Earth Sciences Commons^™

Residual Values Of Different Molybdenum Sources, M M. Riley

Experimental Summaries - Plant Research

To examine the declines in effectiveness of different sources of molybdenum. 84Me10

Resource Notes-Spring/Summer 1987

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Stockwork Tungsten (Scheelite)-Molybdenum Mineralization, Lake George, Southwestern New Brunswick, Robert R. Seal Ii, Alan Clark, Charles Morrissy

United States Geological Survey: Staff Publications

Scheelite-molybdenite stockwork mineralization constitutes one component of the Lake George polymetallic (Sb-W-Mo-Au-base metal) deposit, a complex hydrothermal center of Late Silurian (ca. 412 m.y.) age in the Fredericton trough of the northern Appalachians. The stockwork, hosted by Silurian graywackes, in part calcareous, is spatially and temporally related to a postkinematic cupola of biotite monzogranite, and its formation overlapped in time with the emplacement of monzogranitic porphyry dikes. Mineralogical and textural evidence indicates that contact metamorphism associated with the cupola had ceased before the initiation of W-Mo mineralization and that it occurred, at pressures of less than 1.75 kb, in two …

The Effect Of Particle Size On Phosphate Adsorption By Fluvial Sediment, Michael F.A. Stone

Theses and Dissertations (Comprehensive)

The quantitative phosphate adsorption behaviour of ten grain size fractions of an experimental sediment (silica sand) and fluvial sediment from two Southwestern Ontario rivers, were evaluated and compared to determine the effect of particle size on phosphate absorption. In addition, the elemental composition of grain size fractions of fluvial sediment were determined by X-Ray fluorescence spectrometry to study the combined effect of particle size and sediment geochemical composition on phosphate adsorption. Results of the adsorption studies indicate that phosphate adsorption per unit mass increases in non-linear fashion with decreasing grain size. The capacity of grain size fractions of silica sand …

History Of Cultural Eutrophication At Lake Manitou, Indiana And Prospects For Its Management, Thomas Crisman

School of Geosciences Faculty and Staff Publications

No abstract provided.

Petrographic Criteria For The Recognition Of 'Magadi-Type' Cherts, Kathryn A. Schubel

Honors Papers

The Magadi cherts, inorganic lacustrine deposits from the Lake Magadi area, Kenya, are widely used as a modern analog to explain the origin of ancient inorganic cherts. Formed in a highly alkaline lake, as the result of a transformation from the sodium silicates minerals, magadiite and/or kenyaite, to quartz, the Magadi cherts possess a distinctive set of textural characteristics that allow them to be distinguished from cherts of different origin with only a limited number of samples. Textural characteristics that are diagnostic of the Magadi cherts and that can be used as a test for the occurrence of ancient 'Magadi-type' …

Carbonate Surface Solution In The Classical Karst, Franco Cucchi, Fabio Forti, Furio Finocchiaro

International Journal of Speleology

The current research on the dissolution of carbonate rocks in the Karst of Trieste indicates that the average degradation of surfaces exposed to atmospheric agents is 0.028 mm/year with an average rainfall of 1350 mm. The maximum levels (0.031 mm/year) correspond to micro-crystalline limestones, the minimum values (0.014 mm/year) to dolomites.

Irrigation Water Use In Southern Ontario, Kenneth Iain Macdonald

Theses and Dissertations (Comprehensive)

The appreciation of water as a finite resource has engendered a renewed research interest in producing effective water management policies and practices in order to reduce both current and potential demands on existing reserves. Unfortunately, such research, especially in the humid regions of North America, has concentrated on water use in urban areas and has neglected the use of water in irrigation agriculture; even though irrigation is a major consumptive use of water in many localized areas. In addition, research has been dominated by physical, technological and economic viewpoints at the expense of an understanding of the human element in …

Food-Finding Ability In Cave Fish (Astyanax Fasciatus), Kathrin Hüppop

International Journal of Speleology

When competing under cave similar conditions, such as darkness and food scarcity, cave fish find much more food than their epigean relatives. The cave fish not only react much faster to food but also their food-finding ability is four times higher compared to that of the epigean fish. Several morphological and ethological alterations in the cave fish, described by other authors, seem to be responsible for this adaptation to the cave conditions.

