Open Access. Powered by Scholars. Published by Universities.®

Geology Commons™

Open Access. Powered by Scholars. Published by Universities.®

29,998 Full-Text Articles 16,197 Authors 6,782,393 Downloads 178 Institutions

All Articles in Geology

Faceted Search

29,998 full-text articles. Page 1229 of 1250.

Palynomorph And Palynofacies Assemblages Of Neutral-Alkaline And Acid Lakes South Of Norseman, Southern Western Australia, Lutfia Grabel 2012 Missouri University of Science and Technology

Palynomorph And Palynofacies Assemblages Of Neutral-Alkaline And Acid Lakes South Of Norseman, Southern Western Australia, Lutfia Grabel

Masters Theses

"The Yilgarn Craton in Western Australia hosts hundreds of shallow ephemeral hypersaline lakes, the majority of which have acid to neutral pH values. As part of a multidisciplinary study of the evolution of hypersalinity and acidity in the region, three drill cores were studied for their palynofacies and palynomorph contents in order to characterize palynofloral response to environmental changes. Drill cores from two acid lakes, Prado Lake (PL1-09 and PL2-09) and Twin Lake West (TLW1-09), and the neutral-alkaline Gastropod Lake (GLE1-09) south of Norseman recovered Miocene to Holocene sediments of the Revenge and Polar Bear formations. Transmitted light microscopy was …


Using Lidar As A Monitoring Device To Calculate Volume Of Rockfall Over Time, Travis James Kassebaum 2012 Missouri University of Science and Technology

Using Lidar As A Monitoring Device To Calculate Volume Of Rockfall Over Time, Travis James Kassebaum

Masters Theses

"There are many natural hazards which threaten the stability of highway infrastructure and the safety of motoring public. Rockfall and unstable slopes are one of the major concerns. This thesis describes a method which safely and accurately evaluates rockfall on rock outcrops through the use of Light Detection and Ranging (LiDAR) data. LiDAR is an imaging technology which can be used to measure and evaluate possible rock outcrop hazards such as: rockfall, rock-avalanches, debris flows, and landslides. LiDAR produces a three dimensional point cloud of millions of points which gives spatial data on the scanned object, accurate to millimeters, in …


Depositional And Tectonic Controls On Architecture Of The Carbonate Platform Of Upper Paleocene Khalifah Formation, Sirte Basin, Central Libya, Salah Abdurzak Shaniba 2012 Missouri University of Science and Technology

Depositional And Tectonic Controls On Architecture Of The Carbonate Platform Of Upper Paleocene Khalifah Formation, Sirte Basin, Central Libya, Salah Abdurzak Shaniba

Masters Theses

"The Paleocene strata in Sirte Basin, Libya, contain major oil and gas accumulations in a variety of lithofacies of reef and bioherm carbonate depositional environments. The Upper Paleocene Khalifah Formation, which is one of the main reservoirs containing about 30% of the oil reserves of the Sirte Basin, is composed of shallowing-upward and carbonate platform deposits and is capped by open marine shale deposits formed during a marine transgression. Well and seismic data are used to interpret the depositional environments and identify upward shallowing and deepening trends in the formation. In the study area, Mabruk oil field in northwestern Sirte …


Landsat Remote Sensing Data As An Alternative Approach For Geological Mapping In Tanzania: A Case Study In The Rungwe Volcanic Province, South-Western Tanzania, E. E. Mshiu 2011 Geology Department, University of Dar es Salaam, P. O. Box 35052, Dar es Salaam

Landsat Remote Sensing Data As An Alternative Approach For Geological Mapping In Tanzania: A Case Study In The Rungwe Volcanic Province, South-Western Tanzania, E. E. Mshiu

Tanzania Journal of Science

Rungwe Volcanic Province (RVP) is mostly covered by extrusive rocks that overlain the Precambrian basement. The use of Landsat data in this area has revealed the need of effective use of these data in geological mapping programs in Tanzania. Landsat band ratios 5/1, 3/7, 5/7 and 5/4 as well as R: G: B composite images 7:4:1, 7:5:4, 1/3:5/7:3/5 and 4/5:6/7:4/6 played an important role in identifying different rock types in the study area. Ratio images managed clearly to distinguish between mafic and felsic rocks whereby two lithological blocks were identified, Block 1 covers a combination of intrusive and metamorphic rocks …


