The upper Ojinaga and San Carlos Formations in the Sierra Vieja region, Presidio County, Texas records the progradation of terrigenous clastic sediments eastward onto the Diablo Platform during Late Cretaceous time. Changes in the relative sea level and strandline position over the platform are documented by six sequences. Two sequences are recognized in the basinal shales of the upper Ojinaga Formation (Oj1 and Oj2): the lower, Sequence Oj1, contains two fossil cold-seep mounds. Sequence Oj2 is terminated by an erosional surface overlain by a thin lag deposit of shells and bored lithoclasts (SHL), which forms the boundary between two formations.

San Carlos Sequence SC1 and Sequence SC2 each consist of a basal SHL, several well-developed parasequences of interbedded shale, silty mudstones, and upward thickening hummock cross-stratified (HMS) sandstones. Sequence SC2 also contains shoreface and tidal deposits. Sequence SC3 consists of alternating marine, coastal and deltaic facies deposited along a fluctuating coastline during the Early Campanian capped by transgressive accumulation of a basal shell horizon and marine shales. The lower boundary of Sequence SC3 is incised, locally cutting down into or through Sequence SC2 into the top of Sequence SC1. Sequence SC3 is followed by a rapid drop of relative sea level in the late Early to Middle Campanian, and the fluvial-deltaic and alluvial plain facies of Sequence SC4 were deposited directly over the deeper-water marine shales

Comparison of the sequence stratigraphy of a transect along the southwestern margin of the Western Interior Cretaceous Basin, between the Sierra Vieja, San Juan Basin, and the Book Cliffs regions, illustrate sequences boundaries and transgressive flooding surfaces are local features and not correlatable over the distance of the transect. The Ojinaga mounds are interpreted to be of a biogenetic origin formed from cold-seep communities surrounding a submarine methane-rich fluid or gas source. Beside the Ojinaga cold-seep mounds, four intervals of cold-seep activity are identified from the Middle through Maastrichtian. Comparison of the fossil cold-seep mound distribution to subsurface structures, Late Cretaceous subsidence patterns, and strandline position, suggest there is an association between cold-seep formation, changes in the tectonics of the WIK basin and forebulge development.

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The Permian (Guadalupian) Grayburg Formation of Means field, Andrews County, Texas, consists of siliciclastic, carbonate and evaporite strata that were deposited in three general platform environments: (1) subtidal open shelf, (2) subtidal to intertidal shallow-shelf, and (3) supratidal coastal flats and sabkhas.

Vertical repetition of lithofacies can be used to identify small-scale shallowing-upward cycles in these strata. These shallowing-upward cycles are related to high-frequency low-amplitude sea-level fluctuations that affected platform sedimentation. The Grayburg composite sequence at Means field is composed of four high-frequency sequences. The lower two high-frequency sequences (HFS 1 and 2) record increased accommodation during long-term transgression, while the upper two (HFS 3 and 4) reflect decreased accommodation during later highstand conditions. Maximum flooding of the shelf occurred during deposition of HFS 2.

The original textural and mineralogical composition of the Grayburg Formation was extensively altered by diagenesis. Early diagenesis resulting from hydrologic processes associated with continued sedimentation of younger strata resulted in replacive dolomitization and anhydrite emplacement. Late diagenesis reflects the influence of regional processes such as increased temperature and pressure, the introduction of meteoric water following Tertiary uplift of the western edge of the Permian Basin, and bacterial sulfate reduction and resulted in the precipitation of calcite, kaolinite, authigenic silica, and pyrite and the development of secondary porosity.

Hydrocarbon production from the Grayburg Formation is generally concentrated in open shelf, shallow shelf, and shoal dolostones and dolomitic sandstones where both depositional (grain type, size and abundance) and diagenetic controls (dolomitization and dissolution) have led to the development of sufficient porosity and permeability for hydrocarbon flow.

