Geology Commons^™

Evidence Of Repeated Wildfires Prior To Human Occupation On San Nicolas Island, California, Jeffrey S. Pigati, John P. Mcgeehin, Gary L. Skipp, Daniel R. Muhs

United States Geological Survey: Staff Publications

Understanding how early humans on the California Channel Islands might have changed local fire regimes requires a baseline knowledge of the frequency of natural wildfires on the islands prior to human occupation. A sedimentary sequence that was recently discovered in a small canyon on San Nicolas Island contains evidence of at least 24 burn events that date to between ~37 and 25 ka (thousands of calibrated ¹⁴C years before present), well before humans entered North America. The evidence includes abundant macroscopic charcoal, blackened sediments, and discrete packages of oxidized, reddish-brown sediments that are similar in appearance to sedimentary features …

Simultaneous Adsorption Of 11 Volatile Organic Compounds By An Activated Carbon Made From Polystyrene Sulfonic Acid-Based Organic Salt, Alejandro Smith

Dissertations and Theses

Activated carbon is used in water treatment worldwide due to its ability to adsorb many different contaminants from water. The high adsorption capacity of activated carbon is linked to its high internal surface area and micro/meso- porosity. In this work an activated carbon obtained from polystyrene sulfonic acid-based organic salt was examined to simultaneously adsorb eleven volatile organic compounds from aqueous solution. Adsorption data were modeled with different isotherms to determine the equilibrium adsorptive capacities for these compounds. The performance of the polymer-based activated carbon was then compared with that of a commercial wood-based activated carbon. The results indicate that …

Geoneutrino Production Of The Northern Black Hills, South Dakota, United States Of America, Eric Eric Zimney

Theses and Dissertations

Current neutrino observatories operate underground to isolate the detector from cosmic rays and background radiation. However, background radiation from local sources has yet to be accounted for. Current models for neutrino contributions from terrestrial rocks are formulated from bulk compositional estimates of the whole Earth. To better understand local background radiation from geologic sources surfaces rocks were collected throughout the area surrounding the Homestake Mine, South Dakota, home of the Sanford Underground Research Laboratory. The surface rocks were analyzed for radioactivity and neutrino luminosity, producing heat maps indicating the levels of neutrino production throughout the area. The area around the …

Investigation Of Strategies To Promote Effective Teacher Professional Development Experiences In Earth Science, Carol A. Engelmann

Dissertations, Master's Theses and Master's Reports - Open

This dissertation serves as a call to geoscientists to share responsibility with K-12 educators for increasing Earth science literacy. When partnerships are created among K-12 educators and geoscientists, the synergy created can promote Earth science literacy in students, teachers, and the broader community. The research described here resulted in development of tools that can support effective professional development for teachers. One tool is used during the planning stages to structure a professional development program, another set of tools supports measurement of the effectiveness of a development program, and the third tool supports sustainability of professional development programs. The Michigan Teacher …

Doing More With Short Period Data: Determining Magnitudes From Clipped And Over-Run Seismic Data At Mount St. Helens, John J. Wellik Ii

Dissertations, Master's Theses and Master's Reports - Open

How can we calculate earthquake magnitudes when the signal is clipped and over-run? When a volcano is very active, the seismic record may saturate (i.e., the full amplitude of the signal is not recorded) or be over-run (i.e., the end of one event is covered by the start of a new event). The duration, and sometimes the amplitude, of an earthquake signal are necessary for determining event magnitudes; thus, it may be impossible to calculate earthquake magnitudes when a volcano is very active. This problem is most likely to occur at volcanoes with limited networks of short period seismometers. This …

Static And Dynamic Stress Change At 27 Volcanoes Of The Central American Volcanic Arc After The Mw. 7.6 Costa Rica Earthquake Of 5 September 2012, Lorenzo Gratton

