Tectonics and Structure Commons^™

Groundwater Level Response To The Wenchuan Earthquake Of May 2008, Anhua He, Ramesh Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

We have comprehensively analysed the co-seismic response of the groundwater levels of 280 wells in mainland China that were associated with the Wenchuan earthquake (Mw 7.9) that occurred on 12 May 2008. The observed co-seismic responses can be classified as step-like changes in 138 wells, variations in 69 wells and non-responses in 73 wells. After a quantitative analysis of spatial distribution, there was no spatially coherent signal found in the step-like changes (positive values indicate a step-like rise, and negative values indicate a step-like fall), even within 300 km of the epicenter. The amplitude and the phase shift of the …

Land Use And Land Cover Changes, And Environment And Risk Evaluation Of Dujiangyan City (Sw China) Using Remote Sensing And Gis Techniques, Biswajit Nath, Zheng Niu, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

Understanding of the Land Use and Land Cover (LULC) change, its transitions and Landscape risk (LR) evaluation in earthquake-affected areas is important for planning and urban sustainability. In the present study, we have considered Dujiangyan City and its Environs (DCEN), a seismic-prone area close to the 2008 Wenchuan earthquake (8.0 Mw) during 2007–2018. Five different multi-temporal data sets for the years 2007, 2008, 2010, 2015, and 2018 were considered for LULC mapping, followed by the maximum likelihood supervised classification technique. The individual LULC maps were further used in four time periods, i.e., 2007–2018, 2008–2018, 2010–2018, and 2015–2018, to evaluate the …

Crustal Seismic Anisotropy Of The Ruby Mountains Core Complex And Surrounding Northern Basin And Range, Justin T. Wilgus

Earth and Planetary Sciences ETDs

Metamorphic core complexes (MCC) are distinctive uplifts that expose deeply exhumed and deformed crustal rocks due to localized extensional deformation. Consequently, their detailed structure provide a window into deep crustal mechanics. The North American Cordillera contains numerous MCC, one of which is the Ruby Mountains core complex (RMCC) located in the highly extended northern Basin and Range. To constrain the extent to which anisotropy below the RMCC deviates from the regional Basin and Range average and test the depth dependence of crustal anisotropy we conduct a radial anisotropy investigation below the RMCC and surrounding northern Basin and Range. Data from …

The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis, And Age, Jan Lenart, Martin Kašing, Petr Tábořík, Natalia Piotrowska, Jacek Pawlyta

International Journal of Speleology

The Cyrilka Cave is the second longest pseudokarst cave and the longest crevice-type cave in Czechia. Developed within the headscarp area of a deep-seated landslide, the cave became a focus of scientific research in recent years when new passages were discovered. Structural analysis provided a general tectonic plan of the cave, as well as more detailed data on geometry and kinematics of the relaxed rock massif. The primary structure of NNE- to ENE-striking bedding is broken by a system of NNE-striking fissures interconnected by two continuous ENE-striking dextral fracture zones. Abundant signs of recent sinistral strike-slips within the rock massif …

New Borehole Breakout Derived Stress Constraints And Their Implications For Stress Heterogeneity Near High Risk Fault Systems In The Santa Barbara Channel, Southern California, Edward Harris Pritchard

LSU Master's Theses

The Santa Barbara Channel represents the offshore portion of the Ventura Basin in Southern California. Ongoing transpression related to a regional left step in the San Andreas Fault has led to the formation of E-W trending en-echelon fault systems, with both north and south dips, which accommodate varying rates of localized shortening across the basin. Recent studies have suggested that faults within the northern region of the channel could be capable of a multisegment rupture and producing a M_w 7.7–8.1 tsunamigenic earthquake. However, dynamic rupture models producing these results have not accounted for stress heterogeneity, which is …

Unroofing History Of The Northwestern Ethiopian Plateau: Insights From Low-Temperature Apatite Thermochronology, Shelby Bowden

Masters Theses & Specialist Projects

The geology of Ethiopia is dominated by the Ethiopian Plateau that is similar in elevation to, but aerially larger than, the Colorado Plateau. Several rivers have incised through the plateau, creating gorges that reach up to 1.5 km in depth. The plateau uplifted to its current elevation and was subsequently incised sometime after the Oligocene flood basalt event that signaled the arrival of the African Superplume below Kenya and Ethiopia. Due to its size and extent, published climate modeling has indicated that Late Cenozoic plateau formation could have been a driving force in the East African Cenozoic climate changes. Although …

Structural Evolution And Petroleum Potential Of A Cambrian Intracratonic Rift System: Mississippi Valley Graben, Rough Creek Graben, And Rome Trough, John B. Hickman, David C. Harris

Report of Investigations--KGS

Drilling and geophysical data demonstrate that the Mississippi Valley Graben, Rough Creek Graben, and Rome Trough are fault-bounded structures filled with as much as 27,000 ft of Cambrian sediments. Data including stratigraphic tops from 1,764 wells, 106 seismic profiles, aeromagnetic and gravity surveys, and mapped surface geology at a scale of 1:24,000 were used to study seven stratigraphic packages across parts of Kentucky, Ohio, Indiana, Illinois, Missouri, and Tennessee. Detailed analysis of the thickness patterns of these stratigraphic packages was used to interpret the locations and timing of movement along major fault systems in the study area.

