USGS Science⌕ Search

Geology topics

Research about Texas

Source-linked reports with geographic coverage including Texas.

At least 1,189 records · Page 66Linked to original sources
USGS1978

Longitudinal turbidity structures in a bar-built coastal plain estuary, Corpus Christi Bay, Texas

Corpus Christi Bay is a shallow, bar-built variety of estuary that is characteristic of the South Texas Coastal Plain. On the basis of synoptic in situ measurements of light transmissivity and suspended-sediment concentrations at six monitoring stations, a time sequence of six turbidity structures was established along the longitudinal trend of the bay and its tidal inlet over a 16-month observation period. The bay turbidity structures were observed to be highly variable in time and space. Structures ranged from a vertically homogeneous water column, to a well-stratified column exhibiting an increasing turbidity gradient with depth. Wind appeared to be the dominant forcing agent influencing turbidity toward the bayhead sector, where it both generates waves for bottom-sediment resuspension and regulates fluvial sediment influx from the Nueces River. Turbidity toward the baymouth sector appeared to be dominantly regulated by tidal forcing effects from Aransas Pass inlet. Both the discharge characteristics of the Nueces River and the mean density of the bay's water column had no discernible influence on the observed bay turbidity structures.

Texas↗
USGS1978

Sediment yields for selected streams in Texas

The U.S. Geological Survey began a study to determine sediment yields for selected streams in Texas during the 1966 water year to provide information for areas in which sediment-yield data were meager or lacking. These data will aid in delineating problem areas and planning for water-resources development in the State. This report presents estimates of suspended-sediment loads and yields from 20 drainage basins ranging in area from 26 to 1,410 square miles. These estimates are based on samples collected periodically during water years 1966-74. Sediment loads ranged from 1,500 tons per year at the station North Fork Hubbard Creek near Albany to 278,000 tons per year at the station Wichita River at Wichita Falls. Sediment yields ranged from 15 tons per square mile per year in the drainage area of East Yegua Creek near Dime Box to 500 tons per square mile per year in the drainage area of Denton Creek near Justin. Sediment yields from drainage areas generally decrease from northwest to southeast across the State.

Texas↗
USGS1978

Method of estimating natural recharge to the Edwards Aquifer in the San Antonio area, Texas

The method of estimating annual recharge is based on data collected from a network of stream-gaging stations and on assumptions related to applying the runoff characteristics from gaged areas to ungaged areas. The basic approach is a water-balance equation, in which recharge within a stream basin is the difference between measured streamflow above and below the infiltration area of the aquifer plus the estimated runoff in the zone that includes the infiltration area. Recharge in the Medina River basin also includes seepage losses from Medina Lake and Diversion Reservoir. The principal errors in the estimates of annual recharge are related to errors in estimating runoff in ungaged areas, which represent about 30 percent of the infiltration area. The estimated long-term average annual recharge in each basin, however, is probably representative of the actual recharge because the averaging procedure tends to cancel out the major errors.

Texas↗
USGS1978

Interpretation of well logs in a carbonate aquifer

This report describes the log analysis of the Randolph and Sabial core holes in the Edwards aquifer in Texas, with particular attention to the principles that can be applied generally to any carbonate system. The geologic and hydrologic data were obtained during the drilling of the two holes, from extensive laboratory analysis of the cores, and from numerous geophysical logs run in the two holes. Some logging methods are inherently superiors to others for the analysis of limestone and dolomite aquifers. Three such systems are the dentistry, neutron, and acoustic-velocity (sonic) logs. Most of the log analysis described here is based on the interpretation of suites of logs from these three systems. In certain instances, deeply focused resistivity logs can be used to good advantage in carbonate rock studies; this technique is used to computer the water resistivity in the Randolph core hole. The rocks penetrated by the Randolph core hole are typical of those carbonates that have undergone very little solution by recent ground-water circulation. There are few large solutional openings; the water is saline; and the rocks are dark, dolomitic, have pore space that is interparticle or intercrystalline, and contain unoxidized organic material. The total porosity of rocks in the saline zone is higher than that of rocks in the fresh-water aquifer; however, the intrinsic permeability is much less in the saline zone because there are fewer large solutional openings. The Sabinal core hole penetrates a carbonate environment that has experienced much solution by ground water during recent geologic time. The rocks have high secondary porosities controlled by sedimentary structures within the rock; the water is fresh; and the dominant rock composition is limestone. The relative percentages of limestone and dolomite, the average matrix (grain) densities of the rock mixtures , and the porosity of the rock mass can be calculated from density, neutron, and acoustic logs. With supporting data from resistivity logs, the formation water quality can be estimated, as well as the relative cementation or tortuosity of the rock. Many of these properties calculated from logs can be verified by analysis of the core available from test holes drilled in the saline and fresh water zones.