Dissertations, Master's Theses and Master's Reports - Open

Large earthquakes may strongly influence the activity of volcanoes through static and dynamic processes. In this study, we quantify the static and dynamic stress change on 27 volcanoes in Central America, after the M_w 7.6 Costa Rica earthquake of 5 September 2012. Following this event, 8 volcanoes showed signs of activity. We calculated the static stress change due to the earthquake on hypothetical faults under these volcanoes with Coulomb 3.3. For the dynamic stress change, we computed synthetic seismograms to simulate the waveforms at these volcanoes. We then calculated the Peak Dynamic Stress (PDS) from the modeled peak ground …

Fault Morphology Within The Southern Kenyan Portion Of The East African Rift Valley, Justin B. Wargelin

Dissertations, Master's Theses and Master's Reports - Open

Faults form quickly, geologically speaking, with sharp, crisp step-like profiles. Logic dictates that erosion wears away this "sharpness" or angularity creating more rounded features. As erosion occurs, debris accumulates at the base of the scarp slope. The stable end point of this process is when the scarp slope approaches an ideal sigmoid shape.

This theory of fault end process, in combination with a new method developed in this report for fault profile delineation, has the potential to enable observation and categorization of fault profiles over large, diverse swaths of fault formation-- in remote areas such as the Southern Kenyan Rift …

Did A Submarine Landslide Contribute To The 2011 Tohoku Tsunami?, David R. Tappin, Stephan T. Grilli, Jeffrey C. Harris, Robert J. Geller, Timothy Masterlark, James T. Kirby, Fengyan Shi, Gangfeng Ma, K.K.S. Thingbaijam, P. Martin Mai

Civil & Environmental Engineering Faculty Publications

Many studies have modeled the Tohoku tsunami of March 11, 2011 as being due entirely to slip on an earthquake fault, but the following discrepancies suggest that further research is warranted. (1) Published models of tsunami propagation and coastal impact underpredict the observed runup heights of up to 40. m measured along the coast of the Sanriku district in the northeast part of Honshu Island. (2) Published models cannot reproduce the timing and high-frequency content of tsunami waves recorded at three nearshore buoys off Sanriku, nor the timing and dispersion properties of the waveforms at offshore DART buoy #21418. (3) …

Seismic Anisotropy And Mantle Flow Beneath Africa And Arabia, Ahmed Abdalla Elsheikh

Doctoral Dissertations

"In spite of numerous studies, the mechanisms for the rifting, uplifting, and volcanism on the African plate remain enigmatic. The most popular hypotheses proposed for explaining these tectonic phenomena involve edge-driven small-scale mantle convection and the thermal or dynamic effects of one or more mantle plumes. In this study we use continental scale shear-wave splitting (SWS) measurements to provide additional constraints on the various models of rifting, uplifting, and volcanism of the Cameroon Volcanic Line (CVL) and the Arabian plate. The splitting of P-to-S converted phases at the core-mantle boundary on the receiver side (XKS including PKS, SKKS, and SKS) …

Biomineralization Of Carbonates In Modern Microbial Sediments And Its Implications For Co₂ Sequestration, Varun Gnanaprian Paul

Doctoral Dissertations

"Several bacterial species influence carbonate mineral precipitation by modifying pH, alkalinity, Ca²⁺ activity and by providing nucleation sites for mineralization. Two studies have been undertaken to explore microbial influence in the mineralization of carbonates. In the first study, the ability of sulfate-reducing bacteria (SRB) to induce carbonate mineralization was investigated as a means to enhance mineral sequestration of CO₂. Sulfate-reducing bacteria enriched from hypersaline Storr's Lake, The Bahamas; Lake Estancia, New Mexico; and Great Salt Plains Lake, Oklahoma, were tested in reactors under varying CO₂ concentrations. Carbonate mineral precipitation was achieved only in reactors with Lake Estancia SRB community and …

Study Of Filled Dolines By Using 3d Stereo Image Processing And Electrical Resistivity Imaging, Mateja Breg Valjavec

