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F.A. Welder

Publications and source records attributed to F.A. Welder.

7 recordsLinked to original sources
USGS1971

Ground-water reconnaissance of selected sites in Rocky Mountain National Park and Shadow Mountain National Recreation area, Colorado

An evaluation of the ground-water supply potential at 30 sites within the Rocky Mountain National Park and Shadow Mountain National Recreation Area was made by the U.S. Geological Survey in 1967 and 1968. The work consisted of a geohydrologic reconnaissance, well inventory, and test drilling. The study sites are underlain by. Precambrian crystalline rocks, Tertiary sediments, or Quaternary glacial and alluvial deposits. The crystalline rocks are generally poor aquifers; however, some wells intercepting fractures may yield as much as 10 gallons per minute from wells 100 to 200 feet deep. Wells drilled in Tertiary sandstones to a depth of 50 to 500 feet may supply 1 to 50 gallons per minute. Wells drilled in unconsolidated glacial and alluvial deposits of Quaternary age yield the largest supplies of ground water in the Rocky Mountain National Park. These deposits commonly can supply 5 to 100 gallons per minute to wells.

Open-File Report↗
USGS1967

Preliminary report on Bureau of Mines Yellow Creek core hole No. 1, Rio Blanco County, Colorado

Analysis of geologic, hydrologic , and geophysical data obtained in and around Yellow Creek core hole No. 1, Rio Blanco County, Colorado, indicate a 1,615-foot section of oil shale was penetrated by the hole. Geophysical log data indicate the presence of 25 gallons per ton shale for a thickness of 500 feet my be marginal. The richest section of oil shale is indicated to be centered around a depth of 2,260 feet. Within the oil shale the interval 1,182 to 1,737 feet is indicated to be relatively structurally incompetent and probably permeable. Extension of available regional hydrologic data indicate the oil shale section is probably water bearing and may yield as much as 1,000 gallons per minute. Hydrologic testing in the hole is recommended.

Open-File Report↗
USGS1967

Preliminary report on the geology, geophysics and hydrology of USBM/AEC Colorado core hole No. 2, Piceance Creek Basin, Rio Blanco County, Colorado

Approximately 1,400 feet of continuous core was taken .between 800-2,214 feet in depth from USBM/AEC Colorado core hole No. 2. The drill, site is located in the Piceance Creek basin, Rio Blanco County, Colorado. From ground surface the drill hole penetrated 1,120 feet of the Evacuation Creek Member and 1,094 feet of oil shale in the Parachute Creek Member of the Green River Formation. Oil shale yielding more than 20 gallons per ton occurs between 1,260-2,214 feet in depth. A gas explosion near the bottom of the hole resulted in abandonment of the exploratory hole which was still in oil shale. The top of the nahcolite zone is at 1,693 feet. Below this depth the core contains common to abundant amounts of sodium bicarbonate salt intermixed with oil shale. The core is divided into seven structural zones that reflect changes in joint intensity, core loss and broken core due to natural causes. The zone of poor core recovery is in the Interval between 1,300-1,450 feet. Results of preliminary geophysical log analyses indicate that oil yields determined by Fischer assay compare favorably with yields determined by geophysical log analyses. There is strong evidence that analyses of complete core data from Colorado core holes No. 1 and No. 2 reveal a reliable relationship between geophysical log response and oil yield. The quality of the logs is poor in the rich shale section and the possibility of repeating the logging program should be considered. Observations during drilling, coring, and hydrologic testing of USBM/AEC Colorado core hole No. 2 reveal that the Parachute Creek Member of the Green River Formation is the principal aquifer water in the Parachute Creek Member is under artesian pressure. The upper part of the aquifer has a higher hydrostatic head than, and is hydrologically separated from the lower part of the aquifer. The transmissibility of the aquifer is about 3500 gpd per foot. The maximum water yield of the core hole during testing was about 500 gpm. Chemical analyses of water samples indicate that the content of dissolved solids is low, the principal ions being sodium and bicarbonate. Although the hole was originally cored, to a depth of 2,214 feet, ,the present depth is about 2,100 feet. This report presents a preliminary evaluation of core examination, geophysical log interpretation and hydrological tests from the USBM/AEC Colorado core hole No. 2. The cooperation of the U.S. Bureau of Mines is gratefully acknowledged. The reader is referred to Carroll and others (1967) for comparison of USBM/AEC Col0rado core hole No. 1 with USBM/AEC Colorado core hole No. 2.

