Geology Commons^™

A4: Possible Post-Laurentide Cirque Glaciation In The Great Gulf Presidential Range, New Hampshire, Brian Fowler, Dulin Ian

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 81-94.

A1: Lithium-Boron-Beryllium Gem Pegmatites, Oxford Co., Maine: Havey And Mount Mica Pegmatites, William B. Simmons, Alexander U. Falster, Karen L. Webber, Myles M. Felch, Dwight C. Bradley

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 1-34.

Guidebook For Field Trips In Western Maine And Northern New Hampshire, Beverly Johnson, J. Dykstra Eusden

New England Intercollegiate Geological Conference 2017

New England Intercollegiate Geological Conference, 109th Annual Meeting, September 29 - October 1, 2017, Bethel, Maine, 345 p, color.

Assessment Of Thermal Maturity Trends In Devonian–Mississippian Source Rocks Using Raman Spectroscopy: Limitations Of Peak-Fitting Method, Jason S. Lupoi, Luke P. Fritz, Thomas M. Parris, Paul C. Hackley, Logan Solotky, Courtland F. Eble, Steve Schlaegle

Faculty, Staff, and Affiliated Publications--KGS

The thermal maturity of shale is often measured by vitrinite reflectance (VRo). VRo measurements for the Devonian–Mississippian black shale source rocks evaluated herein predicted thermal immaturity in areas where associated reservoir rocks are oil-producing. This limitation of the VRo method led to the current evaluation of Raman spectroscopy as a suitable alternative for developing correlations between thermal maturity and Raman spectra. In this study, Raman spectra of Devonian–Mississippian black shale source rocks were regressed against measured VRo or sample-depth. Attempts were made to develop quantitative correlations of thermal maturity. Using sample-depth as a proxy for thermal maturity is not without …

Characteristics Of Deep Crustal Seismic Anisotropy From A Compilation Of Rock Elasticity Tensors And Their Expression In Receiver Functions, Sarah J. Brownlee, Vera Schulte-Pelkum, Anissha Raju, Kevin Mahan, Cailey Condit, Omero Felipe Orlandini

Environmental Science and Geology Faculty Research Publications

Rocks in the continental crust are long lived and have the potential to record a wide span of tectonic history in rock fabric. Mapping rock fabric in situ at depth requires the application of seismic methods. Below depths of microcrack closure seismic anisotropy presumably reflects the shape and crystallographic preferred orientations influenced by deformation processes. Interpretation of seismic observables relevant for anisotropy requires assumptions on the symmetry and orientation of the bulk elastic tensor. We compare commonly made assumptions against a compilation of 95 bulk elastic tensors from laboratory measurements, including electron backscatter diffraction and ultrasound, on crustal rocks. The …

Aeromagnetic, Gravity, And Differential Interferometric Synthetic Aperture Radar Analyses Reveal The Causative Fault Of The 3 April 2017 MW 6.5 Moiyabana, Botswana, Earthquake, Folarin Kolawole, Estella A. Atekwana, S. Malloy, Dorothy Sarah Stamps, Raphael Grandin, Mohamed G. Abdel Salam, Khumo Leseane, Elisha M. Shemang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

On 3 April 2017, a M_w 6.5 earthquake struck Moiyabana, Botswana, nucleating at >20 km focal depth within the Paleoproterozoic Limpopo-Shashe orogenic belt separating the Archean Zimbabwe and Kaapvaal Cratons. We investigate the lithospheric structures associated with this earthquake using high-resolution aeromagnetic and gravity data integrated with Differential Interferometric Synthetic Aperture Radar (DInSAR) analysis. Here we present the first results that provide insights into the tectonic framework of the earthquake. The ruptured fault trace delineated by DInSAR aligns with a distinct NW striking and NE dipping magnetic lineament within the Precambrian basement. The fault plane solution and numerical modeling …

Constraining The Holocene Extent Of The Northwest Meers Fault, Oklahoma Using High-Resolution Topography And Paleoseismic Trenching, Kristofer Tyler Hornsby

Dissertations and Theses

The Meers Fault (Oklahoma) is one of few seismogenic structures with Holocene surface expression in the stable continental region of North America. Only the ~37 km-long southeastern section of the ~55 km long Meers Fault is interpreted to be Holocene-active. The ~17 km-long northwestern section is considered to be Quaternary-active (pre-Holocene); however, its low-relief geomorphic expression and anthropogenic alteration have presented difficulties in evaluating the fault length and style of Holocene deformation. We reevaluate surface expression and earthquake timing of the northwestern portion of the Meers Fault to improve fault characterization, earthquake rupture models, and seismic hazard evaluations based on …