Petrography And Geochemistry Of Mafic Granulites Of The Ubendian Belt: Contribution To Insights Into The Lower Continental Crust Of The Paleoproterozoic, N. Boniface 2011 University of Dar es Salaam, College of Natural and Applied Sciences, Department of Geology, P. O. Box 35052, Dar es Salaam, Tanzania

Petrography And Geochemistry Of Mafic Granulites Of The Ubendian Belt: Contribution To Insights Into The Lower Continental Crust Of The Paleoproterozoic, N. Boniface

Tanzania Journal of Science

Mafic granulites of the Ubendian Belt have geochemical signature, trace and REE patterns, similar to that of the lower continental crustal rocks. A SHRIMP U-Pb single zircon date at 1977±40 Ma indicates that these rocks belong to the Paleoproterozoic Ubendian orogenic cycle, which was followed by the Mesoproterozoic tectonic disturbance that contributed to their exhumation. Orthopyroxene, clinopyroxene, garnet, hornblende, plagioclase and quartz is a frequent mineral assemblage for the mafic granulites of the Ubendian Belt, and garnet frequently form corona between plagioclase and clinopyroxene. Geothermobarometric calculations have revealed the equilibration of these rocks at a temperature range between 650 and …


Contact Metamorphism In The Supracrustal Rocks Of The Sukumaland Greenstone Belt In The North West Tanzania, N. Boniface 2011 University of Dar es Salaam, College of Natural and Applied Sciences, Department of Geology, P. O. Box 35052, Dar es Salaam, Tanzania

Contact Metamorphism In The Supracrustal Rocks Of The Sukumaland Greenstone Belt In The North West Tanzania, N. Boniface

Tanzania Journal of Science

Biotite-granite intrusions in meta-ironstones at Geita Hills and the Bukoli alkali-granite intrusion in metabasites at Mawemeru area produced heat that baked the respective country rocks through epidote-amphibolite- to amphibolite-facies. Critical and informative mineral assemblages in the metairostones of Geita Hills are garnet-grunerite-epidote-quartz and garnetferrogedrite- biotite-quartz and in the metabasites of Mawemeru is ferrotschermakite-(Naplagioclase)- quartz. Peak temperatures ranging between 438°C and 544°C were calculated from the above mineral assemblages and a pressure not exceeding 3 kbar was inferred to from the composition of magnesium-iron amphiboles (grunerite with XFe ratio of 0.83, i.e. Gru83). Hornfels textures in the metaironstones are suggested by …


Evaluation Of Single-Step Steam Pyrolysis-Activated Carbons From Lesotho Agro-Forestry Residues, I. Hapazari, V. Ntuli, W. Parawira 2011 Department of Chemistry and Chemical Technology, National University of Lesotho, P.O. Roma, 180, Lesotho

Evaluation Of Single-Step Steam Pyrolysis-Activated Carbons From Lesotho Agro-Forestry Residues, I. Hapazari, V. Ntuli, W. Parawira

Tanzania Journal of Science

Activated carbon has been widely used worldwide as an effective filtration or adsorption material for removing biological and chemical contaminants from drinking water. The potential of producing activated carbon (AC) from local agroforestry residues by single-step steam pyrolysis processes was investigated. The research aims to promote innovative use of local raw materials and relatively low-cost techniques in production of activated carbon. Four varieties of activated carbons from four different agroforestry residues, pine (Pinus contorta) cones (PC), Abies (Abies cilicica) seeds (AS), maple (Acer ginnala) seeds (MS) and peach (Prunus persica) stones (PS), were prepared and evaluated. The ACs were evaluated …


Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen 2011 Central Washington University

Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen

All Faculty Scholarship for the College of the Sciences

Differences in the timing of glacial advances, which are commonly attributed to climatic changes, can be due to variations in valley topography. Cosmogenic 10Be dates from 24 glacial moraine boulders in 5 valleys define two age populations, late-glacial and early Holocene. Moraine ages correlate with paleoglacier valley hypsometries. Moraines in valleys with lower maximum altitudes date to the lateglacial, whereas those in valleys with higher maximum altitudes are early Holocene. Two valleys with similar equilibrium-line altitudes (ELAs), but contrasting ages, are < 5 km apart and share the same aspect, such that spatial differences in climate can be excluded. A glacial mass-balance cellular automata model of these two neighboring valleys predicts that change from a cooler-drier to warmer-wetter climate (as at the Holocene onset) would lead to the glacier in the higher altitude catchment advancing, while the lower one retreats or disappears, even though the ELA only shifted by ~120 m.


Collisional Reactivation Of Rift Margin Fracture Zones, Taiwan And The Taconic Allochthon, David C. Mirakian 2011 University of Connecticut

Collisional Reactivation Of Rift Margin Fracture Zones, Taiwan And The Taconic Allochthon, David C. Mirakian

Master's Theses

Chapter I. Transverse Topographic Development due to the Reactivation of a Partially-Subducted Fracture Zone: The Southwest Hsüehshan Range, Central Taiwan

Abstract — The southwest flank of the Hsüehshan Range is defined by a topographic break which cuts across regionally mapped structures in central Taiwan. The mountain front trends ~345°, slightly oblique to the Sanyi-Puli seismic zone which has been previously interpreted as a reactivated continental margin fracture zone. Structural data collected along the length of the topographic break reveal two populations of cross-cutting faults with distinct fault-zone materials and a series of southwest-plunging folds. Paleostress axes were reconstructed using the …


Mineralogy And Geochemistry Of Anorogenic Granitic Miarolitic Pegmatites Associated With The White Mountain Intrusive Suite, New Hampshire, Kristen F. Camp 2011 University of New Orleans

Mineralogy And Geochemistry Of Anorogenic Granitic Miarolitic Pegmatites Associated With The White Mountain Intrusive Suite, New Hampshire, Kristen F. Camp

LSU New Orleans Theses and Dissertations

Subvolcanically emplaced granitic, miarolitic pegmatites associated with the White Mountain Igneous Province (WMIP), New Hampshire, were sampled and analyzed using modern analytical techniques including X-ray fluorescence, electron microprobe, scanning electron microscopy, and direct-coupled plasma spectrophotometry. Analytical results suggest that all the sampled miarolitic pegmatites from this study are petrogenetically related to the same intrusive suite, the WMIP. Based on the geochemical data, all the samples formed in an anorogenic tectonic setting and are rift-related. They are classified as NYF-type and plot in the “within plate granite” field on tectonic discrimination diagrams. The majority of the samples are peraluminous, A1 …


Understanding Uplift Of The Ethiopian Plateau From Longitudinal Profile Analysis Of The Blue Nile Drainage System, Prabhat Chandra Neupane 2011 University of New Orleans

Understanding Uplift Of The Ethiopian Plateau From Longitudinal Profile Analysis Of The Blue Nile Drainage System, Prabhat Chandra Neupane

LSU New Orleans Theses and Dissertations

The Ethiopian Plateau is one of the few tectonically-active regions on Earth that is situated in continental rift zones. About 1.6 km deep gorge of the Nile was carved by the Blue Nile River on the Ethiopian Plateau, as the plateau has been experiencing continuous uplift and exhumation in the Cenozoic. Here, we used quantitative analysis of longitudinal rive-profile forms and parameters (knickpoint and normalized steepness-index ksn) of the Blue Nile tributaries to tease out regional tectonic signals.

