Geology Commons^™

Deep Structure Of Siletzia In The Puget Lowland: Imaging An Obducted Plateau And Accretionary Thrust Belt With Potential Fields, Megan L. Anderson, Richard J. Blakely, Ray E. Wells, Joe D. Dragovich

Geology Faculty Publications and Presentations

Detailed understanding of crustal components and tectonic history of forearcs is important due to their geological complexity and high seismic hazard. The principal component of the Cascadia forearc is Siletzia, a composite basaltic terrane of oceanic origin. Much is known about the lithology and age of the province. However, glacial sediments blanketing the Puget Lowland obscure its lateral extent and internal structure, hindering our ability to fully understand its tectonic history and its influence on modern deformation. In this study, we apply map-view interpretation and two-dimensional modeling of aeromagnetic and gravity data to the magnetically stratified Siletzia terrane revealing its …

2023’S Billion-Dollar Disasters List Shattered The Us Record With 28 Big Weather And Climate Disasters Amid Earth’S Hottest Year On Record, Shuang-Ye Wu

Geology Faculty Publications

The U.S. set an unwelcome record for weather and climate disasters in 2023, with 28 disasters that exceeded more than US$1 billion in damage each.

While it wasn’t the most expensive year overall – the costliest years included multiple hurricane strikes – it had the highest number of billion-dollar storms, floods, droughts and fires of any year since counting began in 1980, with six more than any other year, accounting for inflation.

Comparative Lineament And Geomorphic Analysis Of Chaotic Terrains And Noctis Labyrinthus, Mars, Sarah A. Walton

Electronic Theses and Dissertations

Noctis Labyrinthus (NL) is an extensional trough network connecting the Tharsis rise and Valles Marineris on Mars. Chaotic terrains are a group of polygonally-fractured surface features commonly associated with subsidence due to rapid fluid loss within the subsurface. Polygonal surface patterns are seen at both sites, where geometric topographic highs are bounded by low troughs. Lineaments, topography, and geomorphology of NL and chaotic terrains were analyzed to determine tectonics and fluid influence in the formation and evolution of both sites. NL shows preferential fracture patterns associated with regional extension. Lineaments within chaotic terrains do not show cumulative preferential trends but …

Southern Rio Grande Rift Kinematics And Geochronology, Big Bend Fold Geometry, And The Use Of Real Data In Geoscience Education: Contributions To The Understanding Of Big Bend Geology And To Public Geoscientific Literacy, Jessica Kelsch

Open Access Theses & Dissertations

The Big Bend region of Trans-Pecos Texas preserves a rich record of Rio Grande rifting and Laramide-age contraction that provide intrigue to national and state park visitors and field trips for undergraduate geology students. Despite its well-exposed geologic record, the Big Bend region remains an underutilized natural laboratory for studying these two tectonic events. This dissertation combines structural studies of Rio Grande rift and Laramide structures with public outreach and geoscience education studies focused on the Big Bend region. In Chapter 2, existing extensional-kinematic studies from parts of this region are compiled with new fault kinematic and U-Pb geochronologic data …

Rheological Bridge Zones: A New Perspective To Explore Strain Localization And Rock Rheological Weakening, He Feng

Electronic Theses and Dissertations

Strain localization, a ubiquitous geological phenomenon, emerges when rock undergoes extensive weakening and accommodates disproportionate deformation. This phenomenon spans from brittle faulting to viscous flow, known as shear zones. Despite its prevalence, discussions on weakening primarily center on highly strained samples, rather than the initial deformation state. This research delves into the evolution of localization and rheology in intact rocks.