International Journal of Speleology

This article deals with doline degradation due to uncontrolled waste dumping in the past in the Logatec Polje in Slovenia. It introduces a concept for determining 3D geometric characteristics (shape, depth, radius, area, and volume) of formerly concave landforms (i.e., recently filled dolines) by using a combination of two methods: (1) photogrammetric stereo processing of archival aerial photographs and (2) electrical resistivity imaging (ERI). To represent, visualize, and study the characteristics of the former surface morphology (i.e., the dolines before they were filled), a digital terrain model (DTM) for 1972 (DTM1972) was made using digital photogrammetry processing of five sequential …

Upper Pleistocene And Holocene Palaeoenvironmental Records In Cueva Mayor Karst (Atapuerca, Spain) From Different Proxies: Speleothem Crystal Fabrics, Palynology And Archaeology., Virginia Martínez-Pillado, Arantza Aranburu, Juan Luis Arsuaga, Blanca Ruiz-Zapata, Maria José Gil-García, Heather Stoll, Iñaki Yusta, Eneko Iriarte, José Miguel Carretero, R. Lawrence Edwards, Hai Cheng

International Journal of Speleology

The Cueva Mayor karst system of Atapuerca, in Northern Spain, hosts a highly significant record of human occupation from the Pleistocene. The climatic context of the human activities during the Pleistocene-Holocene for this inland site has not been well constrained, since existing records of the palaeoclimatic evolution of the Northern Iberian Peninsula are from more distal coastal and high-elevation sites. In this study, we interpret the palaeoenvironmental information recorded on the petrography of a stalagmite and the pollen spectra of the Sierra de Atapuerca karst system during the last 20 kyr. The integration of both types of records has allowed …

Electron Donor Contributions To Denitrification In The Elk Valley Aquifer, North Dakota, Amanda M. Krieger

Theses and Dissertations

Six denitrification tracer tests were performed over eight and a half years in in situ mesocosms (ISMs) in the Elk Valley Aquifer (EVA) in east-central North Dakota. Groundwater samples were analyzed to determine how much nitrate was lost beyond that explained by dilution of the bromide tracer. Additional losses were attributed to denitrification. The denitrification rates varied from 0.10 to 0.23 mg N/L/day for the six tests. In general, the major electron donors for denitrification are organic carbon (OC), pyrite (FeS2), and ferrous iron silicate minerals. In the EVA tracer tests, increases in sulfate indicated that the oxidation of pyrite …

Calcite Dissolution Under Turbulent Flow Conditions: A Remaining Conundrum, Matthew D. Covington

Geosciences Faculty Publications and Presentations

A significant body of experimental and theoretical work has examined the dissolution rates of calcite, and other carbonate minerals, under varying chemical and hydrodynamic conditions (see Morse & Arvidson (2002) for a comprehensive review). The relationships derived from this work have been applied extensively to the development of mechanistic models of speleogenesis (e.g. Dreybrodt 1996; Dreybrodt et al. 2005; Birk et al. 2005; Rehrl et al. 2008; Kaufmann 2009; Szymczak & Ladd 2011). However, the primary focus of these models has been on the early stages of cave formation, with less attention toward the later stages of cave evolution and …

Classification Of Four Meteorite Samples, Karla Farley

University Honors Theses

The petrography, mineralogy, and mineral chemistry of four unclassified Northwest Africa meteorites in the Cascadia Meteorite Laboratory collection (CML0005, 0023, 0024, 0032) were studied using optical microscopy and scanning electron microscopy. The data will be used to classify the meteorites and to obtain official names for the meteorites. CML0023 has the preliminary classification of L6 (S3) W1, CML0024 has L6 (S3) W1, and CML0032 has L6 (S2) W1. CML0005 has chemistry and mineralogy that indicate it is an anomalous acapulcoite.

