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

Digital Commons Network™

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

Geology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 26851 - 26880 of 30009

Full-Text Articles in Entire DC Network

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- Republican River Valley And Dissected Plains, D. C. Gosselin, J. Headrick, X-H. Chen, S. E. Summerside Jan 1996

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- Republican River Valley And Dissected Plains, D. C. Gosselin, J. Headrick, X-H. Chen, S. E. Summerside

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- East Central Dissected Plains, D. C. Gosselin, J. Headrick, X-H. Chen, S. E. Summerside Jan 1996

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- East Central Dissected Plains, D. C. Gosselin, J. Headrick, X-H. Chen, S. E. Summerside

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Domestic Well-Water Quality In Rural Nebraska, D. C. Gosselin, J. Headrick, X. H. Chen, S. Summerside, R. Tremblay, K. Bottger Jan 1996

Domestic Well-Water Quality In Rural Nebraska, D. C. Gosselin, J. Headrick, X. H. Chen, S. Summerside, R. Tremblay, K. Bottger

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Data On Mineral Production In Nebraska, R. R. Burchett, D. Mohlman Jan 1996

Data On Mineral Production In Nebraska, R. R. Burchett, D. Mohlman

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


The Effects Of Mass Extinction On Escalation Of The Naticid Gastropod Predator-Prey System At The Eocene-Oligocene, Vicky D. Melland Jan 1996

The Effects Of Mass Extinction On Escalation Of The Naticid Gastropod Predator-Prey System At The Eocene-Oligocene, Vicky D. Melland

Theses and Dissertations

In 1987, Vermeij proposed the hypothesis of escalation, which states that biological hazards, such as predation, have increased through the Phanerozoic. This hypothesis has been extremely controversial due to the fact that it assumes that biotic factors, such as predation, have had an important role in evolution. Several studies have focused on the validity of the hypothesis of escalation. Kelley and Hansen (1996) offered a modified exposition of the escalation hypothesis. The Kelley-Hansen hypothesis states that escalation cycles are punctuated by periods of mass extinction. The periods of mass extinction would preferentially eliminate the highly escalated prey and, therefore, a …


Hydrogeology And Recharge Of The Split Rock Creek Aquifer, Southeastern South Dakota, Stan F. Pence Jan 1996

Hydrogeology And Recharge Of The Split Rock Creek Aquifer, Southeastern South Dakota, Stan F. Pence

Theses and Dissertations

The rapid growth of the city of Sioux Falls, South Dakota, has created a great demand for additional sources of ground water. Due to limited information on the buried, confined Split Rock Creek aquifer near Sioux Falls, a detailed hydrogeologic assessment of the aquifer was conducted to determine the mechanism of recharge to the aquifer.

A four-fold plan was earned out to gather the necessary data. . This plan involved determining the general hydrostratigraphy of the study area by reviewing available data and by drilling test holes where data were limited, collecting water-level data over an extended period, collecting water …


The Depositional Environment Of The Kisbey Sandstone From The Madison Group (Mississippian), North-Central North Dakota, Gregory D. Waltz Jan 1996

The Depositional Environment Of The Kisbey Sandstone From The Madison Group (Mississippian), North-Central North Dakota, Gregory D. Waltz

Theses and Dissertations

The Kisbey Sandstone, also known as the K-2 marker, was studied to understand its depositional environment. It occurs within the Madison Group (Mississippian) of North Dakota. The Madison Group is a regressive, near-shore sequence. In descending order, this Group comprises the Charles, Mission Canyon, and Lodgepole Formations. The K-2 marker appears as well-log defined unit between the Charles and Mission Canyon Formations. Seven counties comprise the 7100 square mile study area. They include Rolette, Bottineau, Renville, McHenry, Ward, Burke, Mountrail Counties, and the southern most adjacent townships in Canada.

For this study, 1677 well-logs were examined. These data were analyzed …


Hydrologic Factors Affecting The Discharge Of Ground Water In The Red River Of The North Basin, Northeastern North Dakota, Michael Lee Strobel Jan 1996

Hydrologic Factors Affecting The Discharge Of Ground Water In The Red River Of The North Basin, Northeastern North Dakota, Michael Lee Strobel

Theses and Dissertations

Ground-water discharge from bedrock aquifers contributes significant amounts of salinity to the Red River of the North. The area of major discharge is represented on the land surface by saline soils, wetlands, and flowing wells. As tributaries flow through these areas, the dissolved-solids concentrations in the streams increase. This salinity is then transported to the Red River of the North and northward to Canada. The bedrock units that supply the saline water are mainly the Dakota Group. Overlying the bedrock are sediments from numerous glacial advances and lacustrine sediments from glacial Lake Agassiz. These units form confining layers over the …


The Effects Of Non-Linear Bromide Adsorption On Apparent Macrodispersivity, Eron J. Dodak Jan 1996

The Effects Of Non-Linear Bromide Adsorption On Apparent Macrodispersivity, Eron J. Dodak

Theses and Dissertations

Macrodispersivity estimates are crucial in predicting the subsurface transport of contaminants. These predictions have become increasingly important as the number of contaminated sites continues to increase. In addition, the longevity of many contaminants can affect water quality over extended periods of time.