Heterogeneous mechanical properties within the lithosphere vary based on mineralogy, microstructure, and environmental conditions. Chapter 2 characterizes microscale structures termed "bridge zones." These zones, observed through optical and electron microscopy, exhibit distinctive morphologies. Comprising fine-grained aggregates, bridge zones link weak …

Kinematic Vorticity And Porphyroclast Rotation In Mylonites Of The Norumbega Fault System: Implications For Paleoviscometry, Hendrik Lenferink

Honors College

Crystallographic and shape preferred orientation (SPO) fabrics that develop in mylonitic shear zones can preserve the mean kinematic vorticity number (Wm) of bulk flow. Microstructural methods exploiting dynamically recrystallized quartz and porphyroclast SPO fabrics typically yield conflicting values of Wm. The Sandhill Corner Mylonite Zone of the Norumbega Fault System, Maine, USA, serves as a case study for investigating this discrepancy; Wm estimates range from 0.90 to 1.00 employing the former method (Method 1) and from 0.3 to 0.6 employing the latter method (Method 2). Using a numerical model, I show how a low-viscosity layer (LVL) surrounding clasts affects their …

Migmatite Formation, Geochronometer Petrogeneisis, And Rare Earth Element Mineralization In The Adirondack Mountains, Ny, Kaitlyn Suarez

Doctoral Dissertations

The Adirondack Mountains in upstate New York contain exposures of complex partially melted rocks, in addition to iron oxide-apatite (IOA) deposits with variable rare earth element (REE) concentrations. Previous workers have suggested that melting occurred during the ca. 1150 Ma Shawinigan and the ca. 1050 Ma Ottawan orogenies. However, there are challenges in determining the timing of melting and the number of partial melt events. Further, tectonic models must be developed to describe the petrogenesis of IOA and REE mineralization. Migmatites are present along Rt. 4/22 near Whitehall, NY. In chapter two, all layers of a single migmatitic rock were …

Structural And Kinematic Investigation Of The Dadeville Complex-Brevard Zone Contact (Southern Appalachians): Polyphase Emplacement Of An Allochthonous Terrane On The Laurentian Margin, Andrew Williams

Master's Theses

The Dadeville Complex (DC) lies in the Inner Piedmont of eastern Alabama and western Georgia. The DC formed as a volcanic island arc during the Taconic orogeny (Ordovician Period) and was accreted onto Laurentia during the Acadian orogeny (Devonian-Mississippian Periods); however, the mechanism and role of accretion during the Acadian orogeny is not well constrained. Three proposed emplacement mechanisms for the DC include: (1) orogen-perpendicular translation; (2) orogen-parallel translation; (3) orogenic channel flow.

Today, the DC is a major (over 100 kilometers long) allochthonous terrane composed mostly of meta-igneous rocks. This study investigated structural fabrics and kinematic indicators in the …

Rift-Induced Disruption Of Cratonic Keels Drives Kimberlite Volcanism, Thomas M. Gernon, Stephen M. Jones, Sascha Brune, Thea K. Hincks, Martin Palmer, John C. Schumacher, Rebecca M. Primiceri, Matthew Field, William L. Griffin, Suzanne Y. O'Reilly, Derek Keir, Christopher J. Spencer, Andrew S. Merdith, Anne Glerum

Geology Faculty Publications and Presentations

Kimberlites are volatile-rich, occasionally diamond-bearing magmas that have erupted explosively at Earth’s surface in the geologic past^1,2,3. These enigmatic magmas, originating from depths exceeding 150 km in Earth’s mantle¹, occur in stable cratons and in pulses broadly synchronous with supercontinent cyclicity⁴. Whether their mobilization is driven by mantle plumes⁵ or by mechanical weakening of cratonic lithosphere^4,6 remains unclear. Here we show that most kimberlites spanning the past billion years erupted about 30 million years (Myr) after continental breakup, suggesting an association with rifting processes. Our dynamical …

Polygonal Faults In The Austin Chalk: Invariance Of Scale From Mud Cracks To Polygons With Implications Of Structural, Geomorphic And Isotopic Data On Polygonal Fault Geometry And Origin., Kun Shang

Earth Sciences Theses and Dissertations

The Cretaceous Austin Chalk contains large numbers of fractures and normal faults whose orientations have been attributed to either regional stresses (e.g., the Balcones fault trend) or, by analogy with the mudrocks, to polygonal faulting resulting from compaction. In this study, we present geomorphic data, field study, and stable isotope data to support that the majority of these faults in North Texas are polygonal. Field-measured fault orientations suggest randomly distributed fault strikes, indicating a polygonal fault structure. Using geomorphologic data (topographic and DEM data) on stream orientations suggests that the polygonal fault patterns are best reflected in the headwater (1st …

