Geology topics

M.E. Dorsey

Publications and source records attributed to M.E. Dorsey.

12 recordsLinked to original sources

USGS1990

Guidelines for collection and field analysis of water-quality samples from streams in Texas

This manual provides standardized guidelines and quality-control procedures for the collection and preservation of water-quality samples and defines procedures for making field analyses of unstable constituents or properties. Descriptions and procedures are given for several methods of sampling for which a variety of samplers may be used. Sample-processing devices such as sample churns and filtration apparatus are discussed along with methods of cleaning. Analyses for unstable constituents or properties are by necessity performed in the field. This manual addresses analytical techniques and quality assurance for: (1) Water temperature; (2) specific conductance; (3) pH; (4) alkalinity; (5) dissolved oxygen; and (6) bacteria.

Texas↗

USGS1989

Summary of hydrologic data for the San Gabriel River basin and Edwards Aquifer, Georgetown area, Texas, water year 1988

The Edwards aquifer is the principle source of freshwater for municipal, domestic, and industrial users in the Georgetown area. Other sources of freshwater are the streams draining the San Gabriel River basin and Lake Georgetown. Lake Georgetown, located on the North Fork San Gabriel River west of Georgetown, is a freshwater supply for some municipalities in the area, water in the San Gabriel River basin also supplies a variety of needs east of Georgetown. Because of the importance of the Edwards aquifer and the surface waters in the area, the U.S. Geological Survey, in cooperation with the city of Georgetown, conducted a monitoring program of the Edwards Aquifer and principal streams during water year 1988. The study area centered on Georgetown and encompassed an area of about 150 square miles (fig. 1). The freshwater resources in the Georgetown area have been the subject of three recent reports. Baker and others (1986) described the Edwards aquifer and the relation between recharge and discharge. Krietier and others (1987) provided fracture analysis, geologic mapping, ground-water chemistry, and the relation between rainfall and recharge in the study area. Land and Dorsey (1988) conducted an investigation to reassess the inclusion of the Georgetown Limestone as one of the geologic units comprising the Edwards aquifer. In addition, the Geological Survey publishes streamflow and water-quality data in the Water Resources Data for Texas report on an annual basis. The primary purpose of this report is to present a summary of the hydrologic data collected from the streams draining the San Gabriel River basin and from the Edwards aquifer during the 1988 water year (October 1987–September 1988). A secondary purpose is to add perspective to the 1988 data by including data from the previous 2 years (1986 and 1987) when available. The scope of the report is limited to the Georgetown area (fig. 1) and to data collected by the Geological Survey.

Texas↗

USGS1988

Reassessment of the Georgetown limestone as a hydrogeologic unit of the Edwards Aquifer, Georgetown area, Texas

The Edwards aquifer consists of geologic units known as the Comanche Peak (oldest) and Edwards Limestones, Kiamichi Formation, and Georgetown Limestone. The Edwards Limestone is the main water-bearing zone. The shallow geologic units dip to the east-southeast at a slope of 50 to 100 feet per mile in the Georgetown area. The Edwards aquifer extends from the western limits of the outcrop to the transition zone from freshwater to saline water to the east. The downdip continuity of the geologic units is interrupted by several faults in the Balcones fault zone. The aquifer is recharged by the infiltration of precipitation and streamflow in the outcrop and is discharged by springs in the outcrop and by wells, evapotranspiration, and leakage through the overlying confining bed in the confined area. Streams in the area regionally flow from the west to the east. A reassessment of the uppermost geologic unit of the Edwards aquifer, the Georgetown Limestone, was conducted in the Georgetown area, Texas, using: (1) data from six surveys of streamflow gains and losses and ground-water levels, (2) aquifer tests at three clusters of test wells, (3) variation in water-quality characteristics to indicate ground-water circulation, and (4) previous studies. Data from the six surveys did not show a pattern of corresponding streamflow gains and losses with positive (upward) and negative (downward) head differentials, respectively, between the main water-bearing zone of the Edwards aquifer and the streams. A consistent and corresponding pattern was shown only for the subreach containing Berry Springs. The aquifer tests consisted of "slug" test analyses to determine the transmissive characteristics of the Georgetown Limestone and produced 8 9 hydraulic conductivity values ranging from 1.4 X 10 -8 to 2.8 X 10 -9 centimeters per second at four of the six test wells. The other two test wells did not produce data suitable for conventional aquifer-test analysis. An analysis of the water-quality characteristics suggests that the Edwards Limestone and the streams have a significant hydraulic connection but the ground-water circulation between the Edwards Limestone and the Georgetown Limestone is very limited. The only area where a high degree of hydraulic connection between the main water-bearing zone of the Edwards aquifer (Edwards Limestone) and the streams was found is near the updip limits of the Georgetown Limestone, where a nearby major fault occurs and where major springs have developed. These findings suggest that the Georgetown Limestone does not function as a unit of the Edwards aquifer but as a regional confining bed with localized avenues that allow flow to and from the underlying Edwards aquifer.