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VAN claims of successful earthquake prediction date back to the early 1980s but their method is still controversial, partly because of disagreement on how their Seismic Electric Signal (SES) precursors may be generated or detected far from the focal region. This research involves both aspects of the problem. It shows that Thermally Stimulated (de)Polarization Current (TSPC) experiments previously suggested to support the piezostimulation model for SES generation fail to do so. The anomalous currents produced by Greek rocks and other samples during these experiments are not of piezoelectric origin. Regarding SES detection, the shallow geoelectric section of several sensitive and insensitive VAN stations was surveyed to identify conductive SES pathways. These pathways are required for long distance SES transmission. Schlumberger and time domain electromagnetic soundings revealed none in the upper few hundred meters. Identifying more deeply buried conductive pathways should be the next step taken. Should a deep conductor not be resolvable with confidence research should shift emphasis to local SES generation mechanisms that do not require such pathways.

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This study investigates the surface to subsurface relationship at Longhorn Cavern State Park, which can become one part of an interdisciplinary educational program taught at the park. Longhorn Cavern is located on Backbone Ridge; a wedge shaped topographically high graben, which is bounded by Pennsylvanian age normal faults. The phreatic cavern passages were fully developed by the Pleistocene, and it is currently a shallow (<40 m) dry cavern. The combination of the 1-meter resolution digital orthophoto quadrangles (DOQ’s) with a 1971 topographic map (CI=2ft) yields a map with a 1-meter resolution horizontal scale and a 0.62 m (2-ft) vertical scale. This map provides an accurate representation of the surface in which the karst features can be identified and evaluated. Sinkholes smaller than 15,834 m2 only occur within 150 m of the cavern, creating a recognizable "cavern footprint" on the surface. The clints, grikes, solution pans, rills, and other karren features indicate there was little to no soil cover in the sinkholes within 150 m of the cavern before European settlement in the area. The linear trending cavern passages suggest structural control of the cavern, but the structural data when compared to individual passage trends and individual passage morphology proves lithologic control of Longhorn Cavern with local joint control. Longhorn Cavern trends parallel to subparallel the strike of the Gorman formation in the Ellenburger Group, discharging along the Roaring Springs Fault Zone. Longhorn Cavern provides an excellent opportunity to illustrate for teaching purposes how the convergent and multiple processes work to create a landscape.

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Many of the physical and chemical aspects of an ecological system must be evaluated as part of the design phase of many man-made parks. If these factors are not taken into account, the result may be a park with little aesthetic appeal. One example of this can be found along Wolf Pen Creek in College Station, Texas. There has been little development over the past couple of decades in the Wolf Pen Creek drainage basin and therefore, Wolf Pen Creek is considered to be an urban stream that has maintained a state of quasi-equilibrium. However, a considerable amount of erosion of the stream banks can be found from Wolf Pen’s headwaters to its confluence with Carter Creek in the form of vertical slopes and undercut banks. Prior studies in the College Station area have related the excessive erosion of stream banks to the stage of development within the drainage basin. In other words, previous authors related the hydraulics of the drainage basin to its state of urbanization (undisturbed, urbanizing, or urbanized). However, the state of urbanization is not the controlling factor in the case of Wolf Pen Creek and many other similar urban drainage basins. Instead, the level of stability varies with other factors, namely the geology of the basin and climate in the region. The bank material along Wolf Pen Creek is mostly that of silty and sandy clays. It is thought that the wetting and re-wetting of these dry clays during storm events causes slaking, a process resulting in the physical disaggregation, or crumbling, of clays when submersed in water. As a result, these urban streams that drain fine clastic material have high suspended loads. The process of slaking is believed to be a natural phenomenon in urban stream systems draining fine to very fine clastic material and is therefore, not feasible to manage such systems in ways that other watersheds are. Other approaches must be investigated in the design phase of such projects to make them work. Additionally, many projects may require an on-going maintenance program to be successful.

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