Physical Sciences and Mathematics Commons^™

Groundwater Flow In A Compressible Unconfined Aquifer With Uniform Circular Recharge, Vitaly A. Zlotnik, Glenn Ledder

Department of Earth and Atmospheric Sciences: Faculty Publications

The distributions of the hydraulic head and velocity components of the transient groundwater flow in an unconfined compressible aquifer of finite thickness under constant uniform circular recharge are obtained from the linearized mathematical model by the use of integral transforms. The result generalizes Dagan’s (1967) solution which was derived by neglecting the compressibility. By treating the compressibility parameter as a small value, the formula for the hydraulic head is analyzed by asymptotic methods, resulting in approximations to the exact solutions for the head and velocities on small and large time scales. The hydraulic head and flow velocities can be accurately …

Dissociation Quotients Of Malonic Acid In Aqueous Sodium Chloride Media To 100°C1, Richard Kettler, David J. Wesolowski, Donald A. Palmer

Department of Earth and Atmospheric Sciences: Faculty Publications

The first and second molal dissociation quotients of malonic acid were measured potentiometrically in a concentration cell fitted with hydrogen electrodes. The hydrogen ion molality of malonic acidJbimalonate solutions was measured relative to a standard aqueous HCI solution from 0 to 100°C over 25° intervals at five ionic strengths ranging from 0.1 to 5.0 molal (NaCl). The molal dissociation quotients and available literature data were treated in the all anionic form by a seven-term equation. This treatment yielded the following thermodynamic quantities for the first acid dissociation equilibrium at 25°C: log K_1a = -2.852 ± 0.003. ΔH_1̊a = …

Paleontology Of The Cretaceous Of The Central Kerguelen Plateau, David K. Watkins, Patrick G. Quilty, Barbara A.R. Mohr, Shaozhi Mao, J. E. Francis, Carole T. Gee, Millard F. Coffin

Department of Earth and Atmospheric Sciences: Faculty Publications

A synthesis of the Cretaceous calcareous nannofossil, foraminifer, terrestrial and marine palynomorph, macrofauna, and macroflora data from drill sites on the Central Kerguelen Plateau indicates a complex sedimentary history spanning the Albian through the Maestrichtian. Nonmarine Albian sediments from the eastern part of the central plateau record the initial colonization and subsequent succession of plant communities on the basaltic islands left by edifice-building events during the Early Cretaceous. The eastern and northern parts of the central plateau foundered during the early Late Cretaceous. Disconformity-bounded sequences of pelagic calcareous sediment accumulated there throughout the Cenomanian to early Campanian. Following a widespread …

Upper Cretaceous Nannofossils From Leg 120, Kerguelen Plateau, Southern Ocean, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

Drilling on the Kerguelen Plateau during Leg 120 cored the most complete, best preserved record of the Late Cretaceous of the Southern Ocean to date. Two calcareous pelagic sedimentary sections (Sites 747 and 750) provide a record from the upper Turonian(?)-lower Coniacian through the Maestrichtian. Two major disconformities interrupt the record: upper Coniacian-lower Santonian and mid-Campanian. Site 748 contains a Campanian-Maestrichtian record of neritic sedimentation dominated by nannofossil-bearing, intermittently silicified, glauconitic bioclastic grainstones to wackestones. Parts of the upper Maestrichtian and the mid-Campanian are absent at this site.

A set of 21 biostratigraphic events were used to correlate these sections. …

Biogeography Of Campanian-Maastrichtian Calcareous Plankton In The Region Of The Southern Ocean: Paleogeographic And Paleoclimatic Implications, Brian T. Huber, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

Analysis of biogeographic distribution patterns among Campanian-Maastrichtian calcareous nannoplankton and planktonic foraminifera from the southern high latitudes provides insight to changes in circum-Antarctic climate and surface circulation surface routes. Both microfossil groups are similarly characterized in the early Campanian by low-diversity, cosmopolitan species with few or no austral provincial taxa. This changes by late Campanian-early Maastrichtian time as austral species diversified and began to dominate the high-latitude assemblages. Maximum diversity of austral provincial taxa occurs during the late Campanian among the planktonic foraminifera and in the early Maastrichtian among the calcareous nannoplankton. Climatic cooling is considered the cause for the …

