Geology topics
Publications and source records attributed to D. E. White.
This dataset contains contacts, geologic units, and map boundaries from Miscellaneous Investigations Series Map I-1371, "The Geologic map of upper Geyser Basin, Yellowstone, National Park, Wyoming". This dataset was constructed to produce a digital geologic map as a basis for ongoing studies of hydrothermal processes.
Parícutin's volcanic activity during its first year of life included a number of periods characterized by flowing lava. The length of time of individual periods ranged from a few days up to more than a month, and were separated by intervals during which little or no lava flowed at the surface. A cyclic activity is therefore obvious, and a more or less permanent record remains in the form of the lava‐flows. The complete cycle, however, is believed to consist essentially of four stages: (1) Flowing lava; (2) maximum gas activity from the central crater (without flow); (3) the rise of lava in the vent; (4) breaching of the cone in preparation for renewed flow.
The potential to use ice cores from alpine glaciers in the midlatitudes to reconstruct paleoclimatic records has not been widely recognized. Although excellent paleoclimatic records exist for the polar regions, paleoclimatic ice core records are not common from midlatitude locations. An ice core removed from the Upper Fremont Glacier in Wyoming provides evidence for abrupt climate change during the mid-1800s. Volcanic events (Krakatau and Tambora) identified from electrical conductivity measurements (ECM) and isotopic and chemical data from the Upper Fremont Glacier were reexamined to confirm and refine previous chronological estimates of the ice core. At a depth of 152 m the refined age-depth profile shows good agreement (1736 ± 10 A.D.) with the 14C age date (1729 ± 95 A.D.). The δ 18 O profile of the Upper Fremont Glacier (UFG) ice core indicates a change in climate known as the Little Ice Age (LIA). However, the sampling interval for δ 18 O is sufficiently large (20 cm) such that it is difficult to pinpoint the LIA termination on the basis of δ 18 O data alone. Other research has shown that changes in the δ18O variance are generally coincident with changes in ECM variance. The ECM data set contains over 125,000 data points at a resolution of 1 data point per millimeter of ice core. A 999-point running average of the ECM data set and results from f tests indicates that the variance of the ECM data decreases significantly at about 108 m. At this depth, the age-depth profile predicts an age of 1845 A.D. Results indicate the termination of the LIA was abrupt with a major climatic shift to warmer temperatures around 1845 A.D. and continuing to present day. Prediction limits (error bars) calculated for the profile ages are ±10 years (90% confidence level). Thus a conservative estimate for the time taken to complete the LIA climatic shift to present-day climate is about 10 years, suggesting the LIA termination in alpine regions of central North America may have occurred on a relatively short (decadal) timescale. Copyright 2000 by the American Geophysical Union.
The availability of fresh ground water in El Paso and adjacent areas that is needed to meet increased demand for water supply concerns local, State, and Federal agencies. The Hueco bolson is the principal aquifer in the El Paso area. Starting in the early 1900s and continuing to the 1950s, most of the municipal and industrial water supply in El Paso was pumped from the Hueco bolson aquifer from wells in and near the Rio Grande Valley and the international border. The Rio Grande is the principal surface-water feature in the El Paso area, and a major source of recharge to the shallow aquifer (Rio Grande alluvium) within the study area is leakage of flow from the Rio Grande. The shallow aquifer and the underlying Hueco bolson aquifer are in general hydrologic connection, but wells that penetrate these aquifers have different water levels and water quality. The configuration (slope) of the predevelopment (pre- 1903) water table indicates that ground water in the Hueco bolson flowed south from the Texas-New Mexico State line toward the El Paso Valley and the Rio Grande. There the water moved upward from the Hueco bolson fill through the alluvium and discharged as seepage at the land surface or through evapotranspiration on the river flood plain. Subsequent (post-January 1903) development of the Hueco bolson has caused water levels to decline in both the bolson aquifer and the shallow aquifer, and these declines have reversed the original vertical hydraulic gradient and now cause vertical leak- 1 Hydrologist, U.S. Geological Survey. 2 Geologist, El Paso Water Utilities-Public Service Board. age downward. Water-level declines in the shallow aquifer have in turn induced increasing amounts of leakage from the Rio Grande and from irrigation canals. The reversal from upward to downward in vertical hydraulic gradient between the Rio Grande alluvium and the underlying Hueco bolson aquifer has induced shallow water in the alluvium to move downward into the deeper aquifer. The introduction of water from the alluvium probably has led to a gradual water-quality deterioration of ground water in the Hueco bolson aquifer. The extent of any deterioration is a major concern because the dissolved solids concentration in water from some wells is approaching 1,000 milligrams per liter and already has exceeded this limit in other wells.