Anionic tracers such as bromide and chloride are commonly used as groundwater tracers in dispersivity experiments because they are inexpensive, easily detected, and are commonly believed to behave conservatively. It has been found, however, that anionic tracers do not always behave conservatively; sediments with a net positive surface charge can adsorb some-of the tracer.

A weakly non-linear, experimentally …


Hydrogeological Characterization Of The Akzo Salt Company, Williston Facility, Williston, North Dakota, Jane K. Geiger Jan 1996

Hydrogeological Characterization Of The Akzo Salt Company, Williston Facility, Williston, North Dakota, Jane K. Geiger

Theses and Dissertations

Operations at the Akzo Salt Company near Williston, ND, have resulted in saline contamination of the surface and subsurface in the general vicinity of the company property and possibly the surrounding area. The company site lies on the floodplain of Stony Creek and waste salt is buried just north of the plant. The salt dump poses surface and groundwater hazards. A recent flood on the plant site in August of 1993 resulted in groundwater corning into contact with buried salt. Groundwater quality and water level elevation data collected by the North Dakota Health Department, the North Dakota Geological Survey and …


Application Of Multivariate Analysis In The Exploration For Tin In Granites: A Study Of Granites From Northwestern Tanzania Using Discriminant Function And Factor Analysis, J.R. Ikingura Dec 1995

Application Of Multivariate Analysis In The Exploration For Tin In Granites: A Study Of Granites From Northwestern Tanzania Using Discriminant Function And Factor Analysis, J.R. Ikingura

Tanzania Journal of Science

Variations in major and trace element Composition of granites from Karagwe-Ankolean (NE Kibaran) belt in northwestern Tanzania have been investigated by factor analysis and discriminant function statistical methods, The variations are attributed to three main factors. Factor 1 is positively loaded with CaO, MgO, Fe2O3 (Fe total), TiO2, MnO, Ba, Sr, Zr and Y, and negatively loaded with P2O5, SiO2, B and Rb. Factor 2 is positively loaded with Na2O, P2O5 Mno, Sn, Li, Rb and Y, and negatively loaded with TiO2, K2 …


Uplift And Erosion Of The Livingstone Basin Rift Flanks, Malawi (Nyasa) Rift, East Africa: Apatite Fission Track Analysis, Mbede E. I Dec 1995

Uplift And Erosion Of The Livingstone Basin Rift Flanks, Malawi (Nyasa) Rift, East Africa: Apatite Fission Track Analysis, Mbede E. I

Tanzania Journal of Science

Apatite fission track (AFT) dating is a method applied in neotectonic studies of sedimentary basin and in constraining uplift histories of rift flanks. Dating of 20 AFT samples of basement rocks flanking the Livingstone (Karonga/Tukuyu) basin on the northern edge of the Malawi (Nyasa) rift is used to analyse the uplift and erosionofthe basin flanks. Results suggest that in the Livingstone basin, rift-related uplift and erosion of the flanks has modified the topographic patterns. The high elevation of the Livingstone Mountains is related to regionally distributed isostatic rebound, whereas the topography of the hanging wall flank has probably been severely …


Gravity Data Interpretation Of The Usangu Baisin Tanzania, I.M. Marobhe, E.I. Mbede Dec 1995

Gravity Data Interpretation Of The Usangu Baisin Tanzania, I.M. Marobhe, E.I. Mbede

Tanzania Journal of Science

The shape and geometry of Rift of basins is best expressed by looking at the depth to basement maps. It is now an accepted idea that the Rift basins are spoon shaped bounded on one side by a border fault (BF) which is normally the side of maximum sediment deposition. Gravity data from Usangu Basin collected by Amoco in 1985 are here interpreted to decipher the shape and the geometry of the Basin. Results suggest that the Usangu basin shape is similar to the other Rift Basins within the East African Rift System (EARS). The basin, is however, traversed by …