9. Composition And Origin Of Cr-Rich Glauconitic Sediments From The Southern Kerguelen Plateus (Site 748), Peter Rene Bitschene, Mary Anne Holmes, James Brezza

Department of Earth and Atmospheric Sciences: Faculty Publications

Five hundred meters of a unique Upper Cretaceous Cr-rich glauconitic sequence (Unit III) that overlies a 3-m-thick alkali-basalt flow with underlying epiclastic volcanogenic sediments was drilled at ODP Leg 120 Site 748. The Cr-rich glauconitic sequence is lithostratigraphically and biostratigraphically divided into three subunits (IIIA, IIIB, IIIC) that can also be recognized by the Cr concentration of the bulk sediment, which is low (<200 ppm) in Subunits IIIC and IIIA and high (400-800 ppm) in Subunit IIIB. The Cr enrichment is caused by Cr-spinel, which is the only significant heavy mineral component beside Fe-Ti ores. Other Cr-bearing components are glauconite pellets and possibly some other clay minerals.
The glauconitic sequence of Subunit IIIB was formed by reworking of glauconite and volcanogenic components that were transported restricted distances and redeposited downslope by mass-transportation processes. The site of formation was a nearshore, shallow inner shelf …

Ages Of The Whitewater And Fairhaven Tills In Southwestern Ohio And Southeastern Indiana, Barry B. Miller, William D. Mccoy, William J. Wayne, C. Scott Brockman

Department of Earth and Atmospheric Sciences: Faculty Publications

Alloisoleucine/isoleucine (aIle/Ile) ratios obtained from fossil mollusc shells collected at localities in southwestern Ohio and southeastern Indiana, where they occur in silt beds associated with the Whitewater and Fairhaven tills, indicate a pre-Wisconsinan age for these tills, which had previously been thought to be early or middle Wisconsinan.

The aIle/Ile ratios in shells from beneath the buried soil (Sidney soil) and till exposed near Sidney, Ohio, are most similar to values in shells obtained from Illinoian sediments at Clough Creek in Hamilton County, Ohio; Mechanicsburg southwest, Illinois; and Trousdale Mine in Vermillion Co., Indiana. The first well-developed weathering profile in …

8. Cretaceous Subtropical Weathering Followed By Cooling At 60°S Latitude: The Mineral Composition Of Southern Kerguelen Plateau Sediment, Leg 120, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

Kaolinite, goethite, minor hematite, and gibbsite were found in fluvial upper Lower Cretaceous basal sediment from the Southern Kerguelen Plateau, Sites 748 and 750, 55°S latitude. This mineral assemblage, derived from the weathering of basalt, indicates near-tropical weathering conditions with high orographic rainfall, at least 100 cm per year. The climate deteriorated by the Turonian or Coniacian, as indicated by the decline in kaolinite content of this sediment.
The Upper Cretaceous sediment at Site 748 consists of 200 m of millimeter-laminated, sparsely fossiliferous, wood-bearing glauconitic siltstone and clay stone with siderite concretions deposited on a shelf below wave base. Some …

Hallazgo De Gasterópodos En La Formación Sijes (Mioceno Superior) Salta, República Argentina, R. N. Alonso, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Se da a conocer el hallazgo de gasterópodos en una secuencia sedimentaria continental rica en evaporistas y muy pobre en fósiles. Los gasterópodos fueron descubiertos en capas tufáceas, diatomíticas, del Miembro Esperanza de la Formación Sijes, de edad Mioceno superior. El análisis taxonómico permitió ubicarlos como pertenecientes a una nueva especie del género Littoridina. La sección sedimentaria, de origen lacustre tipo playa-lake, contiene mineralizaciones económicas de boratos que son minadas actualmente. La presencia de estos gasterópodos fósiles tiene importancia desde el punto de vista ambiental y son aquí utilizados en la interpretación sobre la génesis de los boratos.

The …