No abstract available.
No abstract available.
Pumping and injection tests were conducted during a 1981-83 pilot study of the Hueco bolson recharge project in northeast El Paso. Water-level decline and buildup were measured in a recharge well and an observation well. The specific capacity of the recharge well during the October 1982 injection test was 18.3 gallons per minute per foot after 22.5 hours. The recharge well was redeveloped in June 1983. The specific capacity during the final pumping test of the pilot study was 27.5 gallons per minute per foot after 24.5 hours, compared to 35.8 gallons per minute per foot after 24 hours during"the May 1981 pre-injection pumping test. During the initial 5 years (1985-89) of operation of the Hueco bolson recharge project, water levels in the observation well were measured, and concentrations of selected water-quality constituents were determined. Water levels in six production wells located 0.25 to 0.6 mile from the injection wells of the recharge project declined at a rate of about 2 feet per year prior to 1985. Since 1980, water-level measurements indicate that the effects of pumping and recharge are approaching equilibrium.
No abstract available.
The aquifers in the lower Mesilla Valley of Texas and New Mexico provide water for irrigation, industrial use, and municipal supply. At present (1984), the shallow aquifer is used principally for irrigation. The medium-depth aquifer (the top of which is about 160 to 260 feet below land surface) and deep aquifer (about 460 to 680 feet below land surface) are used almost exclusively by the city of El Paso to provide about 28 percent of the city's ground-water withdrawal of about 82,000 acre-feet in 1980; however, a small percentage of the pumpage is from the shallow aquifer. The potential use of the medium-depth and deep aquifers for irrigation, together with a planned increase in pumping by the city, is causing concern on the part of El Paso water planners over the impact of this development on the limited supply from the two aquifers. A three-dimensional digital model of the aquifers was developed to evaluate the responses of water levels to various plans of development, with particular emphasis on the medium-depth and deep aquifers in and near the Canutillo well field. Simulations also were made to show the effect of eliminating seepage from the Rio Grande to the aquifer system. The model simulations indicate that if pumpage by the city of El Paso during 1^76-80 increases to 10,000 acre-feet, per year from the medium-depth aquifer and to 20,000 acre-feet per year from the deep aquifer, and elsewhere in the study area pumping was held constant at the 1975 rate, then additional lowering of water levels in representative observation wells would be as much as 24 feet in the medium-depth aquifer and as much as 52 feet in the deep aquifer. The water levels would decline sharply during the first few months, after which the levels would become nearly stable because the leakage between the aquifers probably is enough to balance the increased pumpage. The model also indicated that lining of the channel of the Rio Grande would result in an additional lowering of water levels in representative observation wells by 10 feet in the medium-depth aquifer and 8 feet in the deep aquifer. The accuracy of water levels simulated by a model is dependent on the accuracy and distribution of input data and how well model boundary conditions approximate actual boundary conditions. Because of a lack of hydro!ogic data (especial ly water-1 evel information) everywhere except the Canutillo wellfield area, because the simulated cone of depression reached two boundaries, and because the model contained an error and several deficiencies as explained in the "Discussion" section, the simulated results need to be interpreted carefully. The authors believe that the simulated results could be used best as a preliminary and conceptual evaluation of the pumping effects at the Canutillo well field, not as a quantitative interpretation. Although the patterns of simulated hydrographs of water-level change in observation wells in the Canutillo field generally may be correct, the amount of change simulated probably is not correct. Because the salinity of water in all three aquifers south of Canutillo is greater than elsewhere in the study area, there is potential for movement of this water northward toward the Canutillo well field if the cone of depression reaches that part of the aquifer system. This potential should be evaluated in future geohydrologic studies of the lower Mesilla Valley.