Active rifting of …

On The Interaction Of The North Andes Plate With The Caribbean And South American Plates In Northwestern South America From Gps Geodesy And Seismic Data, Omar J. Pérez, Steven G. Wesnousky, Roberto De La Rosa, Julio Márquez, Redescal Uzcátegui, Christian Quintero, Luis Liberal, Héctor Mora-Páez, Walter Szeliga

All Faculty Scholarship for the College of the Sciences

We examine the hypocentral distribution of seismicity and a series of geodetic velocity vectors obtained from Global Positioning System observations between 1994 and 2015 both offshore and mainland northwestern South America (66°W–77°W; 8°N–14°N). Our analysis, that includes a kinematic block modelling, shows that east of the Caribbean–South American–North Andes plates’ triple junction at ∼68°W; 10.7°N, right-lateral easterly oriented shear motion (∼19.6 ± 2.0 mm yr⁻¹) between the Caribbean and South America plates is split along two easterly striking, right-lateral strike-slip subparallel fault zones: the San Sebastián fault that runs off-shore the Venezuelan coast and slips about 17.0±0.5mm …

Stylolites Cathodoluminescence Under Cross Polarized Light, Katherine Dvorak

The Hilltop Review

Devil's Gate limestone under cathodoluminescence. Bright yellow and orange areas are calcite and the bright blue indicates trace minerals along the solution seam. Trace minerals left in the seam are heavy metals and other silicate minerals.

The Transition From Sevier To Laramide Orogeny Captured In Upper-Plate Magmatic Structures, Eastern Transverse Ranges, Ca, Brody Friesenhahn

Earth Sciences Theses and Dissertations

The onset of the Laramide orogeny is of great tectonic significance to the geologic history of the US, but the timing and nature of the shift between Sevier and Laramide tectonics remains enigmatic. The eastern Transverse Ranges of southern California provide the opportunity to observe the effects of Laramide tectonics on the mid-crust. Wide Canyon is a north/south-trending canyon in the northern Little San Bernardino Mountains of the eastern Transverse Ranges. Al-in-hornblende thermobarometry of Needy et al. (2009) yields a projected paleodepth depth of ~20 km for Wide Canyon where Cretaceous granitoids intrude metamorphic country rock of Proterozoic age in …

Review Of Curbing Catastrophe: Natural Hazards And Risk Reduction In The Modern World, Kira H. Hamman

Numeracy

Timothy H. Dixon. 2017. Curbing Catastrophe: Natural Hazards and Risk Reduction in the Modern World. (New York, NY: Cambridge University Press) 300 pp. ISBN 978-1108113663.

In Curbing Catastrophe, Timothy H. Dixon explores commonalities among natural disasters like Hurricane Katrina, the 2010 earthquake in Haiti, and the meltdown at Fukushima. He identifies communication failure between scientists and policy makers as a major culprit in the devastation that results from such events and offers strategies for improving that communication. He includes optional in-depth scientific and quantitative examinations of the events and the resulting devastation, making the book appropriate for use …

Integrated Geophysical Analysis In The Northeastern Gulf Of Mexico, Mei Liu

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The formation of the Gulf of Mexico (GoM) relates to the breakup of Pangea and opening of the central Atlantic Ocean. The tectonic history of the basin is still being debated due to lack of geological constraints. This project addresses the crustal architecture in the northeastern GoM from integrative analysis of multiple geophysical datasets to provide constraints for the tectonic reconstruction.