Open-File Report↗
USGS1964

Geology and ground-water resources of Uvalde County, Texas

The principal aquifer in Uvalde County is the Edwards and associated limestones of Cretaceous age. The aquifer underlies an extensive area in south-central Texas extending along the Balcones fault zone from Kinney County eastward to San Antonio, and thence northeastward to Hays County. The hydrologic unit making up the Edwards and associated limestones consists of the Comanche Peak limestone, the Edwards limestone, the Kiamichi formation, and the Georgetown limestone. Other less important aquifers in Uvalde County include the Glen Rose limestone, the Buda limestone, the Austin chalk, and the Leona formation. Uvalde County occupies parts of two physiographic provinces, the Edwards Plateau on the north and the Coastal Plain on the south; the two provinces are separated by the Balcones fault zone. In the Edwards Plateau the formations of the Edwards and associated limestones crop out on the plateau surface; in the Coastal Plain where the formations have been down-faulted, they underlie younger rocks. In both provinces the formations dip gently toward the south and southeast; the dips are greatest in the Coastal Plain. Igneous intrusions have penetrated the formations in many places in the Coastal Plain, and locally have formed barriers to ground-water movement. The aquifers in Uvalde County are recharged by precipitation within the county and in the drainage areas of streams entering the county from the north and west. In the Edwards Plateau, the Edwards and associated limestones are recharged by precipitation that falls on the outcrop. The aquifer is drained by springs at the contact with the underlying Glen Rose limestone where streams have cut through the Edwards at the edge of the plateau. These springs maintain the base flow of the streams that drain the plateau. Most of the base flow and much of flood flow of the streams is lost to the Edwards and associated limestones where they crop out in streambeds in the Balcones fault zone. This stream loss to the aquifer constitutes the greatest part of the recharge in the county, although some of the recharge from the West Nueces River enters the county as underflow from Kinney County. The normal annual recharge to the Edwards in Uvalde County is estimated to be about 200,000 acre-feet. Discharge from the Edwards and associated limestones in Uvalde County can be divided into two .major segments: discharge by underflow from the county to the east and south and discharge to the surface through wells and springs. Discharge by underflow during the period 1934-47, when changes in storage were small, is estimated to have been about 190,000 acre-feet per year. During the drought years 1947-56 the underflow was somewhat less. The discharge to the surface during 1934-47 averaged about 17,000 acre-feet per year. During the 1947-56 drought the rate of discharge to the surface increased principally because of increased use of water for irrigation, reaching a maximum of 58,000 acre-feet in 1956. The chemical quality. of the ground water in Uvalde County ranges between wide limits. Except in the extreme southern part of the county where the water is saline, the water in the Edwards and associated limestones is of good chemical quality except that it is hard. The water in the Glen Rose limestone is saline in many places; the principal objectionable constituents are high concentrations of calcium and magnesium sulfate. The water in the Leona formation is generally of good chemical quality. The water from the other formations varies widely in quality from place to place and no generalizations can be made. Ground-water withdrawals from the Edwards and associated limestones in Uvalde County probably could be maintained indefinitely at a rate of about 200,000 acre-feet per year, provided that withdrawals north and west of the county were not increased. However, continued withdrawals at this rate-would cause wells in structurally high areas to go dry, and underflow into Medina County would cease. Furthermore, saline water might invade the fresh-water part of the aquifer from the south, and perennial spring flow in the Leona River valley would cease.

Texas↗