Natural Zeolites For Pollution Control An Overview, M.M. Makweba Dec 1995

Natural Zeolites For Pollution Control An Overview, M.M. Makweba

Tanzania Journal of Science

Natural zeolites are minerals characterized by a framework of alumino-silicate whose structure contains channels occupied by water and exchangeable cations. The common known zeolites which occur in sedimentary rocks of volcanic origin include analcime, clinoptilolite, heulandite laumontite, philipsite, chabazite, erionite and mordenite. The zeolites have been studied in detail on their physical and chemical propertied. The ability of zeolite minerals like clinoptilolite to remove Cs-137 and Sr-90 from radioactive waste waters and to remove ammonium ions from municipal waste waters has been a milestone for zeolites to be applicable in pollution control. In Tanzania, zeolites occurrences have been reported in …


Algal Stromatolites From The Late Permian Lacustrine Sediments Of Tanzania, C.Z. Kaaya Dec 1995

Algal Stromatolites From The Late Permian Lacustrine Sediments Of Tanzania, C.Z. Kaaya

Tanzania Journal of Science

Thin bed of algal stromatolites and oolites occur within a distinct stratigraphic unit (60-120 m thick) in the Late Permian (Karoo) lacustrine sedimetns of the Ruhuhu Basin in SW Tanzania. The stromatolites vary from a few centimeters to 50 cm high and exhibit 4 morphotypes: 1) bulbous or domal 2) columnar. Branching and non-branching varieties are common in the two morphotypes. The other two are : 3) laminated mats and 4) oncolites. All four types may occur in one bed. Filamentous algae were responsible for the building up of the stromatolites in which there was more precipitation of calcite than …


Determination Of Tine In Geological Samples By Energy Dispersive X-Ray Fluorescence With A Secondary Target, J. M. J. Kahatano, M. Mwambeule Dec 1995

Determination Of Tine In Geological Samples By Energy Dispersive X-Ray Fluorescence With A Secondary Target, J. M. J. Kahatano, M. Mwambeule

Tanzania Journal of Science

Tin has been determined in seven international geochemical reference samples with energy-dispersive X-Ray Fluorescence using an X-ray tube with a secondary target, after optimization of the working parameters and instrument settings. The tin values obtained in this work quite satisfactorily lie within ranges reported in the literature or recommended by the suppliers of the reference samples. The method can therefore be applied to supplement other analytical techniques in the elemental analysis of geochemical samples.


Stratigraphy And Tectonic Evolution Of The Palaeoproterozoic Usagaran Belt In South-Eastern Tanzania, A.H. Mruma Dec 1995

Stratigraphy And Tectonic Evolution Of The Palaeoproterozoic Usagaran Belt In South-Eastern Tanzania, A.H. Mruma

Tanzania Journal of Science

The palaeoproterzoic Usagaran Belt is bordered by the Archaean Tanzanian Craton to the NW and the Mozambique Belt to the east. It is made up of the following three stratigraphic units:- (i) The lithodemic sillimanite, kyanite and cordierite gneiss lithodemes and pyroxene-garnet amphibolite lithodemes (ii) The lithostratigraphic Konse Group : greenschist to lower amphibolite facies metasedimentary and metavolcanic formations. (iii) The metavolcanic Ndembera Group; a possible lateral equivalent of the konse. Furthermore, the belt contains a post-tectonic gabbro-granitoid suite. The mutual stratigraphic relationship of the konse and Isimani has been a matter of dispute. However, the field observations described in …


The Mozambique Of Eastern Tanzania: Evidence For Pan-African Reactivation Of Early Proterozoic Usagaran Basement, M.A.H. Maboko Dec 1995

The Mozambique Of Eastern Tanzania: Evidence For Pan-African Reactivation Of Early Proterozoic Usagaran Basement, M.A.H. Maboko

Tanzania Journal of Science

The high grade metamorphic rocks of Eastern Tanzania belong to two distinct tectonothermal belts; the early Proterozoic Usagaran Belt and the late Proterozoic (Pan–African) Mozambique Belt. Rocks of the Usagaran Belt, which locally sow evidence of eclogite facies metamorphism, experienced peak metamorphic conditions at ⁓ 2000 Ma. Tectonic activity in the Usagaran added at ⁓ 1800 Ma with the emplacement of post-organic granites. In contrast, the Mozambique Belt, which is characterized by extensive granulite complexes, experienced peak metamorphic conditions at about 700 Ma. Due to the similarity of both structural trends and metamorphic grade, the boundary between the two belts …


Weathering On The Alkaline Rocks Of The Mbozi Gabbro Syenite Complex Sw–Tanzanian, East Africa, M.K.D. Mutakyahwa Dec 1995