The objectives of this study are: 1) to delineate various tectonic zones (continental and oceanic domains) and map the boundary between them, 2) to derive physical properties of the subsurface rocks, 3) to map the major tectonic structures in …

Large Rotations Of Crustal Blocks In The Tjörnes Fracture Zone Of Northern Iceland, Andrew J. Horst, J. A. Carson, R. J. Varga

Natural Resources and Earth Sciences Faculty Research

The interpretation of uppermost crustal deformation near oceanic transform faults is based on bathymetric lineaments and earthquake focal mechanisms, and relatively little is known about the detailed kinematics within the transform tectonized zone. The Tjörnes Fracture Zone is a broad zone of deformation produced by right‐lateral transform shearing in north Iceland and is partly exposed on land providing the opportunity to study shallow‐level crustal structure of mid‐Miocene, thick, oceanic‐like crust formed by subaerial spreading. A pronounced structural curvature of lava and dike orientations near the Húsavík‐Flatey Fault within the transform zone is well documented, yet of controversial origin. In order …

Miocene-Quaternary Deformation Along The Central Maynard Lake Fault, Pahranagat Shear Zone, Nevada, Alexander Peck

UNLV Theses, Dissertations, Professional Papers, and Capstones

The left-lateral Pahranagat shear zone (PSZ) and Caliente-Enterprise zone (CEZ) exist at the boundary between two sub-provinces, the Northern (NBR) and Central Basin and Range (CBR). The PSZ contains three major ENE striking sinistral faults, including the Maynard Lake fault (MLF), which is the longest fault and marks the southern boundary of the zone. The PSZ has been suggested to be a transfer zone, but little is known about the structures along these major faults that are involved in strain transfer. These left-lateral systems exist within the Central Nevada seismic belt which has experienced significant earthquakes in recent history. Possible …

Structural Geology Of The Caddo Gap Area, Ouachita Mountains, Arkansas, Martin Messmer

Electronic Theses and Dissertations

The Caddo Gap quadrangle is located on the southern margin of the Benton Uplift, the orogenic core of the Ouachita Mountains. Recent field mapping focused on delineating stratigraphic and structural relationships in the southern part of the quadrangle to improve existing reconnaissance-scale maps of the area. New structures were discovered that provide further information about the structural evolution of the Ouachita fold and thrust belt.

Field work included mapping the three informal members (Lower, Middle and Upper) of the Arkansas Novaculite. Major folds within the study area include the Nelson Mountain Anticline and two synclinal folds (“South Caddo Mountain” and …

Evolution And Controls Of Large Glacial Lakes In The Nepal Himalaya, Umesh K. Haritashya, Jeffrey S. Kargel, Dan H. Shugar, Gregory J. Leonard, Katherine Strattman, C. Scott Watson, David Shean, Stephan Harrison, Kyle T. Mandli, Dhananjay Regmi

Department of Earth, Environment and Sustainability Faculty Publications

Glacier recession driven by climate change produces glacial lakes, some of which are hazardous. Our study assesses the evolution of three of the most hazardous moraine-dammed proglacial lakes in the Nepal Himalaya—Imja, Lower Barun, and Thulagi. Imja Lake (up to 150 m deep; 78.4 x 10⁶ m³ volume; surveyed in October 2014) and Lower Barun Lake (205 m maximum observed depth; 112.3 x 10⁶ m³ volume; surveyed in October 2015) are much deeper than previously measured, and their readily drainable volumes are slowly growing. Their surface areas have been increasing at an accelerating pace from a …

Supplemental Data For 'Evolution And Controls Of Large Glacial Lakes In The Nepal Himalaya', Umesh K. Haritashya, Jeffrey S. Kargel, Dan H. Shugar, Gregory J. Leonard, Katherine Strattman, C. Scott Watson, David Shean, Stephan Harrison, Kyle T. Mandli, Dhananjay Regmi

Department of Earth, Environment and Sustainability Faculty Publications

Supplementary data for the article "Evolution and Controls of Large Glacial Lakes in the Nepal Himalaya"

Structural Synthesis And Spatial Distribution Of A 335 Ma Igneous Suite From The Eastern Blue Ridge, Alabama Appalachians, Avery Rosenbalm

Honors Theses

The Appalachian range was formed by three orogenies, the most recent being the Alleghanian beginning at ~330 Ma. A small pluton outcropping along Highway 280 near Alexander City, AL, called the 280 granodiorite, has been dated at ~335 Ma and intrudes the Devonian Elkahatchee Quartz Diorite (EQD). While little work has been done on the intrusion, it is significant because of its age: all deformation of the intrusion should be related to the Alleghanian orogeny, while most other bodies in the region exhibit significant overprinting due to previous successive orogenies. The pluton was mapped constraining the geographic extent, which is …

Geology Of The Purgatory Saddle 7.5 Minute Quadrangle, And Gravity And Magnetic Analysis Of Accreted Terrane Boundary, Western Idaho, Sourav Krishna Nandi