Compositional And Physical Gradients In The Magmas Of The Devine Canyon Tuff, Eastern Oregon: Constraints For Evolution Models Of Voluminous High-Silica Rhyolites, Shelby Lee Isom

Dissertations and Theses

Large-volume silicic ignimbrites erupt from reservoirs that vary in composition, temperature, volatile content and crystallinity. The 9.7 Ma Devine Canyon Tuff (DCT) of eastern Oregon is a large-volume (>250 km³), compositionally zoned and variably welded ignimbrite. The ignimbrite exhibits heterogeneous trace element compositions, variable volatile content and crystallinity. These observations were utilized in the investigation into the generation, accumulation and evolution of the magmas composing the DCT. Building off previous research, pumices were selected from the range of trace element compositions and analyzed with respect to crystallinity, mineral abundances and assemblages. The DCT displays a gradational trace …

Climate, Wildfire, And Erosion Ensemble Foretells More Sediment In Western Usa Watersheds, John B. Sankey, Jason Kreitler, Todd J. Hawbaker, Jason L. Mcvay, Mary Ellen Miller, Erich R. Mueller, Nicole M. Vaillant, Scott E. Lowe, Temuulen T. Sankey

Michigan Tech Research Institute Publications

The area burned annually by wildfires is expected to increase worldwide due to climate change. Burned areas increase soil erosion rates within watersheds, which can increase sedimentation in downstream rivers and reservoirs. However, which watersheds will be impacted by future wildfires is largely unknown. Using an ensemble of climate, fire, and erosion models, we show that postfire sedimentation is projected to increase for nearly nine tenths of watersheds by >10% and for more than one third of watersheds by >100% by the 2041 to 2050 decade in the western USA. The projected increases are statistically significant for more than eight …

Melting In The Mantle Wedge: Quantifying The Effects Of Crustal Morphology And Viscous Decoupling On Melt Production With Application To The Cascadia Subduction Zone, Jiaming Yang

Dissertations and Theses

Arc magmatism is sustained by the complex interactions between the subducting slab, the overriding plate, and the mantle wedge. Partial melting of mantle peridotite is achieved by fluid-induced flux melting and decompression melting due to upward flow. The distribution of melting is sensitive to temperature, the pattern of flow, and the pressure in the mantle wedge. The arc front is the surface manifestation of partial melting in the mantle wedge and is characterized by a narrow chain of active volcanoes that migrate in time. The conventional interpretation is that changes in slab dip angle lead to changes in the arc …

Reference Data Set Of Volcanic Ash Physicochemical And Optical Properties, A. Vogel, S. Diplas, A. J. Durant, A. S. Azar, M. F. Sunding, William I. Rose, A. Sytchkova, C. Bonadonna, K. Krüger, A. Stohl

Department of Geological and Mining Engineering and Sciences Publications

Uncertainty in the physicochemical and optical properties of volcanic ash particles creates errors in the detection and modeling of volcanic ash clouds and in quantification of their potential impacts. In this study, we provide a data set that describes the physicochemical and optical properties of a representative selection of volcanic ash samples from nine different volcanic eruptions covering a wide range of silica contents (50–80 wt % SiO₂). We measured and calculated parameters describing the physical (size distribution, complex shape, and dense-rock equivalent mass density), chemical (bulk and surface composition), and optical (complex refractive index from ultraviolet to …

Desert Pool {If Every Desert Was Once A Sea}, Karen Miranda Abel

The Goose

Desert Pool {If every desert was once a sea} is a site-specific art project by Canadian artist Karen Miranda Abel completed in 2016 while artist-in-residence at Joya: arte + ecología, an arts-led research centre situated in an alpine desert within a national park in southern Spain. The elemental installation represents an envisioning of the ancient sea that occupied the Sierra de María-Los Vélez Natural Park millions of years before the current desert ecology, a time when its highest mountain peaks may have been islands.

40ar/39ar Ages And Zircon Petrochronology For The Rear Arc Of The Izu-Bonin-Marianas Intra-Oceanic Subduction Zone, Graham Dm Andrews

Faculty & Staff Scholarship

Long-lived intra-oceanic arcs of Izu-Bonin-Marianas (IBM)-type are built on thick, granodioritic crust formed in the absence of pre-existing continental crust. International Ocean Discovery Program Expedition 350, Site U1437, explored the IBM rear arc to better understand continental crust formation in arcs. Detailed petrochronological (U–Pb geochronology combined with trace elements, oxygen and hafnium isotopes) characterizations of zircon from Site U1437 were carried out, taking care to exclude potential contaminants by (1) comparison of zircon ages with ship-board palaeomagnetic and biostratigraphic ages and 40Ar/39Ar geochronology, (2) analysing zircon from drill muds for comparison, (3) selectively carrying out in situ analysis in petrographic …

Field Mapping Investigation And Geochemical Analysis Of Volcanic Units Within The Dinner Creek Tuff Eruptive Center, Malheur County, Eastern Oregon, Matthew Cruz

Dissertations and Theses

The Dinner Creek Tuff is a mid-Miocene rhyolitic to dacitic ignimbrite, consisting of four cooling units with ⁴⁰Ar/³⁹Ar ages 16--15 Ma. Previous geologists have suspected that the source of the tuff is located in northwestern Malheur County, eastern Oregon. This broad area is called the Dinner Creek Tuff Eruptive Center.

