Digital Commons 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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- Southeastern Glacial Drift Area, D. C. Gosselin

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Factors Affecting Attwater's Prairie-Chicken Decline On The Attwater Prairie Chicken, Michael E. Morrow, Robert S. Adamcik, Jenny D. Friday, Lloyd B. Mckinney

United States Geological Survey: Staff Publications

We examined the association between changes in the number of Attwater's prairie-chicken (Tympanuchus cupido attwateri) on the Attwater Prairie Chicken National Wildlife Refuge from 1972 to 1993 and changes in refuge management practices (burning and grazing). We also examined the relationship of prairie-chicken population increases and decreases on the refuge to rainfall and off-refuge prairie-chicken populations. Burning within the prairie-chicken's core habitat on the refuge and variability in grassland structure were directly correlated (P < 0.05) with increases and declines in prairie-chicken populations. Refuge population increases and declines were inversely correlated (P < 0.1) with average April rainfall/event, May absolute departure from long-term average rainfall, May number of rainfall events, annual absolute departure of rainfall from the long-term average, and the annual number of rainfall events. Refuge population increases and declines were directly correlated (P < 0.1) with off-refuge populations, although the off- refuge population decline began 4 years earlier than on-refuge.

Occurrence Of Selected Pesticides And Their Metabolites In Near-Surface Aquifers Of The Midwestern United States, Dana Kolpin, E. Michael Thurman, Donald Goolsby

United States Geological Survey: Staff Publications

The occurrence and distribution of selected pesticides and their metabolites were investigated through the collection of 837 water-quality samples from 303 wells across the Midwest. Results of this study showed that five of the six most frequently detected compounds were pesticide metabolites. Thus, it was common for a metabolite to be found more frequently in groundwater than its parent compound. The metabolite alachlor ethanesulfonic acid (alachlor- ESA; 2-[(2,6-diethylphenyl)(methoxymethyl)amino]-2- oxoethanesulfonic acid) was detected almost 10 times as frequently and at much higher concentrations than its parent compound alachlor (2-chloro-2',6'- diethyl-N-(methoxymethyl)acetamide). The median detectable atrazine (2-chloro-4-ethylamino-6- isopropylamino-s-triazine) concentration was almost half that …

Acetochlor In The Hydrologic System In The Midwestern United States, 1994, Dana Kolpin, Brenda Nations, Donald Goolsby, E. Michael Thurman

United States Geological Survey: Staff Publications

The herbicide acetochlor [2-chloro-N-(ethoxymethyl)- N-(2-ethyl-6-methylphenyl)acetamide] was given conditional registration in the United States by the U.S. Environmental Protection Agency in March 1994. This registration provided a rare opportunity to investigate the occurrence of a pesticide during its first season of extensive use in the midwestern United States. Water samples collected and analyzed by the U.S. Geological Survey during 1994 documented the distribution of acetochlor in the hydrologic system; it was detected in 29% of the rain samples from four sites in Iowa, 17% of the stream samples from 51 sites across nine states, and 0% of the groundwater samples from …

Estimation And Abundances In Two-Component Mineral Mixtures Using Mid-Infrared Laser Reflectance Ratios, Ram M. Narayanan, Kristin K. Warner, Robert F. Diffendal Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

The mid-infrared spectral region (8-14 μm wavelength) is emerging as a viable geologic remote sensing tool due to the presence of reststrahlen bands for minerals such as silicates and carbonates. An experimental study was carried out to characterize the mid-infrared laser reflectance of mineral mixtures, and to explore the potential of laser remote sensing systems to estimate mineral abundances in two-component mixtures. An empirical model was developed to establish a relationship between laser reflectance ratios at judiciously selected wavelengths and percentage of one of the minerals in the mixture. It was found that the abundances can be estimated to within …

Multiport Well Design For Sampling Of Ground Water At Closely Spaced Vertical Intervals, Geoffrey N. Delin, Matthew K. Landon

United States Geological Survey: Staff Publications

Detailed vertical sampling is useful in aquifers where vertical mixing is limited and steep vertical gradients in chemical concentrations are expected.