244 knickpoints were examined in the tributaries, majority (>80%) of which are unassociated with lithology or geological structures. Knickpoint …


Paleomagnetic Constraints On Deformation Of Superfast-Spread Oceanic Crust Exposed At Pito Deep Rift, Andrew J. Horst, R. J. Varga, J. S. Gee, J. A. Karson 2011 Marshall University

Paleomagnetic Constraints On Deformation Of Superfast-Spread Oceanic Crust Exposed At Pito Deep Rift, Andrew J. Horst, R. J. Varga, J. S. Gee, J. A. Karson

Natural Resources and Earth Sciences Faculty Research

The uppermost oceanic crust produced at the superfast spreading (∼142 km Ma −1, full‐spreading rate) southern East Pacific Rise (EPR) during the Gauss Chron is exposed in a tectonic window along the northeastern wall of the Pito Deep Rift. Paleomagnetic analysis of fully oriented dike (62) and gabbro (5) samples from two adjacent study areas yield bootstrapped mean remanence directions of 38.9° ± 8.1°, −16.7° ± 15.6°, n = 23 (Area A) and 30.4° ± 8.0°, −25.1° ± 12.9°, n = 44 (Area B), both are significantly distinct from the Geocentric Axial Dipole expected direction at 23° S. Regional tectonics …


An Integrated Geophysical And Geologic Study Of The Paleogene-Age Volcanic Body And Possible Landslide Deposit On The South Slope Of The Traverse Mountains, Utah, John C. Hoopes 2011 Brigham Young University - Provo

An Integrated Geophysical And Geologic Study Of The Paleogene-Age Volcanic Body And Possible Landslide Deposit On The South Slope Of The Traverse Mountains, Utah, John C. Hoopes

Theses and Dissertations

Development of homes, roads, and commercial buildings in northern Utah has grown significantly during the last several decades. Construction has expanded from the valley floor to higher elevations of benches, foothills, and other elevated regions of the Wasatch Mountain Front. Construction in the higher elevation areas are a concern due to potential for landslides, both new and reactivated. Landslides have been identified in this region and are dated as Pleistocene to historical in age. A possible landslide of about 0.5 km2 on the south slope of Traverse Mountain has been mapped by the Utah Geological Survey in 2005. Its surface …


Quantification Of Glacier Melt Volume In The Indus River Watershed, Maria Nicole Asay 2011 Brigham Young University - Provo

Quantification Of Glacier Melt Volume In The Indus River Watershed, Maria Nicole Asay

Theses and Dissertations

Quantifying the contribution of glaciers to water resources is particularly important in locations where glaciers may provide a large percentage of total river discharge. In some remote locations, direct field measurements of melt rates are difficult to acquire, so alternate approaches are needed. Positive degree-day modeling (PDD) of glacier melt is a valuable tool to making first order approximations of the volume of melt coming from glaciers. In this study, a PDD-melt model is applied to glaciers in the Indus River watershed located in Afghanistan, China, India, and Pakistan. Here, millions of people rely on the water from the Indus …


Vulnerability Of High Latitude Soil Organic Carbon In North America To Disturbance, Guido Grosse, Jennifer Harden, Merritt Turetsky, David A. McGuire, Philip Camill, Charles Tarnocai, Steve Frolking, Edward A.G. Schuur, Torre Jorgenson, Sergei Marchenko, Vladimir Romanovsky, Kimberly P. Wickland, Nancy H. F. French, Mark Waldrop, Laura Bourgeau-Chavez, Robert G. Striegl 2011 University of Alaska, Fairbanks

Vulnerability Of High Latitude Soil Organic Carbon In North America To Disturbance, Guido Grosse, Jennifer Harden, Merritt Turetsky, David A. Mcguire, Philip Camill, Charles Tarnocai, Steve Frolking, Edward A.G. Schuur, Torre Jorgenson, Sergei Marchenko, Vladimir Romanovsky, Kimberly P. Wickland, Nancy H. F. French, Mark Waldrop, Laura Bourgeau-Chavez, Robert G. Striegl

Michigan Tech Research Institute Publications

This synthesis addresses the vulnerability of the North American high-latitude soil organic carbon (SOC) pool to climate change. Disturbances caused by climate warming in arctic, subarctic, and boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts. We divide the current northern high-latitude SOC pools into (1) near-surface soils where SOC is affected by seasonal freeze-thaw processes and changes in moisture status, and (2) deeper permafrost and peatland strata down to several tens of meters depth where SOC is usually not affected by short-term changes. We address key factors (permafrost, vegetation, hydrology, paleoenvironmental history) …