Weathering On The Alkaline Rocks Of The Mbozi Gabbro Syenite Complex Sw–Tanzanian, East Africa, M.K.D. Mutakyahwa

Tanzania Journal of Science

The Mbozi gabbro syenite complex is about 800 Ma and is associated with the Bukoban tectonic episode. Tectonically it follows the regional strike direction of the Ubendian System, which is a part of the polycyclic Mozambique mobile belt. The complex is a typical ring structure with the central part down-faulted. Deep weathering profiles on the ring structure were developed on a peneplain and as a result of uplift intersected hilly landscape of early tertiary times. The truncated 5-15m thick weathering profiles occur on three rock types, olivine gabbro, pyroxenite and nepheline perthite syenite (pethoste). The chemical and mineralogical processes of …


Geology Newsletter- 1995, Department Of Geology Dec 1995

Geology Newsletter- 1995, Department Of Geology

Geological and Environmental Sciences News

Vol. 1, No. 20

  • Faculty News
  • Awards and Scholarships
  • Alumni/ Friends/ Former Faculty Notes
  • Geology Development and Scholarship Donations
  • New Alumni


Evaluation Of Bail-Down Test Methods For Characterizing Free Product Recoverability From An Aquifer, Laura L. Krol Dec 1995

Evaluation Of Bail-Down Test Methods For Characterizing Free Product Recoverability From An Aquifer, Laura L. Krol

Masters Theses

Determination of the occurrence and recoverability of free product impacting the subsurface environment has been an on-going challenge in the environmental industry. A simple and relatively inexpensive test to perform in the field is the free product bail-down test. Many authors have proposed various analysis methods using these data for the determination of different free product characteristics.

The purpose of this project was to determine the comparability and possible validity of bail-down test interpretation methods for predicting hydrocarbon hydraulic conductivity/transmissivity and true free product thickness. Bail-down test data collected from two sites were analyzed and interpreted using methods from the …


The Effects Of Air Sparging On Aquifer Hydraulic Conductivity, Hans Neve Dec 1995

The Effects Of Air Sparging On Aquifer Hydraulic Conductivity, Hans Neve

Masters Theses

Air sparging is a relatively new technology used to remove organic contaminants from aquifers. This remediation technique involves injecting into contaminated portions of water table aquifers. Theoretically air sparging will reduce aquifer hydraulic conductivity. Injected air fills some of the available sediment pores, thus restricting the flow of water to the remaining water-filled pore spaces.

The purpose of this study was to measure the reduction in hydraulic conductivity due to air sparging. This was assessed using both laboratory and field techniques. The hydraulic conductivities of several different sediments were determined in the laboratory using a large constant head permeameter modified …


The Petrology Of The Precambrian Roof Pendants Thompson Peak, Sawtooth Mountains, Idaho, Susan Denise Anderson Dec 1995

The Petrology Of The Precambrian Roof Pendants Thompson Peak, Sawtooth Mountains, Idaho, Susan Denise Anderson

Honors Capstones

No abstract provided.


Mafic Volcanism In The Colorado Plateau: Basin And Range Transition Zone, Hurricane, Utah, Alexander Sanchez Dec 1995

Mafic Volcanism In The Colorado Plateau: Basin And Range Transition Zone, Hurricane, Utah, Alexander Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Hurricane volcanic field (HVF) is a small-volume (0.48 km3) mafic volcanic field in the Colorado Plateau/Basin & Range Transition Zone located in the eastern part of the St. George basin in southwestern Utah. Strombolian-Hawaiian style eruptions produced thin (10 m) a'a lava flows and cinder (scoria) cones composed of vesicular basalt, bombs and agglutinate. Radiometric dating and geologic relationships demonstrate that the HVF formed over a period of at least 100,000 years. In the upper crust, magma probably rose along joints in sedimentary rocks because chains of volcanic vents follow joint orientation maxima in sedimentary rocks.

Three …


Tectonic Denudation Of Mesozoic Contractile Structures By A Low-Angle Normal Fault And Associated Faults, Southern White Pine Range, Nevada, Holly Langrock Dec 1995

Tectonic Denudation Of Mesozoic Contractile Structures By A Low-Angle Normal Fault And Associated Faults, Southern White Pine Range, Nevada, Holly Langrock

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Blackrock Canyon area in the southern White Pine Range, Nevada mostly consists of the highly extended upper plate of a low-angle normal fault, the Blackrock fault. The post-31.3 Ma Blackrock fault places upper Paleozoic sedimentary rocks and overlying Tertiary volcanic rocks of the Garret Ranch Group in its hangingwall against a 50 degrees E-dipping homocline of Cambrian through Mississippian rocks in its footwall. The 15 to 30 degrees W-dipping Blackrock fault is non-planar and consists of two fault segments and a pronounced corrugation, the Bull Spring corrugation. These geometric irregularities suggest the slip direction on the fault was east-southeast …