Graduate Theses/Dissertations

Western Idaho (USA) contains deformation associated with the Mesozoic accretion of volcanic island arc terranes of the Blue Mountains Province to Laurentia. The near vertical boundary between the accretionary orogeny and Precambrian North America is represented by the transpressional western Idaho shear zone, which lies east of metamorphic rocks in the Salmon River suture zone. The Blue Mountains Province in western Idaho contains four accreted crustal blocks: the Wallowa, Olds Ferry, Baker, and Izee terranes. The purpose of this study is to understand the structural relationship of the pre-accretionary, syn-accretionary and post-accretionary tectonic features along the accreted terrane boundary in …

Structural Cross Sections And Subsurface Maps Of The Atoka Formation In The Northern Arkoma Basin, Western And Northwestern Arkansas, David Nance

Graduate Theses and Dissertations

The Arkoma Basin is one of several peripheral foreland basins situated on the front of the Ouachita orogenic fold and thrust belt. The transition from the foredeep to the Ozark Plateaus is a short one in terms of latitude. The Atoka Formation in Arkansas comprises the bulk of the sediments in the Arkoma Basin. Three divisions of the Atoka Formation have been informally assigned as the Upper, Middle, and Lower based on differences in sedimentary response to tectonic processes that occurred during the formation and subsidence of the Arkoma Basin. In the Arkansas portion of the Arkoma Basin, the lower …

Regional Stress Regime Study Of East Texas Based On Orientation Of Fractures In The Weches Formation, Cory D. Ellison

Electronic Theses and Dissertations

Fractures in the Weches Formation in a roughly 50 mile radius around Nacogdoches, Texas were documented and analyzed using data obtained at various outcrops. This data was used to infer information about the regional stress regime based on the direction of maximum/minimum horizontal stresses (SHmax / SHmin) that formed the fractures. This is based on the principle that systematic, steeply dipping, mode I joints propagate in the direction of SHmax and normal to the direction of SHmin. Joints in the Weches Formation are typically iron filled and are predominantly opening mode, indicated by crack-seal formation, steep dip (700 – 900) …

Climate Change And The Global Pattern Of Moraine-Dammed Glacial Lake Outburst Floods, Stephan Harrison, Jeffrey S. Kargel, Christian Huggel, John Reynolds, Dan H. Shugar, Richard A. Betts, Neil Glasser, Umesh K. Haritashya, Jan Klimeš, Liam Reinhardt, Yvonne Schaub, Andy Wiltshire, Dhananjay Regmi, Vít Vilímek

Department of Earth, Environment and Sustainability Faculty Publications

Despite recent research identifying a clear anthropogenic impact on glacier recession, the effect of recent climate change on glacier-related hazards is at present unclear. Here we present the first global spatio-temporal assessment of glacial lake outburst floods (GLOFs) focusing explicitly on lake drainage following moraine dam failure. These floods occur as mountain glaciers recede and downwaste. GLOFs can have an enormous impact on downstream communities and infrastructure. Our assessment of GLOFs associated with the rapid drainage of moraine-dammed lakes provides insights into the historical trends of GLOFs and their distributions under current and future global climate change. We observe a …

Spatially Heterogeneous Post-Caledonian Burial And Exhumation Across The Scottish Highlands, Michelle L. Fame, James A. Spotila, Lewis A. Owen, Jason M. Dortch, David L. Shuster

Faculty, Staff, and Affiliated Publications--KGS

The postassembly, postrift evolution of passive margins is an essential element of global continental tectonics. Thermal and exhumational histories of passive margins are commonly attributed to a number of drivers, including uplift and erosional retreat of a rift-flank escarpment, intraplate fault reactivation, mantle-driven uplift, and erosional disequilibrium, yet in many cases, a specific factor may appear to dominate the history of a given passive margin. Here, we investigate the complex evolution of passive margins by quantifying exhumation patterns in western Scotland. We build upon the well-studied thermal evolution of the Scottish North Atlantic passive margin to test the importance of …

Gps Vertical Land Motion Corrections To Sea-Level Rise Estimates In The Pacific Northwest, Jean-Philippe Montillet, Timothy I. Melbourne, Walter M. Szeliga

All Faculty Scholarship for the College of the Sciences

We construct coastal Pacific Northwest profiles of vertical land motion (VLM) known to bias long-term tide-gauge measurements of sea-level rise (SLR) and use them to estimate absolute sea-level rise with respect to Earth’s center of mass. Multidecade GPS measurements at 47 coastal stations along the Cascadia subduction zone show VLM varies regionally but smoothly along the Pacific coast and inland Puget Sound with rates ranging from +4.9 to –1.2 mm/yr. Puget Sound VLM is characterized by uniform subsidence at relatively slow rates of +0.1 to –0.3 mm/yr. Uplift rates of 4.5 mm/yr persist along the western Olympic Peninsula of northwestern …