Genetic Analysis Of Evolutionary Processes, Horst Wilkens

International Journal of Speleology

Epigean and cave populations of A. fasciatus (Characidae, Pisces) differ in a series of morphological physiological, and ethological features. The interfertility of these populations made possible a genetic analysis of organs characteristic of interspecific divergence. The study of the regressive organs “eye” and “melanophore system” on the one hand and that of the constructively improved “gustatory equipment" and "feeding behaviour” on the other yielded identical principles of genetic manifestation: (1) All features have a polygenic basis with an at least di- to hexahybrid inheritance. (2) All polygenes have the same amount of expressivity. (3) After recombination of a minimum number …

Paleoenvironmental Data For N. W. Georgia, U.S.A., From Fossils In Cave Speleothems, George A. Brook, Eugene P. Keferl, Rudy J. Nickmann

International Journal of Speleology

Pollen grains and gastropod shells in two speleothems from Red Spider Cave, Georgia indicate that ca. 10,000 yr B.P. the vegetation near the cave was Mixed Mesophytic Forest. Conditions were cooler and moister than today and a shallow pond existed in the doline above the cave. As these findings support palynologic evidence from nearby pond sites it is clear that cave speleothems are a potential source of paleoecological data to ca. 350,000 yr. B.P.

Depositional And Diagenetic History Of The Middle Ordovician Carbonates Of The Shenandoah Valley, Northern Virginia, Lynn Ellen Weyenberg

OES Theses and Dissertations

An examination of the Middle Ordovician carbonates in northwest Virginia has revealed a particularly sensitive record of deposition and subsidence. Two-hundred acetate peels from six measured stratigraphic sections in Shenandoah County, Virginia were examined to interpret the depositional and diagenetic history. Two major lithofacies have been recognized within the New Market Limestone and three have been recognized in the Lincolnshire Formation. These five lithofacies represent an overall transgressive sequence. This transgression was not uniform but paused several times to allow carbonate deposition to reach sea-level. These shoaling events suggest a slowly subsiding basin in this region. The carbonate rocks within …

The Hydrogeology Of Nags Head Woods, Dare County, North Carolina, Janet Salyer Emry

OES Theses and Dissertations

Nags Head Woods, a coastal maritime forest located on a barrier island in eastern North Carolina, stabilizes a back-barrier dune system bordering a tidal marsh. The purpose of this study is to provide basic information about the groundwater geology in Nags Head Woods and to predict the effects upon water levels due to municipal pumping of Fresh Pond, a large lake near the center of the island.

Clean, fine-to-medium sands dominate the top of the surficial (water table) aquifer, underlain by silty fine-to-coarse sands at -4 m elevation. A silty clay bed of very low permeability is present at -12 …

Trace Fossils In Carbonate Upper Beach Rocks And Eolianites: Recognition Of The Backshore To Dune Transition, H. Allen Curran, Brian White

Geosciences: Faculty Publications

Reprinted from: H. Allen Curran (ed.), Proceedings of the Third Symposium on the Geology of the Bahamas: Fort Lauderdale, Florida, CCFL Bahamian Field Station

Coral Reef To Eolianite Transition In The Pleistocene Rocks Of Great Inagua, Bahamas, Brian White, H. Allen Curran

Geosciences: Faculty Publications

Great Inagua Island, the southernmost of the chain of Bahamian islands, lies approximately 100 km northeast of the eastern tip of Cuba. This paper reports the results of reconnaissance geologic field work conducted on Great Inagua Island in January, 1985, and of more detailed observations made in January, 1986, near Matthew Town, between South West Point and Devil's Point.

15N/14N Variations In Cretaceous Atlantic Sedimentary Sequences: Implication For Past Changes In Marine Nitrogen Biogeochemistry, Greg H. Rau, Michael A. Arthur, Walter E. Dean

United States Geological Survey: Staff Publications

At two locations in the Atlantic Ocean (DSDP Sites 367 and 530) early to middle Cretaceous organic-carbon-rich beds ("black shales") were found to have significantly lower δ¹⁵N values (lower ¹⁵N/¹⁴N ratios) than adjacent organic-carbon-poor beds (white limestones or green claystones). While these lithologies are of marine origin, the black strata in particular have δ¹⁵N values that are significantly lower than those previously found in the marine sediment record and most contemporary marine nitrogen pools. In contrast, black, organic-carbon-rich beds at a third site (DSDP Site 603) contain predominantly terrestrial organic matter and have …

Genesis Of Marine Terrace Soils, Barbados, West Indies: Evidence From Mineralogy And Geochemistry, Daniel R. Muhs, Russell C. Crittenden, John N. Rosholt, Charles A. Bush, Kathleen C. Stewart