This thesis summarizes field work, XRF/ICP-MS geochemistry, thin section petrography, and SEM feldspar analysis from the summers of 2015 and 2016. The main purpose of this study is to identify sources for the Dinner Creek Tuff units within the Dinner Creek Tuff Eruptive Center. The secondary purpose …

Need For A Large-N Array (And Wavelets And Differences) To Determine The Assumption-Free 3-D Earth Model, Solymar Ayala Cortez, Aaron A. Velasco, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the main objectives of geophysical seismic analysis is to determine the Earth's structure. Usually, to determine this structure, geophysicists supplement the measurement results with additional geophysical assumptions. An important question is: when is it possible to reconstruct the Earth's structure uniquely based on the measurement results only, without the need to use any additional assumptions? In this paper, we show that for this, one needs to use large-N arrays -- 2-D arrays of seismic sensors. To actually perform this reconstruction, we need to use differences between measurements by neighboring sensor and we need to apply wavelet analysis to …

East African Weathering Dynamics Controlled By Vegetation-Climate Feedbacks, Sarah J. Ivory, Michael M. Mcglue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen

Earth and Environmental Sciences Faculty Publications

Tropical weathering has important linkages to global biogeochemistry and landscape evolution in the East African rift. We disentangle the influences of climate and terrestrial vegetation on chemical weathering intensity and erosion at Lake Malawi using a long sediment record. Fossil pollen, microcharcoal, particle size, and mineralogy data affirm that the detrital clays accumulating in deep water within the lake are controlled by feedbacks between climate and hinterland forest composition. Particle-size patterns are also best explained by vegetation, through feedbacks with lake levels, wildfires, and erosion. We develop a new source-to-sink framework that links lacustrine sedimentation to hinterland vegetation in tropical …

North Dakota Carbonsafe – A Feasibility Study, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Carbon Storage Assurance Facility Enterprise (CarbonSAFE) project, which offers clean, safe, and affordable energy throughout North Dakota. Includes information on carbon capture, including geological storage, and the U.S. Department of Energy’s involvement. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Coastal Eolian Sand-Ramp Development Related To Paleo-Sea-Level Changes During The Latest Pleistocene And Holocene (21–0 Ka) In San Miguel Island, California, U.S.A., Curt D. Peterson, Jon M. Erlandson, Errol Stock, Steve W. Hostetler, David M. Price

Geology Faculty Publications and Presentations

Coastal eolian sand ramps (5–130 m elevation) on the northern slope (windward) side of the small San Miguel Island (13 km in W-E length) range in age from late Pleistocene to modern time, though a major hiatus in sand-ramp growth occurred during the early Holocene marine transgression (16–9 ka). The Holocene sand ramps (1–5 m measured thicknesses) currently lack large dune forms, thereby representing deflated erosional remnants, locally covering thicker late Pleistocene sand-ramp deposits. The ramp sand was initially supplied from the adjacent island-shelf platform, extending about 20 km north of the present coastline. The sand-ramp deposits and interbedded loess …

Collaborative Research: Facet: Quantifying The Topographic Response To Tectonic Processes In Southern Taiwan, Tammy M. Rittenour

Funded Research Records

No abstract provided.

Conduction Plus Convection Heat Flow Modeling For The Linga Complex, Peruvian Coastal Batholith, Luciano Uriel González Olivares

Loma Linda University Electronic Theses, Dissertations & Projects

Factors affecting the thermal evolution of the Linga magmatic intrusion in the Ica-Pisco area of the Peruvian Coastal Batholith were studied using field work, petrography, geochemistry data, and computer modeling. Field work and petrography involved collecting samples for geochemical analysis and documenting widespread propylitic and potassic hydrothermal alteration. Major element geochemistry was used to estimate rock density, viscosity, liquidus temperature, and water content. The δ18O values of seven fresh samples showed a slightly increasing west-east and old-young trend of approximately 7-8‰, indicating an increasing crustal component. The δ18O and δD values for eleven altered samples indicated that alteration came mostly …