Impact Of Lithological Variation And Topology On The Connectivity And Intensity Of Fracture Networks In Carbonates, Fahad Qassim

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

Assessing fracture network connectivity in reservoirs remains a challenging task because of the complex nature of fracture networks at various length scales, which significantly impacts fluid flow behavior. Outcrop studies are essential for understanding subsurface fracture networks because intersecting fracture sheets' length, orientation, height distribution, and, therefore, network connectivity and intensity are difficult to measure from wellbores and are typically below seismic resolution. Nevertheless, fracture network connectivity is a crucial parameter and a critical factor in understanding, evaluating, and predicting fluid flow behavior in hydrocarbon reservoirs, aquifers, hazardous waste and CO₂ storage systems, and geothermal energy exploitation. Moreover, fracture …

The Appalachian System Of Basins And Platforms As A Tectonostratigraphic Analogue To The Barents Sea Shelf: Where Arctic Meets The Appalachians, Gustavo De Aguiar Martins

Theses and Dissertations--Earth and Environmental Sciences

Divided between Norway and Russia, the Barents Sea shelf (BSS) is an ~1.4 million km² Arctic province, containing significant hydrocarbon accumulations. However, much of the area is frontier, and geologic data are often restricted or unavailable. One strategy to mitigate lack of geologic data is the use of analogues from well-known, mature basins. Even though there have been attempts to use analogues to study the geology of the BSS, such use is limited. Moreover, no analogue, to my knowledge, has been capable of addressing the regional tectonostratigraphic development of the shelf as a whole.

In this research, the Appalachian …

The Geology Of El Paso, William Cornell, Diane Doser, Richard Langford, Joshua Villalobos, Jason Ricketts

Books & Monographs

The Geology of El Paso describes the history of El Paso, Texas and its surrounding region from the Precambrian formation of the continent to the modern use of geologic resources. This book is written in an easy to digest format, with definitions or links for specific geologic terms and references for further reading. It reviews the formation and evolution of local landmark features such as the Franklin Mountains, Cerro Cristo Rey, and the Sierra de Juarez. Fossils and stratigraphic units of the El Paso area are described as well as important geologic features. The book puts the events that shaped …

Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese

Theses and Dissertations--Earth and Environmental Sciences

Terrestrial paleoseismological records along the Teton fault have historically indicated two-to-three major post-Pinedale (~14 ka) earthquake events, leaving an unresolved 6-9 m offset along the modern scarp. Recent studies of Jenny Lake have augmented this record, but the triggering mechanism is still equivocal until new paleo-earthquake records are developed. The earthquake record of the Teton fault is complicated by quiescence from ~5 ka to present, demonstrating the need for additional paleoseismic investigations. Compressed, high-intensity radar pulse (CHIRP) reflection data from Jackson Lake indicates multiple potentially seismically-induced mass transport deposits (MTDs). At least six MTD Groups representing chronostratigraphic intervals were interpreted …

Integrating Lidar, Aeromagnetic, And Geological Field Data To Identify Structural-Lithologic Elements Within The Archean Carney Lake Gneiss Complex, Ian M. Gannon

Dissertations, Master's Theses and Master's Reports

The Archean Carney Lake Gneiss Complex (CLGC) is a suite of rocks on the southern margin of the Superior Province and within the Minnesota River Valley subprovince. It is one of many gneissic domes in Michigan, Wisconsin, and Minnesota whose complex geology is poorly understood due to a previous lack of economic interest in gneissic terranes and significant challenges to their investigation. As a consequence, the CLGC and other gneissic domes in the region are represented on geologic maps as undifferentiated masses surrounded by better defined and understood Paleoproterozoic supracrustal rocks and igneous intrusions. Within the last ten years, however, …