United States Geological Survey: Staff Publications

Well-developed, clay-rich soils dominated by interstratified kaolinite-smectite are found on the uplifted coral reef terraces on the island of Barbados. The reef limestone is unlikely to have been the soil parent material however, because it is 98 per cent CaCO, and geomorphic evidence argues against the 20 m of reef solution required to produce the soils by this process. The mineralogy of the sand, silt, and clay fractions of the soils, and trace element geochemistry, suggest that aeolian materials carried on the trade winds from Africa, volcanic ash from the island of St. Vincent, and quartz from Tertiary bedrock on …

Mesodictyon, A New Fossil Genus Of The Centric Diatom Family Thalassiosiraceae From The Miocene Chalk Hills Formation, Western Snake River Plain, Idaho, Edward Theriot, J. Platt Bradbury

United States Geological Survey: Staff Publications

Three new centric diatom species assigned to a new genus are described from Miocene lacustrine deposits of Idaho. Species of the new genus, Mesodictyon, have the areola cribrum in the middle of the loculus, strutted processes and radiating, non-fasciculated striae. The strutted processes of M. magnum (diameter 60-150 μm) have long (2-3 μm) tubular extensions. The strutted processes of M. fovis (diameter 14-80 μm) are in distinct pits near the junction of the face and mantle. The valve face of M. undulatum (diameter 10-44 μm) is weakly tangentially undulate. Preliminary evidence indicates that Mesodictyon has a wide geographic distribution …

Stable Isotope Compositions Of Fossil Mollusks From Southern California: Evidence For A Cool Last Interglacial Ocean, Daniel R. Muhs, T. Kurtis Kyser

United States Geological Survey: Staff Publications

Stable isotope compositions have been determined for modem mullusks and fossil mollusks collected from uplied marine terraces at three l d t i e s in southern California. By using a paleocliatic model that decouples the temperature and ice-volume signals in ocean water, ocean-water temperatures off southern California are estimated to have been -3.8 °C at ~85 ka, -3.0 °C at ~107 ka, and -2.2 °C at ~125 ka relative to present temperature. These results indicate rather cool conditions during the peak of the last interglacial stage at 125 ka and conflict with results from terrace faunal studies that suggest …

Lungfish Burrows In The Upper Triassic Chinle And Dolores Formations, Colorado Plateau, Russell F. Dubiel, Robert H. Blodgett, Thomas M. Bown

United States Geological Survey: Staff Publications

Vertical-to-inclined, cylindrical trace fossils that occur in the Upper Triassic Chinle and Dolores Formations on the Colorado Plateau are interpreted to be the casts of lungfish burrows. The casts, which are as much as 11 cm in diameter and as much as 1.6 m long, were formed by passive siliciclastic and carbonate sedimentation into apparently abandoned lungfish burrows. Locally, the burrow fillings are overwhelmingly abundant, and many intersect and have destroyed former burrow fillings. Superposition of bioturbation episodes has obliterated most primary sedimentary structures. This bioturbation has contributed to the mottled coloration and the knobby-weathering texture of the rocks. The …

Patterns Of Dental Evolution In Early Eocene Anaptomorphine Primates (Omomyidae) From The Bighorn Basin, Wyoming, Thomas M. Bown, Kenneth D. Rose

United States Geological Survey: Staff Publications

ABSTRACT--The subfamily Anaptomorphinae contains the oldest and most generalized members of the tarsier-like primates and is the basal group of the extinct family Omomyidae. The best and most continuous record of anaptomorphine history is from rocks of early Eocene (Wasatchian) age in the Bighorn Basin of northwest Wyoming where eight genera and 14 species are recognized. Three of these species are new (Teilhardina crassidens, Tetonius matthewi, Absarokius metoecus), and four other new species are described from elsewhere (Tetonius mckennai, Absarokius gazini, A. australis, Strigorhysis huerfanensis). Teilhardina tenuicula and Absarokius nocerai are …

Sedimentology Of The Upper Triassic Chinle Formation Southeastern Utah: Paleoclimatic Implications, Russell F. Dubiel

United States Geological Survey: Staff Publications

The Upper Triassic Chinle Formation in southeastern Utah was deposited in a complex fluvial-deltaic-lacustrine system. The Chinle records the evolution of a continental system in response to variations in climate, tectonics, and sediment supply. Chinle strata represent deposits of fluvial channels and floodplains, lacustrine deltas, lacustrine basins, and lacustrine and playa mudflats. These rocks include a variety of vertebrate, invertebrate, and plant fossils, trace fossils, and paleosols that provide information on depositional environments, water tables, and paleoclimate.

