Overpressured Eocene Wilcox sandstones in the Newton County, Texas Sabine Tram field contain water with salinities ranging from 14 to 28 g/L. The solutes appear to fall loosely into three groups. Na, Ca, and Mg follow systematics previously known globally for saline formation waters whereby their concentrations are controlled by fluid-mineral equilibrium. Cl, Br, I, and B are conservatively diluted constituents of some saline endmember that is not solely connate marine. Potassium does not follow any known basinal systematic, and the formation water is supersaturated with respect to SiO2 by an order of magnitude. Meteoric water is not a probable source of fresh water in the production interval. Diluting water is suspected to be produced by illitization, but could in fact be any water low in dissolved constituents. Mass balance calculations indicate that mixing water of marine salinity with shale dehydration water could produce waters with salinities in the range of values seen at Sabine Tram. Isotopic compositions indicate a diagenetic or saline endmember that is depleted in deuterium and enriched in 18O. It is apparent that multiple contributing sources and reactions are progressing simultaneously in the study area. The possibility is proposed here that residence times are likely short, and the concentrations of the solutes represent multiple, sometimes spatially localized, reactions in progress. A downdip, higher temperature source may possibly be contributing constituents to the system. The data set for Sabine Tram provides an extension of knowledge regarding sedimentary basinal chemical systematics, and characterization of one possible endmember in the Gulf of Mexico sedimentary suite of formation water compositions.

The relations between overpressuring, diagenesis, and fluid flow in sedimentary basins are complex and multifaceted. The Matagorda Island 519 field (MI 519), offshore Texas, provides an excellent area for investigating some of these relations. The top of overpressure at MI 519 occurs at a depth of 3.5 to 3.8 km in a Lower Miocene deltaic sequence. On the basis of log-derived lithostratigraphy, the pressure seal does not appear to be lithologic in origin. Geochemical, mineralogical, and cuttings information indicate instead that the precipitation of diagenetic calcite and possibly quartz cements has been the major factor in seal development. Stratigraphic variation in mudstone chemistry indicates diagenesis has been an open-system process, with significant loss of Ca, Si, Mg, and Fe and gain of K in sediments below the pressure seal. Fluid pressures calculated from shale resistivities provide evidence for several vertically-stacked overpressured compartments at MI 519. Lateral sealing within the overpressured section may be provided by faults and precipitation of diagenetic cements within faults. In contrast to other areas of the Gulf of Mexico Basin, overpressure development at MI 519 does not appear to be due to compaction disequilibrium because of the lack of significant post-Miocene deposition and a lack of a reversal in mudstone porosity below the top of overpressure. More likely causes of overpressuring are clay mineral dewatering, petroleum generation, and the presence of a large column of natural gas. At least six stages of fluid flow and/or diagenetic development have occurred at the field: 1) calcite cementation within preferred intervals from fluids that originated by dissolution of updip salt domes, 2) deep overpressure development and upward focused flow of underlying Mesozoic brines and the development of secondary porosity in reservoir beds by carbonate dissolution, 3) precipitation of a seal by mixing of deeply-sourced and updip-sourced fluids, 4) hydrocarbon generation and shallow overpressure development, with hydrocarbons filling in porosity created by calcite dissolution, 5) hard overpressure development from smectite dehydration, and 6) development of a shallow freshwater lens during the Pleistocene lowstand.

Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution Joint Program in Oceanography/Applied Ocean Science and Engineering, 2001. / "Funding was provided by the National Science Foundation through Contract No. OCE-9300450 and by the Joint Oceanographic Institutions through Subcontract No. JSCI-00." Includes bibliographical references.

Thesis (M.S.)--Texas A & M University, 2003. / "Major Subject: Geophysics." Title from author supplied metadata. Includes bibliographical references.

Thesis (MS)--Texas A & M University, 2002. / Adobe PDF with 90 leaves. "Major Subject: Geophysics." Includes bibliographical references.

Thesis (MS)--Texas A & M University, 2002. / Adobe PDF with 85 leaves. "Major Subject: Geophysics." Includes bibliographical references.

Thesis (MS)--Texas A & M University, 2002. / Adobe PDF with 91 leaves. "Major Subject: Geophysics." Includes bibliographical references.

Thesis (Ph. D.)--Texas A & M University, 2003. / "Major Subject: Geophysics." Title from author supplied metadata. Includes bibliographical references.

Thesis (M.S.)--Texas A & M University, 2003. / "Major Subject: Geophysics." Title from author supplied metadata. Includes bibliographical references.

<p> I conducted geophysical and archaeological investigations on O'ahu Island, Hawai'i alongside the University of Hawai'i Kualoa Field School. Previous research identified Polynesian colonization of the Hawaiian Islands occurring simultaneously with the accretion of Kualoa peninsula. Because of this we conducted investigations north of the peninsula in an attempt to research initial colonization. Previous archaeological excavations used a sampling strategy that resulted in discontinuous evidence with a lack of knowledge about site architecture and settlement expansion prior to and during peninsula accretion. We employed Ground Penetrating Radar (GPR) to perform a continuous subsurface survey over a large area with minimal cost to the environment and labor. GPR identified an anomaly on the northern Kualoa coast that we subsequently excavated and identified as a possible structural complex. It appears and is likely that there was some kind of extension from Kualoa peninsula to the northern Kualoa coastal plain. It seems logical that the northern Kualoa coast was occupied before the southern peninsula stabilized and as the peninsula grew south occupation followed.</p>