Geology And Geochemistry Of Tertiary Volcanic Rocks In The Northern Reveille And Southern Pancake Ranges, Nye County, Nevada, Kelly Brian Rash Dec 1995

Geology And Geochemistry Of Tertiary Volcanic Rocks In The Northern Reveille And Southern Pancake Ranges, Nye County, Nevada, Kelly Brian Rash

UNLV Theses, Dissertations, Professional Papers, and Capstones

The northern Reveille and southern Pancake Ranges, located in the south-central Great Basin, experienced a prolonged history of Tertiary volcanism. Volcanic activity in this area began with the eruption of large-volumes of ash-flow tuffs from calderas of the central Nevada caldera complex. The Reveille Range and the southernmost portion of the Pancake Range are the site of two calderas that are the sources for the tuff of Goblin Knobs and tuff of northern Reveille Range. The tuff of Goblin Knobs (70.4-75.3 wt.% SiO2) erupted from the caldera of Goblin Knobs (25.6 Ma) and is the thickest (~1700 m) …


Geochemical Evolution Of A Mid-Miocene Synextensional Volcanic Complex: The Dolan Springs Volcanic Field, Northwestern Arizona, Scott Michael Mcdaniel Dec 1995

Geochemical Evolution Of A Mid-Miocene Synextensional Volcanic Complex: The Dolan Springs Volcanic Field, Northwestern Arizona, Scott Michael Mcdaniel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Dolan Springs volcanic field (DSV), of northwestern Arizona, is dominated by andesite and basaltic-andesite flows and breccias, with minor amounts of basalt, rhyolite, and ash-flow tuff. Geochemistry is used here as a tool to evaluate the roles and contributions of the lithospheric and asthenospheric mantles to magmatism related to Miocene extension in the Colorado River extension corridor (CREC). The majority of synextensional volcanic rocks in the DSV are geochemically similar to regional trends, but rare tholeiitic basalts erupted near the end of extension. The tholeiites have trace element signatures similar to ocean island basalt (OIB), but have isotopic values …


Silica Spherules In Chrysoprase From Haneti-Itiso Area, Cental Tanzania, E.P. Malisa Dec 1995

Silica Spherules In Chrysoprase From Haneti-Itiso Area, Cental Tanzania, E.P. Malisa

Tanzania Journal of Science

Apple green gem quality chrysoprase from haneti-Itiso area, central Tanzania was studied. Under the microscope the chrysoprase shows highly disordered spherules which are concentric. Composed of bipyramidal quartz, chalcedony quartzite and opal-A. The spherules were classified into four main types according to the shell arrangement. The diameter of the spherules ranged from 40 μm 77 μm. Fluid inclusion types in bipyramidal quartz were monophasic low temperature type. Mineralogical properties indicated refractive indices to be 1.548 to 1.553 (±0.002), mean specific gravity 2.56, hardness about 7 on Moho’s scale, inert to ultraviolet radiation, green though Chelsea filter, and absorption in the …


The Variability Of Carbon Dioxide In The Vadose Zone, John J. Ring Dec 1995

The Variability Of Carbon Dioxide In The Vadose Zone, John J. Ring

Masters Theses

The purpose of this thesis was to observe and attempt to explain the variations of carbon dioxide in the vadose zone of a nature area in southwestern Michigan. Well nests, consisting of discrete soil gas sampling points and temperature probes set at depths ranging from 3 to 53 feet, were constructed in a sandy, glacial outwash plain. Soil samples were collected for analysis of organic carbon content during installation. Soil gas samples were collected periodically from June, 1992 to March, 1993 and analyzed for CO2 and O2 concentrations. Occasionally, samples were collected and analyzed for isotopic C13 …


Soil Acidity. A Reference Manual., Linda Leonard, Mike D. Bolland Dec 1995

Soil Acidity. A Reference Manual., Linda Leonard, Mike D. Bolland

Natural resources published reports

This publication is intended as a guide for consultants, development officers and field representatives for the extension of soil acidity in Western Australia.

Most Western Australian soils are naturally acidic. Acid peaty sands in the high rainfall area of the South West are the only W.A. soils in which natural acidity has been treated routinely before productive agriculture was introduced. There are approximately 100, 000 hectares of acid, peaty sands scattered through coastal districts between Pemberton and Rocky Gully districts.