Controls On Joint Formation During Glacial Unloading Of The Sharon Sandstone At Gorge Metropark, Akron, Ohio,
2016
The University of Akron
Controls On Joint Formation During Glacial Unloading Of The Sharon Sandstone At Gorge Metropark, Akron, Ohio, Abigail N. Ritter
Williams Honors College, Honors Research Projects
The transition between significantly different materials is known to inhibit crack propagation, i.e. automobile glass, machinable ceramics and joints in different lithologies. In order to determine if a significant material transition, or a surface, such as a bedding plane, has a greater impact on inhibiting joint formation, I investigated discontinuous joints that formed during glacial unloading of the Sharon Sandstone, which is exposed at Gorge Metropark in Akron, Ohio. The Sharon Sandstone is a medium grained quartz arenite of Early Pennsylvanian age with significant cross-bedding, and contains many continuous (i.e. through-going), and discontinuous, joints in similar orientations. Stress fields created …
Lower Mississippian Chert Development, Southern Midcontinent Region,
2016
University of Arkansas, Fayetteville
Lower Mississippian Chert Development, Southern Midcontinent Region, J. M. Cains, A. Potra, E. D. Pollock
Journal of the Arkansas Academy of Science
The Lower Mississippian Boone Formation is a chert-bearing, fossiliferous limestone typically 100-115m. thick forming the Springfield Plateau across the tri-state region of northwestern Arkansas, southwestern Missouri, and northeastern Oklahoma. The Boone represents the maximum flooding, highstand, and regressive intervals of a single, third order transgressive-regressive carbonate cycle bounded by regional unconformities. Two types of chert occur in this formation, and provide the basis for subdivision of the Boone into informal lower and upper members in northern Arkansas. The lower Boone represents early Osagean maximum flooding conditions and consists of calcisiltites with interbedded dark, nodular chert. This chert exhibits compaction phenomena …
Age And Correlation Of The Moorefield Shale (Upper Mississippian) In Its Type Area, Northeastern Arkansas,
2016
University of Arkansas, Fayetteville
Age And Correlation Of The Moorefield Shale (Upper Mississippian) In Its Type Area, Northeastern Arkansas, O. Dalu, W. S. Coffey, W. L. Manger
Journal of the Arkansas Academy of Science
The name Moorefield was proposed by Adams and Ulrich (1904) for exposures of gray to brown, phosphatic shale with a basal limestone, overlying the Lower Mississippian Boone Formation, and underlying the Upper Mississippian Batesville Sandstone, in the vicinity of Moorefield, Independence County, northeastern Arkansas. Gordon (1944) 1) restricted the name Moorefield to the lower limestone-bearing interval, 2) applied a new name, Ruddell, to the succeeding shale section that comprises the bulk of the interval, with a type area near Moorefield, and 3) interpreted the interval contacts as unconformities. The name Ruddell was used for the revised Geological Map of Arkansas …
Geotherms From The Temperature-Depth–Constrained Solutions Of 1-D Steady-State Heat-Flow Equation,
2016
University of Kentucky
Geotherms From The Temperature-Depth–Constrained Solutions Of 1-D Steady-State Heat-Flow Equation, Dhananjay Ravat, P. Morgan, A. R. Lowry
Earth and Environmental Sciences Faculty Publications
We use the Curie depth derived from spectral analysis of near-surface magnetic anomaly data to constrain the solution of a one-dimensional (1-D) steady-state heat-flow equation. The method, in addition to anchoring the geotherm at deep levels in the crust, yields the ratio of radiogenic heat pro- duction to thermal conductivity. We evaluate the utility of this constraint in two granitic regions in the United States where radiogenic heat production, thermal conductivity, and heat flow are well determined. We also examine the results of this method in the context of previous research in the central Red Sea and coastal Saudi Arabia. …
Spatiotemporal Slip Rate Variations Along Surprise Valley Fault In Relation To Pleistocene Pluvial Lakes,
2016
Central Washington University
Spatiotemporal Slip Rate Variations Along Surprise Valley Fault In Relation To Pleistocene Pluvial Lakes, Brian N. Marion
All Master's Theses