Structural Analysis And Interpretation Of Deformation Along The Keweenaw Fault System From Lake Linden To Mohawk, Michigan, Nolan G. Gamet

Dissertations, Master's Theses and Master's Reports

The Keweenaw fault is likely the most significant and most studied fault associated with the Midcontinent Rift System. The fault roughly bisects the Keweenaw Peninsula and places Portage Lake Volcanics (~1.1 Ga) over much younger Jacobsville Sandstone (~1.0 Ga). Published bedrock geology maps with cross sections from the 1950s show the fault as a single continuous trace that is locally associated with smaller cross faults and splays. The accompanying cross-sections show hanging-wall volcanic strata having a well-defined, listric geometry with dip decreasing away from the fault to the northwest.

This M.S. thesis presents a structural analysis and interpretation of the …

Structural Analysis And Slip Kinematics Of The Keweenaw Fault System Between Bête Grise Bay And Gratiot Lake, Keweenaw County, Michigan, Daniel J. Lizzadro-Mcpherson

Dissertations, Master's Theses and Master's Reports

The Keweenaw fault is perhaps the most significant geologic structure on the Keweenaw Peninsula, with an estimated 7-11 km of reverse slip juxtaposing volcanic strata of the ~1.1 Ga Portage Lake Volcanics above ~1.0 Ga Jacobsville Sandstone. The fault has been interpreted as a rift-bounding normal fault later inverted by compressional pulses of the Grenville Orogeny or, more recently, as part of a detached thrust fault system unrelated to an earlier normal fault. The fault is shown on published maps as a single continuous fault trace whose sinuosity implies multiple fault segments and complex slip dynamics. Mapping along Bête Grise …

Paleoseismic Investigation Of Rupture On The Dead Coyote Fault In The Kittitas Valley, Washington, Garet Huddleston

All Master's Theses

Recently discovered fault scarps along the Dead Coyote Fault (DCF) in the northern Kittitas Valley (KV) of central Washington suggests active faulting in the late Quaternary, but constraints on the timing and potential magnitude of earthquakes along the fault zone are limited. The KV lies at the northwestern edge of the Yakima Fold and Thrust Belt (YFTB), a low-strain region where individual structures are capable of producing M~7 earthquakes.

This investigation uses surficial geologic mapping and topographic analysis of the DCF scarps, ground penetrating radar transects, and paleoseismic trenching to determine the rupture history of the DCF. The trench was …

Natural, Experimental, And Educational Explorations Of The Interiors Of Terrestrial Planetary Bodies, Nadine L. Grambling

Doctoral Dissertations

Planetary interiors are enigmatic, inaccessible, and vital to the processes that have formed the rocks we see on the surface of bodies in the inner Solar System today. Based on geophysical explorations of the Moon and Earth, along with information gleaned from rocks at the surface today, there is understanding of the basic structure and processes at depth. Using a combination of natural samples and experimental studies, we attempt to learn more about the physical conditions beneath the surface, and their effect on material properties and tectonics processes in the mantle.

On Earth, mid-ocean ridge processes have long been debated, …

Unraveling Deformation Mechanisms And Kinematics In Metasedimentary Rocks Along The Southern Iberian Shear Zone, Kayla P. Kopinski

Theses and Dissertations

The primary goal of this project is to document deformation mechanisms in quartz-rich rocks across a 100 m wide ductile shear zone to evaluate whether strain localization at the brittle-ductile transition is accompanied by variations in active or dominant deformation mechanisms. A secondary goal of this project is to evaluate whether the kinematic framework varies across a shear zone with a major rheological boundary. The Southern Iberian Shear Zone (SISZ), a major terrane bounding shear zone within the Iberian Massif, is an ideal location to study these questions because it is a regional scale shear zone currently exposed at the …

Induced Seismicity In The Raton Basin And Global Variability Of The 410-Km Discontinuity, Margaret E. Glasgow