Late Pliocene Diatoms In A Diatomite From Prydz Bay, East Antarctica, Albert D. Mahood, John A. Barron

United States Geological Survey: Staff Publications

Very well-preserved Pliocene diatoms from a diatomite unit interbedded within glacial sediments at Ocean Drilling Program Site 742 in Prydz Bay, Antarctica are documented and illustrated. The presence of Thalassiosira kolbei, T torokina, Actinocyclus actinochilus, A karstenii and the absence of Nitzschia interfrigidaria, T. insigna and T. vulnifica in Sample 119-742A-15R-4, 44-46 cm constrain its age to ca. 2.2-1.8 Ma (late Pliocene). Diatoms associated with sea ice constitute 35% of the Pliocene diatom assemblage, compared with 71% of the modern sediment assemblage at the site, suggesting that sea ice was present during the late Pliocene period of deposition of the …

Detailed Observations Of California Foreshock Sequences: Implications For The Earthquake Initiation Process, Douglas A. Dodge, Gregory C. Beroza, W. L. Ellsworth

United States Geological Survey: Staff Publications

We find that foreshocks provide clear evidence for an extended nucleation process before some earthquakes. In this study, we examine in detail the evolution of six California foreshock sequences, the 1986 Mount Lewis (M_L = 5.5), the 1986 Chalfant (M_L = 6.4), the 1986 Stone Canyon( M_L = 4.7), the 1990 Upland (M_L = 5.2), the 1992 Joshua Tree (M_w= 6.1), and the 1992 Landers (M_w = 7.3) sequence. Typically, uncertainties in hypocentral parameters are too large to establish the geometry of foreshock sequences and hence to understand their evolution. However, the similarity …

Effect Of Nitrate, Organic Carbon, And Temperature On Potential Denitrification Rates In Nitrate-Rich Riverbed Sediments, K. S. Pfenning, P. B. Mcmahon

United States Geological Survey: Staff Publications

A study conducted in 1994 as part of the US Geological Survey's National Water-Quality Assessment Program, South Platte River Basin investigation, examined the effect of certain environmental factors on potential denitrification rates in nitrate-rich riverbed sediments. The acetylene block technique was used to measure nitrous oxide (N₂O) production rates in laboratory incubations of riverbed sediments to evaluate the effect of varying nitrate concentrations, organic carbon concentrations and type, and water temperature on potential denitrification rates. Sediment incubations amended with nitrate, at concentrations ranging from 357 to 2142 μmol 1^-1 (as measured in the field), produced no significant …

Climatic And Hydrologic Oscillations In The Owens Lake Basin And Adjacent Sierra Nevada, California, Larry Benson, James W. Burdett, Michaele Kashgarian, Steve Lund, Fred Phillips, Robert O. Rye

United States Geological Survey: Staff Publications

Oxygen isotope and total inorganic carbon values of cored sediments from the Owens Lake basin, California, indicate that Owens Lake overflowed most of the time between 52,500 and 12,500 carbon-14 (¹⁴C) years before present (B.P.). Owens Lake desicated during or after Heinrich event H1 and was hydrologically closed during Heinrich event H2. The magnetic susceptibility and organiz carbon content of cored sediments indicate that about 19 Sierra Nevada glaciations occurred between 52,500 and 23,500 ¹⁴C years B.P.

Origin Of The Late Quaternary Dune Fields Of Northeastern Colorado, Daniel R. Muhs, Thomas W. Stafford, Scott D. Cowherd, Shannon A. Mahan, Rolf Kihl, Paula B. Maat, Charles A. Bush, Jennifer Nehring

United States Geological Survey: Staff Publications

Stabilized eolian deposits, mostly parabolic dunes and sand sheets, cover much of the landscape of northeastern Colorado and adjacent parts of southwestern Nebraska in four geographically distinct dune fields. Stratigraphic and soil-geomorphic relations and accelerator radiocarbon dating indicate that at least three episodes of eolian sand movement occurred between 27 ka and 11 ka. possibly between 11 ka and 4 ka. and within the past 1.5 ka. Thus, eolian sand deposition took place under both glacial and interglacial climatic conditions. In the youngest episodes of eolian sand movement. Holocene parabolic dunes partially buried Pleistocene sand sheet deposits.