Using mapped paleoshoreline features with high-resolution topographic data and obtained radiocarbon dates on paleoshoreline tufas, I documented precise fault offsets of dated features over the last 25 ka along the Surprise Valley Fault (SVF). Fault offset measured in three lake sections within Surprise Valley ranged from 3.6 m in the southern section to 14.4 m in the central section. The offset paleoshorelines are dated to the late Pleistocene (<22 >ka) and were formed during the latest impoundment of pluvial Lake Surprise since the last glacial maximum. Slip rates vary along strike, assuming a fault dip of 68° with 0.25 ± …
Fluid Release During Eclogite Formation, North Qaidam Terrane, Western China,
2016
Central Washington University
Fluid Release During Eclogite Formation, North Qaidam Terrane, Western China, Jake M. Meyer
All Master's Theses
Ultrahigh-pressure (UHP, depths ≳100 km) eclogite samples from the Dulan area of the North Qaidam Terrane, western China, preserve evidence of fluid release along a prograde pressure-temperature (P-T) path. Eclogite sample D126A, Grt + Omp + Qtz + Zo + Amp + Phe + minor Rt + Hem, contains garnet porphyroblasts that preserve strong Ca zoning, recording higher core values (Grs34), lower inner mantle values (Grs25), increasing outer mantle values (Grs28), and lower rim values (Grs26). Isochemical phase diagrams (pseudosections), assuming H2O saturation, produce a P-T path constrained by multiple …
Investigating Taphonomic Changes Of Deposits And Modeling Of The 2010 Earthquake And Tsunami In South-Central Chile,
2016
Central Washington University
Investigating Taphonomic Changes Of Deposits And Modeling Of The 2010 Earthquake And Tsunami In South-Central Chile, Alexandra Carranco Ruiz
All Master's Theses
South-central Chile has an extensive written catalog of historic earthquakes and tsunamis, but such records can be subject to inconsistencies. Dated tsunami deposits are more objective data that provide hard evidence of past tsunamis. The inland extent of deposits from past tsunamis (paleodeposits) can be used in tsunami modeling to reveal characteristics of the source earthquake, but these deposits may have undergone taphonomic processes since initial deposition. Therefore, to determine how tsunami deposits change during burial and preservation and the potential limitations of using paleodeposits in modeling, I investigated the modern 2010 Mw 8.8 Maule earthquake and tsunami as …
Documenting Mantle And Crustal Contributions To Flood Basalt Magmatism Via Computational Modeling Of The Steens Basalt, Southeast Oregon,
2016
Central Washington University
Documenting Mantle And Crustal Contributions To Flood Basalt Magmatism Via Computational Modeling Of The Steens Basalt, Southeast Oregon, Sylvana J. Bendaña
All Master's Theses
Flood basalts are enormous volcanic events with volumes of volcanic cover and intrusive equivalents that are affected by and significantly affect the crust. Steens Basalt represents 31,800 km3 of flood basalt lavas that erupted in eastern Oregon ~16.8 Ma in less than 300,000 years. Analytical data of flows from a 1 km vertical exposure at Steens Mtn. documents time-transgressive changes in composition of two geochemically distinct units: (1) lower Steens, MgO-rich lavas with lower incompatible trace element concentrations and 87Sr/86Sr, and (2) upper Steens, MgO-poor, with higher incompatible trace element concentrations and 87Sr/86Sr. …
Evolution Of A Flood Basalt Crustal Magmatic System: In Situ Mineral Data And Computational Modeling Of The Steens Basalt,
2016
Central Washington University
Evolution Of A Flood Basalt Crustal Magmatic System: In Situ Mineral Data And Computational Modeling Of The Steens Basalt, Megan Graubard
All Master's Theses
Flood basalts are gigantic basaltic eruptions that modify the mass of the crust via intrusion of mantle-derived magma, and change its composition through interaction between magma and crust. The Steens Basalt, located in southeast Oregon, erupted approximately 16.8 million years ago, and is the oldest member of the Columbia River Basalt Group, the youngest and best-exposed flood basalt province on Earth. The Steens Basalt has an eruption volume of approximately 31,800 km3 and the duration of eruption is estimated to be between ~50,000 and 300,000 years. Major- and trace element whole rock data from 111 stratigraphically controlled samples from …
Black Carbon Concentrations From A Tibetan Plateau Ice Core Spanning 1843–1982: Recent Increases Due To Emissions And Glacier Melt,