Water-Resources Investigations Report↗

USGS1987

Hydrologic data for urban studies in the Austin metropolitan area, Texas, 1985

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. Studies are now in progress in Austin, and Houston. Studies have been completed in the Dallas, Fort Worth, and San Antonio areas. The Geological Survey, in cooperation with the Texas Department of Water Reources, began hydrologic studies in the Austin urban area in 1954. In cooperation with the city of Austin, the program was expanded in 1975 to include additional streamflow and rainfall gaging stations, and the collection of surface water-quality data. In 1978, the program was expanded to include a ground-water resources study of the South Austin metropolitan area in the Balcones Fault Zone. The objectives of the Austin 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 determine the variations in water quality during different seasons and flow conditions in representative watersheds with various types of urban development. To quantitatively appraise the ground-water resources of the Edwards aquifer in hydraulic circulation with Barton Springs, the effect of urbanization on the quality and quantity of recharge and discharge, and the extent of contamination in the aquifer. This report presents the basic hydrologic data collected in the Austin urban area for the 1985 water year (Oct. 1, 1984 to Sept. 30, 1985). Additional explanations of terms related to streamflow, water quality, and other hydrologic data used in this report are defined in the U.S. Geological Survey annual report Water Resources Data for Texas, TX-85-3, 1985.

Texas↗

USGS1987

Hydrologic and geologic data for the Edwards Aquifer Recharge Zone near Georgetown, Williamson County, Texas, 1986-87

This report presents a compilation and summary of data related to the interchange of water between the Edwards aquifer and streams, and to the hydraulics of vertical movement of water in the Georgetown Limestone in the Georgetown area of Williamson County. It presents hydrologic, geologic, hydraulic, physical, geophysical, and water-quality data collected from selected wells and stream sites in the study area from January 1986 to June 1987. Included are the results from six streamflow gain and loss surveys, two ground-water-level surveys representing low and high water-level conditions, inorganic chemical analyses of water from selected wells and streams, and bulk specific gravity and permeability tests of cores taken at three test-well sites. Water-level altitudes differed by an average of 38 feet between low and high water-level conditions in the confined zone, and by an average of 13 feet in the unconfined zone. Dissolved solids of water from selected wells ranged from 320 to 1,300 milligrams per liter and from 251 to 290 milligrams per liter in water from selected streams.

Open-File Report↗

USGS1986

Hydrologic data for urban studies in the Austin metropolitan area, Texas, 1984

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. Studies are now in progress in Austin, and Houston. Studies have been completed in the Dallas, Fort Worth, and San Antonio areas. The Geological Survey, in cooperation with the Texas Department of Water Reources, began hydrologic studies in the Austin urban area in 1954. In cooperation with the city of Austin, the program was expanded in 1975 to include additional streamflow and rainfall gaging stations, and the collection of surface water-quality data. In 1978, the program was expanded to include a ground-water resources study of the South Austin metropolitan area in the Balcones Fault Zone. The objectives of the Austin 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 determine the variations in water quality during different seasons and flow conditions in representative watersheds with various types of urban development. To quantitatively appraise the ground-water resources of the Edwards aquifer in hydraulic circulation with Barton Springs, the effect of urbanization on the quality and quantity of recharge and discharge, and the extent of contamination in the aquifer. This report presents the basic hydrologic data collected in the Austin urban area for the 1984 water year (Oct. 1, 1983 to Sept. 30, 1984). Additional explanations of terms related to streamflow, water quality, and other hydrologic data used in this report are defined in the U.S. Geological Survey annual report Water Resources Data for Texas, TX-84-3, 1984.