Land Systems Of The Kimberley Region, Western Australia, A L. Payne, N Schoknecht 2011 Department of Primary Industries and Regional Development, Western Australia

Land Systems Of The Kimberley Region, Western Australia, A L. Payne, N Schoknecht

Technical Bulletins

The Land Systems of the Kimberley Region Report describes and maps the landscapes, soils and vegetation of the Kimberley region. This report is a consolidation of surveys carried out by different organisations, across different areas of the Kimberley, since the 1940s. The Kimberley region, as defined in this bulletin, covers 330 070km². The report categorises the Kimberley region into 111 land systems. Under each land system, the report identifies the vulnerabilities of those areas, and provides recommendations on how to achieve sustainable use. The report also publishes pasture types for the entire region and the grazing potential for each pasture, …


The Interrelationship Between The Bio- And Sequence Stratigraphy Of The Middle Cambrian Spence Shale Of Northern Utah And Southern Idaho, Eva Lyon 2011 Utah State University

The Interrelationship Between The Bio- And Sequence Stratigraphy Of The Middle Cambrian Spence Shale Of Northern Utah And Southern Idaho, Eva Lyon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was undertaken with the objective of discerning the relationship between sea level change and changes in the fauna of the Spence Shale. A combination of field and lab work was employed to undertake this research. The Spence Shale is rich in fossils from the earliest period of visible life on this planet. It provides a unique window onto the evolution of life and changes in the Earth at this time. It is important to study this relationship between sea level and life changes as these conditions are constantly changing, particularly in this day and age. A better understanding …


Determining Co2 Storage Potential: Characterization Of Seal Integrity And Reservoir Failure In Exposed Analogs, Daniel Corey Barton 2011 Utah State University

Determining Co2 Storage Potential: Characterization Of Seal Integrity And Reservoir Failure In Exposed Analogs, Daniel Corey Barton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sequestration of carbon dioxide (CO2) into subsurface porous sandstone is proposed as a method for reducing accumulation of anthropogenic emissions of CO2 into the atmosphere. Natural exposures of reservoir and top-seal pairs in central and southeastern Utah are identified as analogs to proposed CO2 injection targets. Reservoir and top-seal pairs in natural analog exposures are analyzed in tandem to evaluate evidence for paleo-migration of fluids and/or hydrocarbons from the reservoir through the top seal. The San Rafael Swell and Monument Uplift exhibit similar structure and exposures of Jurassic units yet differ in amount and type of …


Assessing Flood Inundation Mapping With The Use Of A Dem And Gis Along The Missouri River At Sioux City, Iowa, Kathryn A. Pfaffle 2011 University of Nebraska-Lincoln

Assessing Flood Inundation Mapping With The Use Of A Dem And Gis Along The Missouri River At Sioux City, Iowa, Kathryn A. Pfaffle

Department of Environmental Studies: Undergraduate Student Theses

There are various methods that are used to predict flood inundation. The U.S. Army Corps of Engineers provided inundation maps for the 2011 Missouri River flood event that did not utilized aerial photo imagery. This study assesses the suitability of using a digital elevation model (DEM) in combination with aerial photo imagery within a geographic information system to predict flood inundation mapping along the Missouri River in Sioux City, Iowa. GPS data was collected during the height of this flood event in order to validate the positional accuracy of the DEM. Using the GPS receiver’s accuracy standards to determine the …


Temporal And Spatial Analysis Of Stream And Groundwater Interactions, Ryan Eugene Warden 2011 Boise State University

Temporal And Spatial Analysis Of Stream And Groundwater Interactions, Ryan Eugene Warden

Boise State University Theses and Dissertations

Water chemistry and ecology of streams are impacted by the amount of water that exchanges between the surface water system and the adjacent saturated area, called the hyporheic zone, a dynamic area of stream channel sediments, which undergoes down-welling or up-welling of stream water. The rate and volume of water exchange between the surface water and the hyporheic zone are primary controls on stream ecology, but are challenging to assess. A common approach is to model the exchange rate with a one-dimensional advection-dispersion equation that includes solute exchange with transient storage zones, which is referred to as a transient storage …


Digital Commons powered by bepress