Earth and Planetary Sciences ETDs

Natural processes like mantle convection and plate tectonics dominate Earth’s seismic structure. Recently human activities have increasingly influenced the deformation of the shallow crust. In this dissertation, passive source seismology was used to constrain seismic discontinuities in the mantle transition zone and seismogenic structures in induced earthquake settings. Using a novel sampling method and uniform processing approach, I found the 410-km discontinuity is thermally and compositionally variable. Using a machine- learning approach, I found the three main zones of seismicity in the Raton Basin consist of short faults or fault segments with variable orientations. The zone that hosted a Mw …

Geochemical Analysis Of Recent Volcanic Ash Blanketing Barbados And Constraints On Magma Composition (V32e-0112), Nazrul I. Khandaker, Krishna Mahabir, Surendranauth Mahabir, Lloyd Kiefer, Juan C. Campo, Andrew M. Singh

Publications and Research

Preliminary field and geochemical investigations were conducted on ash samples from Barbados to chemically characterize and decipher magma chemistry associated with a recent volcanic event. A thick plume of volcanic ash from the La Soufriere Volcano in St Vincent, which erupted on April 9, 2021, caused lower visibility due to ash clouds which engulfed the region for some time. Three authors from the research team visited Barbados during the summer subsequent and completed a reconnaissance investigation on recent ashfall. St Vincent is a small volcanic island in the Eastern Caribbean and lies in the southern part of the Lesser Antilles …

Integrating Remote Digital Tools Into Post-Pandemic Geologic Fieldwork To Effectively Disseminate Content Delivery And Assist In Overall Understanding Of Various Geologic Phenomena: Summer 2022 Field Mapping Exercises, Nazrul I. Khandaker

Publications and Research

INTEGRATING REMOTE DIGITAL TOOLS INTO POST-PANDEMIC GEOLOGIC FIELDWORK TO EFFECTIVELY DISSEMINATE CONTENT DELIVERY AND ASSIST IN OVERALL UNDERSTANDING OF VARIOUS GEOLOGIC PHENOMENA: SUMMER 2022 FIELD MAPPING EXERCISES

SHAMI, Malek, BETHEL, Cherise, NUNEZ, Eddy, RAYHAN, Salam, KHANDAKER, Nazrul and CABAROY, Charren C.

Geological Society of America Abstracts with Programs. Vol 54, No. 5, https://doi.org/10.1130/abs/2022AM-379779

SHAMI, Malek¹, BETHEL, Cherise², NUNEZ, Eddy³, RAYHAN, Salam³, KHANDAKER, Nazrul² and CABAROY, Charren C.¹, (1)Geology Discipline, AC-2F09, York College of CUNY, 9420 Guy R. Brewer Blvd., Jamaica, NY 11451, (2)Geology Discipline, York College of CUNY, …

Deformation Conditions Of Quartz-Rich Mylonites Of The Grenville Front Tectonic Zone And Application To The Crustal Strength, Xueke Chang

Electronic Thesis and Dissertation Repository

This thesis analyzes a suite of mylonites from the Grenville Front shear zone exposed southeast of Sudbury, Ontario. Lattice preferred orientations, titanium-in-quartz thermometer, and dynamically recrystallized grain size piezometer measurements were applied to obtain the deformation mechanisms, deformation temperatures (T), and differential stresses (σ), respectively. Results show that these mylonites were formed in the shear zone during the terminal stage of the Grenville Orogeny. The dominant deformation mechanism is by regime 2 dislocation creep. The deformation temperature is between 425-567 °C, and the differential stress is between 56-133 MPa. These results are discussed in the context of wet quartzite flow …

Emplacement Of The Dadeville Complex Of The Southernmost Inner Piedmont Within The 7.5 Min. Cusseta Quadrangle, Chambers County, Alabama: Channel Flow, Klippe Kinematics, Or Orogen Parallel Translation, Timothy Black

Master's Theses

The Appalachian Mountains have a complex geologic history spanning three orogenic periods, the Taconic, the Acadian/Neoacadian, and Alleghanian orogenies. The Inner Piedmont of the Appalachian Mountains within Alabama contains two distinct lithologic complexes, the Dadeville Complex, and the Opelika Complex separated by the Stonewall Line. These complexes were formed during an arc-back arc fringing system during the Taconic orogeny and emplaced and recorded peak metamorphism during the Acadian orogeny.