Texas↗

USGS1985

Hydrologic data for urban studies in the Austin, Texas, metropolitan area, 1983

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. Studies are now in progress in Austin, and Houston. Studies have been completed in the Dallas, Fort Worth, and San Antonio areas. The Geological Survey, in cooperation with the Texas Department of Water Reources, began hydrologic studies in the Austin urban area in 1954. In cooperation with the city of Austin, the program was expanded in 1975 to include additional streamflow and rainfall gaging stations, and the collection of surface water-quality data. In 1978, the program was expanded to include a ground-water resources study of the South Austin metropolitan area in the Balcones Fault Zone. The objectives of the Austin 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 determine the variations in water quality during different seasons and flow conditions in representative watersheds under various types of urban development. To quantitatively appraise the ground-water resources along the Balcones Fault Zone, the effect of urbanization on the quality and quantity of recharge and discharge, and the extent of contamination in the Edwards aquifer that is in hydrologic circulation with Barton Springs. This report presents the basic hydrologic data collected in the Austin urban area for the 1983 water year (Oct. 1, 1982 to Sept. 30, 1983). Additional explanations of terms related to streamflow, water quality, and other hydrologic data used in this report are defined in the U.S. Geological Survey annual report Water Resources Data for Texas, TX-83-3, 1983.

Texas↗

USGS1984

Geohydrology of the Edwards Aquifer in the Austin area, Texas

No abstract available.

Texas↗

USGS1982

Hydrologic data for urban studies in the Austin, Texas, metropolitan area, 1980

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. Studies are now in progress in Austin, Houston, and San Antonio. Studies have been completed in the Dallas and Fort Worth areas. The Geological Survey, in cooperation with the Texas Department of Water Resources, began hydrologic studies in the Austin urban area in 1954. In cooperation with the city of Austin, the program was expanded in 1975 to include additional streamflow and rainfall gaging stations, and the collection of surface water-quality data. In 1978, the program was expanded to include a ground-water resources study of the South Austin metropolitan area in the Balcones fault zone. The objectives of the Austin 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 determine the variations in water quality during different seasons and flow conditions in representatives watersheds under various types of urban development. To quantitatively appraise the ground-water resources along the Balcones fault zone, the effect of urbanization on the quality and quantity of recharge and discharge, and the extent of contamination in the Edwards aquifer that is is hydrologic circulation with Barton Springs. This report presents the basic hydrologic data collected in the Austin urban area for the 1980 water year (Oct. 1, 1979 to Sept. 30, 1980). Additional explanations of terms related to streamflow, water quality, and other hydrologic data used in this report are defined in the U.S. Geological Survey annual report Water Resources Data for Texas, TX-80-3, 1980.

Texas↗

USGS1981

Hydrologic data for urban studies in the Austin, Texas, metropolitan area, 1979

Texas↗

USGS1980

Hydrologic data for urban studies in the Austin, Texas metropolitan area, 1978

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, Dallas County, Fort Worth, Houston, and San Antonio. The Geological Survey, in cooperation with the Texas Department of Water Resources, began hydrologic studies in the Austin urban area in 1954. In cooperation with the city of Austin, the program was expanded in 1975 to include additional streamflow and rainfall gaging stations and the collection of water-quality data. In 1978, the program was expanded to include a ground-water resources study of the South Austin metropolitan area in the Balcones Fault Zone.

Texas↗

USGS1979

A radiographic scanning technique for cores

A radiographic scanning technique (RST) can produce single continuous radiographs of cores or core sections up to 1.5 m long and up to 30 cm wide. Changing a portable industrial X-ray unit from the normal still-shot mode to a scanning mode requires simple, inexpensive, easily constructed, and highly durable equipment. Additional components include a conveyor system, antiscatter cylinder-diaphragm, adjustable sample platform, developing tanks, and a contact printer. Complete cores, half cores, sample slabs or peels may be scanned. Converting the X-ray unit from one mode to another is easy and can be accomplished without the use of special tools. RST provides the investigator with a convenient, continuous, high quality radiograph, saves time and money, and decreases the number of times cores have to be handled.

Marine Geology↗