Texas↗
USGS1978

A reexamination of the Pennsylvanian trace fossil Olivellites

The original interpretation of Olivellites plummeri Fenton and Fenton as the trace of an infaunal gastropod, is reconsidered and rejected. The original slab bearing several examples of O. plummeri has been reexamined and reillustrated. The slab came from the type-locality of O. plummeri in Eastland County, Tex., and is a shallow sub tidal sandstone of the Graham Formation; the sandstone, which has yielded additional specimens, is presumably a reworked delta-front deposit. Olivellites was also observed in the Caddo Creek Formation in Stephens County, Tex., but, to date, it has not been found elsewhere in north-central Texas. Interpretation of Paleozoic ichnofossils by analogy with modern traces is limited; behavioral characteristics may be the products of post-Paleozoic innovation. The internal morphology and path of Olivellites are unlike those of any modern gastropod trail, and the genus is removed from the Mollusca.

Texas↗
USGS1977

Hydrologic data for North Creek, Trinity River basin, Texas, 1975

This report contains the rainfall, runoff, and storage data collected during the 1975 water year for the 21.6-square-mile area above the stream-gaging station North Creek near Jacksboro, Texas. The weighted-mean rainfall in the study area during the water year was 39.01 inches, which is greater than the 18-year average of 30.21 inches for the period 1958-75. Monthly rainfall totals ranged from 1.04 inches in November to 7.94 inches in May. The mean discharge for 1975 at the stream-gaging station was 5.98 cfs, compared with the 14-year (1957-70) average of 5.75 cfs. The annual runoff from the basin above the stream-gaging station was 4,330 acre-feet or 3.76 inches. Three storms were selected for detailed computations for the 1975 water year. The storms occurred on Oct. 30-31, 1974, May 2, 1975 , and Aug. 26, 1975. Rainfall and discharge were computed on the basis of a refined time breakdown. Patterns of the storms are illustrated by hydrographs and mass curves. A summary of rainfall-runoff data is tabulated. There are five floodwater-retarding structures in the study area. These structures have a total capacity of 4,425 acre-feet below flood-spillway crests and regulate streamflow from 16.3 square miles, or 75 percent of the study area. A summary of the physical data at each of the floodwater-retarding structures is included. (Woodard-USGS)

Texas↗
USGS1977

Hydrologic data for urban studies in the San Antonio, Texas, metropolitan area, 1975

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. These studies are now in progress in Austin, Dallas and Dallas County, Fort Worth, Houston, and San Antonio. The Geological Survey, in cooperation with the Texas Water Development Board, expanded the existing streamflow network in the San Antonio metropolitan area in May 1968 to begin urban hydrology studies in this area. In September 1968, the program was further expanded to include the collection of water-quality data. The objectives of the Sari Antonio urban hydrology study are: To provide data showing the effects of various stages of urbanization on flood discharge and runoff. To provide water-quality data on surface-water runoff from floods of various magnitudes, during all seasons of the year from areas with different types of utilization. Annual publication of the San Antonio urban studies was initiated in 1969.

Texas↗
USGS1977

Hydrologic data for urban studies in the Houston, Texas, metropolitan area, 1975

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. Studies are now in progress in Austin, Dallas and Dallas County, Fort Worth, Houston, and San Antonio. The U.S. Geological Survey, in cooperation with the city of Houston, began studies in the Houston metropolitan area in 1964. The program was expanded in 1968 to include collection of water-quality data. The objectives of the Houston urban hydrology study are as follows: To determine, on the basis of historical data and hydrologic analyses, the magnitude and frequency of flood peaks and flood volume. To determine the effect of urban development on flood peaks and volume. To ascertain the variation in water quality for different flow conditions and different seasons. This report, the twelfth in a series of reports to be published annually, is primarily applicable to objective 2. The report presents the basic hydrologic data collection in the Houston urban area for the 1975 water year (October 1974 to September 1975). A report by Johnson and Sayre (April 1974) utilized records collected from 1965 to 1969 to make a study of the effects of urbanization on floods in the Houston area. The report also summarizes various basin parameters.

