Conference Papers

Two U. S. Geological Survey computer programs are modified and linked to predict the cumulative impact of iron and manganese oxidation in coal-mine discharge on the dissolved-chemical quality of a receiving stream. The coupled programs calculate the changes in dissolved-iron, dissolved-manganese, and dissolved-oxygen concentrations, and the pH of surface water downstream from the discharge. The cu

A small-diameter three-component fluxgate magnetometer probe with gyroscopic and inclinometer orientation has been developed to meet U. S. Geological Survey design and performance specifications for measurement of the direction and intensity of the Earth's magnetic field in vertical and inclined boreholes. The orthogonal fluxgate magnetometer elements have a measurement resolution of 10 nanoteslas

A three-dimensional high-resolution seismic study of the summit caldera of Newberry Volcano, Oregon, was conducted by the U. S. Geological Survey using an adaptation of the method applied by Nercessian et al. , (1984). Preliminary interpretation of the traveltime residuals reveals a ring of high P-velocity material coinciding with the inner ring fault system of the caldera in the upper 2 km. A zon

Plane-strain solutions are used to analyze the influence of topography on the state of stress at Yucca Mountain, Nye County, Nevada. The results are in good agreement with the measured stress components obtained in drill holes by the hydraulic-fracturing technique, particularly those measured directly beneath the crest of the ridge, and indicate that these stresses are gravitationally induced. A s

Transient electromagnetic soundings were used to map the geoelectrical structure of Newberry Volcano in central Oregon. An extensive conductor was found to underlie the volcano and to have resistivities from 20 OMEGA m to 72 OMEGA m. The depth to the conductor ranges from 410 m to 870 m. Inside the caldera, low basement resistivities are the result of hot fluids. The cause of the conductor outside

Several borehole geophysical techniques have been developed in recent years. Assaying technique development has been concentrated on nuclear methods, with some progress being made on using electrical and magnetic properties for mineral identification. Adaptation of conventional surface geophysical techniques to the borehole for locating near-misses of mineralized zones has led to the development o

In August of 1982, a single-user, dual-translator, automated powder diffraction system was purchased by the Denver Research Institute for use on project work in the Chemical and Materials Sciences Division. Within a short period of time, the system had already become saturated with users. Scheduling conflicts arose. In view of these problems, an answer was sought in the form of hardware and softwa

The paper discusses a carefully designed model program and its complementary complete description of all of the physical and mathematical concepts used in the model. The model program consists of a series of independent subroutines called modules. Modules are grouped by hydrologic function into 'packages. ' A report describing the model was written in three levels. At one level the hydrologic conc

Urban stormwater hydrology studies in the U. S. Geological Survey are currently focused on compilation of national data bases containing flood-peak and short time-interval rainfall, discharge and water-quality information for urban watersheds. Current data bases, updated annually, are nationwide in scope. Supplementing the national data files are published reports of interpretative analyses, a map

Volatilization is a physical process of importance in determining the fate of many organic compounds in streams and rivers. This process is frequently described by the conceptual-two-film model. The model assumes uniformly mixed water and air phases separated by thin films of water and air in which mass transfer is by molecular diffusion. Mass-transfer coefficients for the water and air films are

Because these springs contain substantial amounts of dissolved chloride, halite and sylvite are found above the water level as evaporitic deposits, along with gypsum. One spring is depositing pyrite that contains significant amounts of arsenic, antimony, and thallium. A yellow compound, composed of arsenic and sulfur, is being deposited in another spring. Arsenic and antimony concentrations are hi

As a part of the Geological Survey's program of releasing water data to the public, two large-scale computerized systems are maintained. The National Water Data Storage and Retrieval System was developed to provide more effective and efficient management of data-releasing activities and provides for the processing, storage, and retrieval of surface-water, ground-water and water-quality data. Anoth