2016
Central Washington University
Black Carbon Concentrations From A Tibetan Plateau Ice Core Spanning 1843–1982: Recent Increases Due To Emissions And Glacier Melt, Susan Kaspari, Matthew Jenkins, Shi-Chang Kang, Bjorn Grigholm
Geological Sciences Faculty Scholarship
Black carbon (BC) deposited on snow and glacier surfaces can reduce albedo and lead to accelerated melt. An ice core recovered from Guoqu glacier on Mt. Geladaindong and analyzed using a Single Particle Soot Photometer provides the first long-term 5 (1843–1982) record of BC concentrations from the Central Tibetan Plateau. The highest concentrations are observed from 1975–1982, which corresponds to a 2.0-fold and 2.4-fold increase in average and median values, respectively, relative to 1843–1940. BC concentrations post-1940 are also elevated relative to the earlier portion of the record. Causes for the higher BC concentrations include increased regional BC emissions and …
Origin Of Late Holocene Strandplains In The Southern Exuma Islands, Bahamas: Progradation, Ephemeral Highstands, And Storminess,
2016
Florida Gulf Coast University
Origin Of Late Holocene Strandplains In The Southern Exuma Islands, Bahamas: Progradation, Ephemeral Highstands, And Storminess, Michael Savarese, H. Allen Curran
Geosciences: Faculty Publications
Reprinted from: Bosiljka Glumac & Michael Savarese (eds.), Proceedings of the16th Symposium on the Geology of the Bahamas and Other Carbonate Regions:San Salvador, Gerace Research Center
Subaerial Seeps On Holocene Carbonate Eolian Strata From Cat Island, Bahamas,
2016
Smith College
Subaerial Seeps On Holocene Carbonate Eolian Strata From Cat Island, Bahamas, Bosiljka Glumac, H. Allen Curran, Sarah Brisson
Geosciences: Faculty Publications
Reprinted from: Bosiljka Glumac & Michael Savarese (eds.),Proceedings of the 16th Symposium of the Geology of the Bahamas and Other Carbonate Regions: San Salvador, Gerace Research Center
Glacial Deposits, Vol. 41, 2016,
2016
Illinois State University
Glacial Deposits, Vol. 41, 2016, Department Of Geography-Geology
Glacial Deposits
Newsletter of the Department of Geography-Geology
Response Of Antarctic Cryoconite Microbial Communities To Light,
2016
Cardiff University
Response Of Antarctic Cryoconite Microbial Communities To Light, Elizabeth A. Bagshaw, Jemma L. Wadham, Martyn Tranter, Rupert Perkins, Alistair Morgan, Christopher J. Williamson, Andrew G. Fountain, Sean Fitzsimons, Ashley Dubnick
Geology Faculty Publications and Presentations
Microbial communities on polar glacier surfaces are found dispersed on the ice surface, or concentrated in cryoconite holes and cryolakes, which are accumulations of debris covered by a layer of ice for some or all of the year. The ice lid limits the penetration of photosynthetically available radiation (PAR) to the sediment layer, since the ice attenuates up to 99% of incoming radiation. This suite of field and laboratory experiments demonstrates that PAR is an important control on primary production in cryoconite and cryolake ecosystems. Increased light intensity increased efficiency of primary production in controlled laboratory incubations of debris from …
Stratigraphy And Extent Of The Pearl-Ashmore Aquifer, Mchenry County, Il, Usa,
2016
Illinois State University
Stratigraphy And Extent Of The Pearl-Ashmore Aquifer, Mchenry County, Il, Usa, Drew C. Carlock, Jason F. Thomason, David H. Malone, Eric W. Peterson
Faculty Publications - Geography, Geology, and the Environment
Quaternary glacial till, outwash, lake sediments, and loess compose the surficial deposits of McHenry County, Illinois. Much of the landscape of McHenry County were formed by at least three separate advances of the Harvard Sublobe of the Wisconsin Episode Lake Michigan Lobe, which was part of the Laurentide Ice Sheet. This project focuses on the delineation of the stratigraphy and extent of the Pearl-Ashmore Aquifer. The Pearl-Ashmore Aquifer is the combination of the proglacial outwash of the Wisconsin Episode Ashmore Tongue of the Henry Formation and the youngest outwash associated with the Illinois Episode, which is the Pearl Formation. A …
Land Use Regulation And Access To Amenities: Exploring Spatial Equity Using Gis,
2016
University of North Alabama
Land Use Regulation And Access To Amenities: Exploring Spatial Equity Using Gis, Robert B. Thompson
Theses
No abstract provided.