Late Holocene sands …

A Functional Group Approach To Detecting Shifts In Macroalgal Communities Along A Disturbance Gradient, J. C. Phillips

Theses : Honours

A recently proposed hypothesis argued that morphologically and functionally similar macroalgae could be grouped to study the structure of macroalgal communities. It was argued that these functional groups can be used to predict changes to community composition that result from disturbance. This study examined whether the functional group model held in detecting changes in macroalgal community structure within one bioregion, by applying it to a habitat exposed to different levels of physical disturbance associated with wave exposure. Results obtained using a functional group approach were compared to those obtained using a species level approach. Three parallel reef lines in Marmion …

Soil Information Sheets For Part Of The Jerramungup Agricultural Area, Tim D. Overheu, Landcare Western Australia, Jerramungup Land Conservation District Committee

Agriculture reports

Each sheet summarises information on the soil's characteristic properties, and associated land use suitability and management. A photograph of a representative profile is provided for each soil. Technical terms are defined in soil sheet glossary. Information is presented under the following headings: soil series and groups, occurence, native vegetation, soil profile description, characteristic soil properties, soil classification and agricultural land use and management.

Soil Information Sheets For The Mount Beaumont, Mallee And Esperance Agricultural Areas, Department Of Agriculture And Food, Landcare Western Australia, Esperance Land Conservation District Committee, Mount Beaumont / Howick Catchment Group (W.A.)

Agriculture reports

Each sheet summarises information on the soil's characteristic properties, and associated land use suitability and management. A photograph of a representative profile is provided for each soil. Technical terms are defined in soil sheet glossary. Information is presented under the following headings: soil series and groups, occurence, native vegetation, soil profile description, characteristic soil properties, soil classification and agricultural land use and management.

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 …

Synthetic Organic Compounds: Las Vegas Wash And Lake Mead, National Water Quality Assessment Program (Nawqa): Nevada Basin And Range

Publications (WR)

The Nevada Basin and Range (NVBR) study unit of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is investigating the status of, trends in, and factors affecting water quality in the Las Vegas area. A principal objective of the investigation is to assess the effects of urbanization on the quality of area water resources. Las Vegas Wash is the surface-water outlet for the Las Vegas area. The wash transports stormwater runoff, shallow ground-water discharge, and tertiary-treated sewage effluent from the Las Vegas area to Las Vegas Bay of Lake Mead on the Colorado River. Most of the flow—about 96 …

A Coupled, Non-Linear, Steady State Model For Early Diagenetic Processes In Pelagic Sediments, Surya P. Dhakar, David J. Burdige

OES Faculty Publications

A steady state, coupled, non-linear model has been developed for early diagenetic processes in pelagic and hemi-pelagic marine sediments. Model results show that the occurrence of oxic and sub-oxic diagenetic processes is significantly affected by variations in parameters such as the sedimentation rate, bioturbation coefficient, sediment porosity, and organic matter flux to the sediments. Increases in the sedimentation rate or the bioturbation coefficient increase organic matter oxidation by sub-oxic processes, whereas an increase in sediment porosity decreases organic matter oxidation by sub-oxic processes. Sediment data from three contrasting MANOP sites are fit reasonably well with the model. The resulting best-fit …

Biogenic Matter Diagenesis On The Sea Floor: A Comparison Between Two Continental Margin Transects, William M. Berelson, Jim Mcmanus, Kenneth H. Coale, Kenneth S. Johnson, Tammy Kilgore, David J. Burdige, Cynthia Pilskaln

OES Faculty Publications

Benthic chamber measurements of the reactants and products involved with biogenic matter diagenesis (oxygen, ammonium, nitrate, silicate, phosphate, TCO₂, alkalinity) were used to define fluxes of these solutes into and out of the sediments off southern and central California. Onshore to offshore transects indicate many similarities in benthic fluxes between these regions. The pattern of benthic organic carbon oxidation as a function of water depth, combined with published sediment trap records, suggest that the supply of organic carbon from vertical rain can just meet the sedimentary carbon oxidation + burial demand for the central California region between the …

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

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 …

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 …

A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare

Masters Theses

Over a two year period, Western Michigan University ran a number of pump tests in the Asylum Lake Area in Kalamazoo, Michigan. The transmissivities and storativities calculated from these tests differed significantly from well to well in any particular test, and from pump test to pump test. Utilizing the computer programs AQTESOLV 3.0 and Aquifer Parameter Estimator, a number of T and S values were calculated. After analysis of the results, the following conclusion was drawn. The main reason for the deviations in the T and S values arose from the mixing of the results of numerous methods (some of …

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 C^{13 …}

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 …

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 …

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.

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) …

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

Honors Capstones

No abstract provided.

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 …