Sedimentologic and paleontologic interpretations both support an interpretation of abundant lakes, streams, and marshes with high, but fluctuating water tables for all but …

Conservation And Survey Division. 1987. Significant Rises And Declines In Nebraska Groundwater Levels (From Pre-Development As Of Fall 1985)/Registered Irrigation Wells In Nebraska (As Of January 1, 1986), Conservation Survey Division, U.S. Geological Survey

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Nebraska Mineral Operations Review, 1986, Raymond R. Burchett, Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Analysis And Interpretation Of Ice-Deformed Sediments From Harrison Bay, Alaska, Steven A. Fischbein

Department of Earth and Atmospheric Sciences: Faculty Publications

The surficial sediments present on the continental shelf off the north coast of Alaska in the vicinity of Harrison Bay consist dominantly of fine grained sand, silt, and mud that were deposited during Holocene time. Depositional environments in Harrison Bay range from outer shelf to prodelta and delta front. Ice sediment interaction has overprinted structural deformation on many of the sediments present in Harrison Bay, and has in some cases obliterated the original lithologic continuity of the sediments. Ice related deformation ranges from simple loading features to more complex folded and faulted structures. A hypothetical model has been proposed which …

Diatom, Contributors Of Coralloid Speleothems, From Togawa-Sakaidani-Do Cave In Miyazaki Prefecture, Central Kyushu, Japan, Naruhiko Kashima, Teruo Irie, Nobuhiro Kinoshita

International Journal of Speleology

Coralloid speleothems are commonly distributed in Togawa-Sakaidani-do Cave in Miyazaki Prefecture, Central Kyushu, but their speleological study has not heretofore been achieved. Light and scanning microscopes analyses revealed that coralloid speleothems consist of alternating layers of diatom colonies, detrital minerals and clay. Electron microprobe analysis shows coralloid speleothems to be silicious. This paper asserts that diatom (genus Melosira) is one of the important contributors to siliceous coralloid speleothems in the threshold zone at non-calcareous caves.

Relationships Between The Internal And External Evolution Of The Monte Cucco Karst Complex, Umbria, Central Italy, Fausto Guzzetti

International Journal of Speleology

The relationships between the internal and external evolution of the Mt. Cucco karst complex are studied. A classic set of equations, involving the oxidation of hydrogen sulphide, originated at depth in an evaporitic formation, is used to explain the presence of massive gypsum deposits in the Mt. Cucco and the Faggeto Tondo caves. The distribution and the morphology of more than 30 caves in the system, the presence of gypsum, always located along faults, and the presence of broken stalactites and columns, suggest that the evolution of the karst system has been controlled by tectonic movements. Relationships between the development …

Coarsening Of Fine-Scale Exsolution Lamellae, John B. Brady

Geosciences: Faculty Publications

Diffusional exchange between the wedge-shaped terminations of fine-scale, coherent exsolution lamellae and the large flat sides of adjacent like lamellae is proposed as the principal mechanism for the coarsening of lamellar exsolution textures in silicate minerals. Following the methods of Gibbs (1906), a formula is derived for the chemical potential gradients due to interfacial energy effects that drive the proposed diffusion and coarsening....

A Gravity And Magnetic Study Of The Crooked Creek Cryptoexplosion Structure, Crawford County, Missouri, Charles Edward Woodbury

Masters Theses

"The pre-Pennsylvanian structure at Crooked Creek consists of a complex, vertically faulted ring of Cambrian and Ordovician sediments with a central uplifted core. The center of the structure is strongly deformed and contains shatter cones, brecciation, and other signs of extreme shock.

A magnetic low over the center of the structure suggests that igneous material was not involved in the formation of the structure, and this is corroborated by core analysis. Gravity data indicates several small gravity lows, possibly associated with areas of brecciation, circling the flanks of the structure. As in the magnetic data, there is no indication that …

Lithofacies Analysis Of The Lamotte Sandstone In South Central Missouri, Michael Gerard Kraenzle

Masters Theses

"Based on the analysis of thirty-one cores obtained from the Missouri Department of Natural Resources in Rolla, the upper Cambrian Lamotte Sandstone in South Central Missouri has been divided into six sedimentary facies ranging from alluvial fan and braided stream to open marine.

The Lamotte Sandstone is the basal Cambrian sandstone found throughout most of the state of Missouri. It directly overlies late Precambrian (1.4 to 1.5 billion year old) granites and metasediments. The Lamotte and overlying Bonneterre Formations are generally considered to have been deposited by a transgression which occurred during the Late Cambrian Period (Croixian Epoch).

The Lamotte …