An Overview Of Anorthosite-Bearing Layered Intrusions In The Archaean Craton Of Southern West Greenland And The Superior Province Of Canada: Implications For Archaean Tectonics And The Origin Of Megacrystic Plagioclase, Ali Polat, Fred J. Longstaffe, Robert Frei

Earth Sciences Publications

Anorthosite-bearing layered intrusions are unique to the Archaean rock record and are abundant in the Archaean craton of southern West Greenland and the Superior Province of Canada. These layered intrusions consist mainly of ultramafic rocks, gabbros, leucogabbros and anorthosites, and typically contain high-Ca (>An₇₀) megacrystic (2–30 cm in diameter) plagioclase in anorthosite and leucogabbro units. They are spatially and temporally associated with basalt-dominated greenstone belts and are intruded by syn-to post-tectonic granitoid rocks. The layered intrusions, greenstone belts and granitoids all share the geochemical characteristics of Phanerozoic subduction zone magmas, suggesting that they formed mainly in a …

Petrogenetic And Geodynamic Origin Of The Neoarchean Doré Lake Complex, Abitibi Subprovince, Superior Province, Canada, Ali Polat, Robert Frei, Fred J. Longstaffe, Ryan Woods

Earth Sciences Publications

The Neoarchean (ca. 2728 Ma) anorthosite-bearing Doré Lake Complex in the northeastern Abitibi subprovince, Quebec, was emplaced into an association of intra-oceanic tholeiitic basalts and gabbros known as the Obatogamau Formation. The Obatogamau Formation constitutes the lower part of the Roy Group, which is composed of two cycles of tholeiitic-to-calc-alkaline volcanic and volcaniclastic rocks, siliciclastic and chemical sedimentary rocks, and layered mafic-to-ultramafic sills. In this study, we report major and trace element results, and Nd, Sr, Pb and O isotope data for anorthosites, leucogabbros, gabbros and mafic dykes from the Doré Lake Complex and spatially associated basalts and gabbros of …

Petrology And Geochemistry Of The Tasse Mantle Xenoliths Of The Canadian Cordillera: A Record Of Archean To Quaternary Mantle Growth, Metasomatism, Removal, And Melting, Ali Polat, Robert Frei, Fred J. Longstaffe, Derek J. Thorkelson, Eyal Friedman

Earth Sciences Publications

Mantle xenoliths hosted by the Quaternary Tasse alkaline basalts in the Canadian Cordillera, southeastern British Columbia, are mostly spinel lherzolite originating from subcontinental lithospheric mantle. The xenoliths contain abundant feldspar veins, melt pockets and spongy clinopyroxene, recording extensive alkaline metasomatism and partial melting. Feldspar occurs as veins and interstitial crystal in melt pockets. Melt pockets occur mainly at triple junctions, along grain boundaries, and consist mainly of olivine, cpx, opx and spinel surrounded by interstitial feldspar. The Nd, Sr and Pb isotopic compositions of the xenoliths indicate that their sources are characterized by variable mixtures of depleted MORB mantle and …

Conservation Limnogeology And Benthic Habitat Mapping In Central Lake Tanganyika (Tanzania), Joseph S. Lucas

Theses and Dissertations--Earth and Environmental Sciences

Small scale protected zones are valuable for helping the health and productivity of fisheries at Lake Tanganyika (East Africa). Spatial placement of protected areas relies on accurate maps of benthic habitats, consisting of detailed bathymetry data and information on lake-floor substrates. This information is unknown for most of Lake Tanganyika. Fish diversity is known to correlate with rocky substrates in ≤ 30 m water depth, which provide spawning grounds for littoral and pelagic species. These benthic habitats form important targets for protected areas, if they can be precisely located.

At the NMVA, echosounding defined the position of the 30-m isobath …

Spatial And Temporal Characterization Of The Petrified Springs Fault, Central Walker Lane, Nevada: Documenting Middle Miocene Dextral Slip, Andrew Hoxey

All Master's Theses

The Central Walker Lane, NV is an active dextral shear zone superimposed on the western boundary of the Basin and Range extensional province. Approximately 25% of dextral shear along the Pacific-North American plate boundary accommodated in the Walker Lane, a NW-striking, intracontinental dextral fault system in eastern California- western Nevada. In the Central Walker Lane, shear is accommodated on five major NW- striking faults, one of which is the Petrified Springs fault, with poorly constrained slip magnitudes, slip rates, and initiation ages. We completed new detailed geologic mapping, combined with structural studies, and ⁴⁰Ar/³⁹Ar geochronology document offset …