the spatial and temporal evolution of magmatism at Uturuncu and Lazufre. Near Uturuncu, dated …


Do Limestone Quarries Act As “Engineered Sinkholes”? Analysis Of Exfiltration Of Groundwater From Limestone Quarries In The Boone Formation, Ozark Physiographic Province, Arkansas, Usa, Noel Turner Aug 2016

Do Limestone Quarries Act As “Engineered Sinkholes”? Analysis Of Exfiltration Of Groundwater From Limestone Quarries In The Boone Formation, Ozark Physiographic Province, Arkansas, Usa, Noel Turner

Graduate Theses and Dissertations

Limestone quarries are a source of construction materials that are utilized in our everyday lives. Karst landscapes cover up to 15 percent of the Earth’s surface, and limestone quarries are found in these environmentally sensitive regions where groundwater and surface-water interactions are dynamic and complex. Several studies have provided conceptual models of groundwater flow to and out of quarries. The goal of this research was to describe the geochemistry of water exfiltration from limestone quarries in karst regions via joints, fractures, faulting, or karst features and to determine if limestone quarries are “engineered sinkholes”; that is to say: did quarries, …


Geologic, Geochemical, And Geophysical Characterization Of The Gold Deposits Of The Horseshoe Bend Mining District, Idaho: Building A Four Dimensional Model For Ore Exploration, Joshua Ekhoff Aug 2016

Geologic, Geochemical, And Geophysical Characterization Of The Gold Deposits Of The Horseshoe Bend Mining District, Idaho: Building A Four Dimensional Model For Ore Exploration, Joshua Ekhoff

Boise State University Theses and Dissertations

The Eocene aged Trans-Challis Fault System of central Idaho provides the tectonic and magmatic framework for a series of Au-Ag and Cu-Mo ore deposits. From its northernmost extension near Butte, Montana to its southwestern terminus in the Boise Basin of south-central Idaho the Trans-Challis Fault System is associated with some of the richest precious metal deposits found in Idaho. However, the southernmost tip of the Trans-Challis Fault System, composed of the Horseshoe Bend and Pearl mining districts, remains understudied, receiving little economic or academic attention. As a result, how the Pearl to Horseshoe Bend mining districts fit within the established …


Protracted Thrusting Followed By Late Rapid Cooling Of The Greater Himalayan Sequence, Annapurna Himalaya, Central Nepal: Insights From Titanite Petrochronology, Jesse Bennett Walters Aug 2016

Protracted Thrusting Followed By Late Rapid Cooling Of The Greater Himalayan Sequence, Annapurna Himalaya, Central Nepal: Insights From Titanite Petrochronology, Jesse Bennett Walters

Boise State University Theses and Dissertations

Temperature-time (T-t) paths derived from coupled Zr-in-titanite thermometry and U-Pb geochronology are useful for examining middle-crustal tectonic processes. T-t data collected from the titanite-bearing calcsilicates of the upper Greater Himalayan Sequence (GHS) along the Marsyandi River, Annapurna Himalaya, illustrate a significantly different metamorphic history than previously recorded in central Nepal. Combined with traditional thermobarometry, textural relationships, and field mapping, titanite T-t data reveal a protracted history of mid-crustal tectonics. Peak Zr-in-titanite temperatures are 750-850 °C at 10-14 kbar. T-t paths are divided into two groups, which are separated by the Chame Shear Zone (CSZ). Group I (upper) rocks show cooling …


Groundwater-Surface Water Interactions Near Mosier, Oregon, Cullen Brandon Jones Aug 2016

Groundwater-Surface Water Interactions Near Mosier, Oregon, Cullen Brandon Jones

Dissertations and Theses

The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that …


Patterns Of Synorogenic Sedimentation Associated With The Unroofing Of The Willard-Paris-Meade Thrust Sheets, Sevier Fold-Thrust Belt, Amanda Gentry Aug 2016

Patterns Of Synorogenic Sedimentation Associated With The Unroofing Of The Willard-Paris-Meade Thrust Sheets, Sevier Fold-Thrust Belt, Amanda Gentry

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Willard-Paris-Meade thrust is the oldest and western-most sheet to develop in the Wyoming salient of the Sevier fold-thrust belt. The 10-15 km thick thrust sheet was emplaced ~60 km eastward and included Jurassic-Triassic strata, mixed siliciclastic-carbonate upper Paleozoic strata, carbonate-rich lower Paleozoic strata, and quartzite-rich basal Cambrian to Neoproterozoic strata. Each stratigraphic interval has a distinctive detrital zircon (DZ) age signature, which can be used in provenance analysis of foreland basin fill. The thrust system had a long deformation history recorded by westward thickening and coarsening synorogenic strata. DZ U-Pb geochronology of 27 synorogenic samples collected from two transects …


Structural Evolution Of The Maynard Lake Fault Within The Left-Lateral Pahranagat Shear Zone, Nevada, Usa, Mahmud Mustafa Muhammad Aug 2016

Structural Evolution Of The Maynard Lake Fault Within The Left-Lateral Pahranagat Shear Zone, Nevada, Usa, Mahmud Mustafa Muhammad

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Pahranagat shear zone (PSZ) contains three ENE-striking left-lateral strike-slip faults: The Arrowhead Mine fault (AMF), Buckhorn fault (BF), and Maynard Lake fault (MLF) from north to south. This shear zone lies along the boundary between the northern and central Basin and Range physiographic sub-provinces (NBR-CBR). In addition, this zone is positioned SW of a regional strike-slip zone, the Caliente-Enterprise zone (CEZ), and surrounded by extensional domains with differences in timing and magnitude of extension. Hence, understanding the development of the PSZ, particularly the MLF, is essential to better understanding tectonic evolution of the boundary zone between the northern and …