No abstract available.
Significant development of ground water in the El Paso area started in the early 1900's; pumping gradually increased to the early 1950's and has since accelerated commensurate with the area's rapid population growth. In 1980, withdrawals of ground water for municipal, industrial, and military supplies totaled 164,354 acre-feet (203 cubic hectometers) within the El Paso, Fort Bliss, and Ciudad Juarez, Mexico metropolitan area, and adjacent areas in Texas and New Mexico. Most of the water, 132,652 acre-feet (164 cubic hectometers), was pumped from the Hueco bolson, the principal aquifer. The Mesilla bolson and Rio Grande alluvium in the lower Mesilla Valley supplied 27,461 and 4,241 acre-feet (34 and 5 cubic hectometers) respectively. The cumulative 1906 through 1980 withdrawals of ground water from the Hueco bolson metro area total 3.0 million acre-feet (3.7 cubic kilometers)-about 2.2 million acre-feet (2.7 cubic kilometers) has been pumped in the United States and 0.8 million acre-feet (1.0 cubic kilometers) in the Republic of Mexico. These withdrawals have caused water levels to decline about 130 feet (40 meters) in the downtown sections of El Paso and Ciudad Juarez. In January 1980 the theoretically recoverable volume of freshwater in storage within the Texas part of the Hueco bolson metro area was estimated at 10.0 million acre-feet (12 cubic kilometers). Dissolved-solids concentrations in recent samples from Hueco bolson wells averaged 642 milligrams per liter in the Texas part of the metropolitan area and 736 milligrams per liter in Ciudad Juarez. Concentrations are increasing at an average-annual rate of about 10 milligrams per liter in Texas and 30 milligrams per liter in Juarez. Ground water in the lower Mesilla Valley is pumped for municipal and industrial supply and also for supplemental crop irrigation during years of inadequate surface-water supply in the Rio Grande. The 1979-80 withdrawals in the valley averaged about 31,000 acre-feet per year (38 cubic hectometers). Most of the water, about 21,000 to 22,000 acre-feet per year (26 to 27 cubic hectometers), was pumped from shallow, medium depth, and deep wells in the Canutillo field. Dissolved-solids concentrations from recent samples from Canutillo wells ranged from 252 to 1,854 milligrams per liter. Flow in the Rio Grande is diverted for crop irrigation in the United States and the Republic of Mexico, and for limited municipal supply in El Paso. The flow is regulated by releases from reservoirs in New Mexico and varies widely in both quantity and quality (dissolved-solids concentrations). During 1943-80, the flow at El Paso ranged from 57,481 acre-feet (71 cubic hectometers) in 1956 to 631,800 acre-feet (779 cubic hectometers) in 1943 and averaged about 317,000 acre-feet per year (391 cubic hectometers).
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The chemical and isotopic compositions of hot-spring water and gas are used to estimate subsurface temperatures. The basic assumptions inherent in the methods are seldom stipulated. These assumptions include (1) a temperature-dependent reaction at depth, (2) a supply of the solid phase involved in the reaction to permit saturation of the constituent used for geothermometry, (3) water-rock equilibrium at depth, (4) negligible re-equilibration as the water flows to the surface, and (5) no dilution or mixing of hot and cold water. The first three assumptions are probably good for a few reactions that occur in many places. The last two assumptions probably are not valid for many hot-spring systems; information obtained is therefore for the shallower parts of those systems, or a limiting temperature (generally a minimum) is indicated.