A Tree-Ring Based Reconstruction Of Logan River Streamflow, Northern Utah, Eric B. Allen, Tammy M. Rittenour, R. Justin Derose, Matthew F. Bekker, Roger Kjelgren, Brendan M. Buckley

Geosciences Faculty Publications

We created six new tree‐ring chronologies in northern Utah, which were used with preexisting chronologies from Utah and western Wyoming to reconstruct mean annual flow for the Logan River, the largest tributary of the regionally important Bear River. Two reconstruction models were developed, a “Local” model that incorporated two Rocky Mountain juniper chronologies located within the basin, and a “Regional” model that also included limber pine and pinyon pine chronologies from a larger area. The Local model explained 48.2% of the variability in the instrumental record and the juniper chronologies better captured streamflow variability than Douglas‐fir collected within the Logan …

Geology Of The Birdseye 7.5-Minute Quadrangle, Utah County, Utah:Â Implications For Mid-Cenozoic Extension And Deposition Of The Moroni Formation, Don L. Bagshaw

Theses and Dissertations

Geologic structures within the Birdseye 7.5 minute quadrangle Utah County, Utah have been related by previous workers to both the Jurassic Arapien Shale diapirism and to the mid-Cenozoic extensional collapse of the Charleston-Nebo Thrust. Whichever model proves valid, it will have implications for oil exploration and interpretation of the subsurface geologic structure in the region. A detailed map of the quadrangle was constructed to better constrain which mechanism was responsible for the deformation. Exposures of Arapien Shale near, and within the Birdseye quadrangle show no evidence of diapiric movement. Arapien involvement in the deformation of Tertiary rocks in the center …

Digital Outcrop Model And Paleoecology Of The Eight-Foot Rapid Algal Field (Middle Pennsylvanian Lower Ismay Sequence), Paradox Basin, Utah, Colton Lynn Goodrich

Theses and Dissertations

Although phylloid algal mounds have been studied for 50 year, much remains to be determined concerning the ecology and sedimentology of these Late Paleozoic carbonate buildups. Herein we perform a digital outcrop study of the well-known Middle Pennsylvanian Lower Ismay mound interval in the Paradox Basin because outcropping mounds along the San Juan River are cited as outcrop analogs of reservoir carbonates in the Paradox Basin oil province of Utah and adjacent states. The principal field area is the Eight Foot algal field located at river mile 19.2 on the San Juan River, approximately 14 miles SSW of Bluff, Utah. …

The Crustal Thickness Of West Antarctica, Julien A. Chaput, Richard C. Aster, Audrey D. Huerta, X. Sun, Andrew Lloyd, Douglas A. Wiens, Andrew Nyblade, Sridhar Anandakrishnan, J. Paul Winberry, Terry Wilson

Geological Sciences Faculty Scholarship

P-to-S receiver functions (PRFs) from the Polar Earth Observing Network (POLENET) GPS and seismic leg of POLENET spanning West Antarctica and the Transantarctic Mountains deployment of seismographic stations provide new estimates of crustal thickness across West Antarctica, including the West Antarctic Rift System (WARS), Marie Byrd Land (MBL) dome, and the Transantarctic Mountains (TAM) margin. We show that complications arising from ice sheet multiples can be effectively managed and further information concerning low-velocity subglacial sediment thickness may be determined, via top-down utilization of synthetic receiver function models. We combine shallow structure constraints with the response of deeper layers using a …

Marine Diatom Assemblage Variation Across Pleistocene Glacial–Interglacial Transitions And Neogene Diatom Biostratigraphy Of Site C9001, Nw Pacific Ocean, Marcella K. Purkey

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

In 2006, D/V-Chikyu cruise CK06-06 drilled Hole C9001C at Site C9001 in the Northwest Pacific Ocean, 80 km east of the Shimokita Peninsula, Japan. An existing chronostratigraphic framework provides a continuous glacial-interglacial (GI) climate record from which a diatom record of paleoenvironmental changes was developed across several GI cycles. Species counts, diatom temperature values, calculated sea-surface temperatures (SST) and factor analysis were produced for each sample and calibrated to prior diatom studies in this region. These features were used to characterize and compare interglacial maxima of Marine Isotope Stages (MIS) 1, 5e, 9 and 11 and transitions from the preceding …