The Dadeville Complex is an allochthonous arc terrain built on extended Laurentian crust. The mode of transportation and accretion after formation is not well understood, which has implications for the role …

Processing Seismic, Gravity And Magnetic Data Over Diebold Knoll On Juan De Fuca Plate, Md Ariful Islam, Irina Filina

UNL Student Research Days Posters, Graduate

The Juan de Fuca plate is subducting beneath the North American plate along the Cascadia Subduction Zone. The CSZ is associated with multiple earthquakes, although compared to other subduction zones, it is less active. Many studies suggest that subduction will cause major mega thrust earthquake in near future, while others oppose this view. This project is focused on the Diebold Knoll on the JdF plate Various geophysical methods will be integrated to determine its origin and tectonic history.

Influence Of Bedrock Erodibility On Orogen Evolution In Collisional Systems And Implications For Geodynamic Models, Stephanie Ann Sparks

Theses and Dissertations--Earth and Environmental Sciences

Theoretical and numerical geodynamic models of continental collisional systems often involve, either explicitly or implicitly, a necessary yet complicated dependence between tectonics and erosion; however, the exact nature of these relationships remains elusive and controversial. In such models for the Himalayan-Tibetan (H-T) collisional orogen, surface processes are theorized or in some cases required to play an essential role in modulating critical processes active in the evolution of that system. To investigate, at least to first order. these interactions between climate and tectonics, we generate a simplified landscape evolution model of an actively uplifting orogenic wedge acted upon by surface processes. …

Syn- To Post-Orogenic Evolution Of Collisional Mountain Systems: Investigating The Potential For Crustal Flow Using Thermochronology And Numerical Models, Brandon Spencer

Theses and Dissertations--Earth and Environmental Sciences

This dissertation is composed of three distinct manuscripts which collectively investigate processes that contribute to the late evolution of collisional mountain systems —specifically, the ancient Appalachian-Caledonian system. In the first paper, ⁴⁰Ar/³⁹Ar thermochronological data are used to constrain the timing of exhumation of the Scandian orogenic wedge of northern Scotland. Muscovite and amphibole samples yield dates of ca. 420-411 Ma, consistent with cooling after peak orogenesis. During this cooling phase, dates from both systems in individual thrust sheets show an increase in cooling rate in the later stage of exhumation; in the orogenic core, the cooling rate …

Deformation Of Wall Rocks And Overburden Sequences Proximal To Salt Diapirs In Salt Valley, Utah: Implications For Predicting Subseismic Damage In Salt Tectonic Systems, William Swanger

Theses and Dissertations--Earth and Environmental Sciences

Although deformation related to salt tectonics is generally considered to be an ancillary field of structural geology, owing to its relatively limited occurrence in the geologic record, the preponderance of salt-involved systems in multiple hydrocarbon-rich basins around the world (e.g., Gulf of Mexico, Atlantic passive margins, Iran, etc.) creates a necessity for understanding salt-related deformation. Traditionally, salt was considered to be relatively weak and thus was mostly unable to drive deformation of adjacent wall rocks and cover sequences. However, a number of recent numerical modeling studies have shown that mobilized and pressurized salt may have the ability to actively pierce …

Viscous Anisotropy Of Wet Olivine Aggregates, Megan Ryan

Williams Honors College, Honors Research Projects

I will deform natural olivine aggregates (Anita Bay dunite) cores in various orientations relative to a natural mineral alignment in the rock under both dry and wet conditions. Different orientations in regards to this mineral alignment will produce deformation on different slip systems. Stress measurements will be taken during the deformation of the samples in order to characterize any changes in viscous anisotropy observed due to the changes in slip system. Anita Bay dunite is a proxy for the main mineral found in the mantle wedge of subduction zones. Therefore, understanding the transformation of viscosity and slip systems in this …