Texas↗
USGS1977

Hydrologic data for urban studies in the Dallas, Texas metropolitan area, 1975

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. These studies are now in progress in Austin, Dallas, Dallas County, Fort Worth, Houston, and San Antonio. In August 1961, the Geological Survey in cooperation with the city of Dallas began a program of investigations designed to evaluate hydrologic factors affecting floods on several small streams in Dallas. Through cooperative agreements with the city of Dallas and the Dallas County Department of Public Works, the original program has been expanded to include the greater Dallas metropolitan area.

Texas↗
USGS1977

Background studies for appraising subsidence in the Texas Gulf Coast region

Significant ground movement has accompanied the extraction of large quantities of fluids from the subsurface at many localities. The possibility of both horizontal and vertical ground movement--subsidence, fissuring, growth faulting--in the Gulf Coast region, caused by the withdrawal of large volumes of deep formation fluids, is of major concern. Although widespread subsidence has resulted from intensive pumping of ground water, huge withdrawals from shallow oil and gas fields, and mining of sulfur and salt, little information is available on possible subsidence caused by deep fluid extractions. As far as is known, none of the major fields in the Gulf Coast region has subsided appreciably as a result of deep oil and gas production. Of special concern in this study are field evidence of or specific research regarding subsidence directly related to geopressured-fluid withdrawals. If deep reservoirs have the same general stress-strain characteristics as shallower reservoirs, appreciable subsidence could accompany major extraction of deep fluid. A reconnaissance of the type and extent of background data available for such a subsidence appraisal was made as a first step in investigating the possibility of land subsidence associated with the exploitation of geopressured reservoirs in the Gulf Coast. This study was limited to the Texas Gulf Coast south of the landward boundary of Miocene deposits. Visits were made to offices of Federal and State agencies and industries, to determine the type and extent of data available for interpreting subsidence potential in the Texas Gulf Coast. This report summarizes the findings of this reconnaissance investigation, including the names and agencies of those contacted and the nature and extent of pertinent data available. Although a tremendous amount of basic data is available in governmental and private files, the task of collecting and interpreting these data and the limitations or lack of some types of data, in terms of subsidence prediction, create major problems.

Texas↗
USGS1977

Development of ground water in the Houston District, Texas, 1970-74

Total withdrawals of ground water in the Houston district increased 9 percent from about 488 million gallons per day (21.4 cubic meters per second) in 1970 to about 532 million gallons per day (23.3 cubic meters per second) in 1974. The average annual rate of increase from 1960 to 1969 was about 6.3 percent. During 1970-74, increases in pumpage occurred in the Houston, Katy, and NASA areas; decreases occurred in the Pasadena and Alta Loma areas; and the pumpage in the Baytown-La Porte and Texas City areas remained almost constant. Water levels continued to decline throughout the district during 197074, but the rate of decline generally was not as great as in previous years. The greatest declines in the past several years were in the Houston area, but the center of decline is still in the Pasadena and Baytown-La Porte areas. The decrease in the rate of decline suggests that the aquifers in the Houston district could support the amount of pumping during 1970-74 with little, if any, further decline. Although saltwater encroachment has probably occurred in the district, particularly in Galveston County, no large increases in chloride were measured at the monitoring points.

Texas↗
USGS1977

Thermoluminescence of sand grains around a South Texas roll-type deposit

The termoluminescence of quartz and feldspar grains around a south Texas roll-type deposit was studied to determine whether a systematic variation in such thermoluminescence exists. Measurements of the thermoluminescence were made in the temperature ranges of 100° to 322°C and 315° to 410°C. Neither temperature range yielded data to differentiate between oxidized and reduced rock. The ratio of the lower temperature to the higher temperature thermoluminescence, however, was consistently higher in ore and reduced rock than in oxidized rock. Studies of thermoluminescence may be useful in identifying alteration related to uranium mineralization.

Texas↗