Late Glacial And Holocene History Of The Penobscot River In The Penobscot Lowland, Maine,
2016
University of Maine
Late Glacial And Holocene History Of The Penobscot River In The Penobscot Lowland, Maine, Roger Leb. Hooke, Paul R. Hanson, Danile F. Belknap, Alice R. Kelley
Conservation and Survey Division: Faculty and Staff Publications
When the Laurentide ice sheet retreated rapidly (~150 m/a) across the Penobscot Lowland between ~16 and ~15 ka, the area was isostatically depressed and became inundated by the sea. Silt and clay were deposited, but no significant moraines or deltas were formed. The Penobscot River was reborn at ~14 ka when ice retreated onto land in the upper reaches of the river’s East Branch. As isostatic rebound exceeded sea level rise from melting ice, the river extended itself southward. Between ~13.4 and 12.8 ka, it established a course across marine clay and underlying glacial till in the Lowland. Its gradient …
Coherent Late-Holocene Climate-Driven
Shifts In The Structure Of Three Rocky
Mountain Lakes,
2016
Indiana State University
Coherent Late-Holocene Climate-Driven Shifts In The Structure Of Three Rocky Mountain Lakes, Jeffrey R. Stone, Jasmine E. Saros, Gregory T. Pederson
United States Geological Survey: Staff Publications
Large-scale atmospheric pressure centers, such as the Aleutian and Icelandic Low, have a demonstrated relationship with physical lake characteristics in contemporary monitoring studies, but the responses to these phenomena are rarely observed in lake records. We observe coherent changes in the stratification patterns of three deep (>30 m) lakes inferred from fossil diatom assemblages as a response to shifts in the location and intensity of the Aleutian Low and compare these changes with similar long-term changes observed in the 18O record from the Yukon. Specifically, these records indicate that between 3.2 and 1.4 ka, the Aleutian Low shifted …
Using Satellite Vegetation And Compound Topographic Indices To Maphighly Erodible Cropland Buffers For Cellulosic Biofuel Cropdevelopments In Eastern Nebraska, Usa,
2016
ASRC Research & Technology Solutions
Using Satellite Vegetation And Compound Topographic Indices To Maphighly Erodible Cropland Buffers For Cellulosic Biofuel Cropdevelopments In Eastern Nebraska, Usa, Yingxin Gu, Bruce K. Wylie
United States Geological Survey: Staff Publications
Cultivating annual row crops in high topographic relief waterway buffers has negative environmental effects and can be environmentally unsustainable. Growing perennial grasses such as switchgrass(Panicum virgatum L.) for biomass (e.g., cellulosic biofuel feedstocks) instead of annual row crops in these high relief waterway buffers can improve local environmental conditions (e.g., reduce soil erosion and improve water quality through lower use of fertilizers and pesticides) and ecosystem services (e.g.,minimize drought and flood impacts on production; improve wildlife habitat, plant vigor, and nitro-gen retention due to post-senescence harvest for cellulosic biofuels; and serve as carbon sinks). The main objectives of this …
Evaluating Methods To Establish Habitat Suitability Criteria: A Case
Study In The Upper Delaware River Basin, Usa,
2016
USGS Leetown Science Center
Evaluating Methods To Establish Habitat Suitability Criteria: A Case Study In The Upper Delaware River Basin, Usa, H. S. Galbraith, C. J. Blakeslee, J. C. Cole, C. A. Talbert, K. O. Maloney
United States Geological Survey: Staff Publications
Defining habitat suitability criteria (HSC) of aquatic biota can be a key component to environmental flow science. HSC can be developed through numerous methods; however, few studies have evaluated the consistency of HSC developed by different methodologies. We directly compared HSC for depth and velocity developed by the Delphi method (expert opinion) and by two primary literature meta-analyses (literature- derived range and interquartile range) to assess whether these independent methods produce analogous criteria for multiple species (rainbow trout, brown trout, American shad, and shallow fast guild) and life stages. We further evaluated how these two independently developed HSC affect calculations …
