Conference Papers

Highly acidic contaminated water is moving through a shallow aquifer and interacting with streams near Globe, Arizona. Dissolved concentrations reach 3,000 mg/L iron, 150 mg/L copper, and 16,400 mg/L total dissloved solids; pH is as low as 3. 6. Samples from 16 PVC-cased observation wells include uncontaminated, contaminated, transition, and neutralized waters. Chemical reaction with sediments and

Five reports dealing with flood magnitude and frequency in urban areas in the Southeastern United States have been published during the past 2 years by the U. S. Geological Survey. These reports are based on data collected in Tampa and Tallahassee, Florida, Atlanta, Georgia, and several cities in Alabama and Tennessee. Each report contains regression equations useful for estimating flood peaks for

The U. S. Geological Survey has previously experienced the impacts on the National Mapping Program that are associated with implementing a readjustment of the horizontal datum. The impacts of these past readjustments were minimal compared to those of the current readjustment. The Geological Survey currently has produced and published over 60,000 different map products. The 7. 5-minute mapping prog

Fine sediment in channels, rivers, estuaries, and coastal waters undergo several physical processes including flocculation, floc disruption, deposition, bed consolidation, and resuspension. This paper presents a conceptual model and reviews mathematical models of these physical processes. Several general fine sediment models that simulate some of these processes are reviewed. These general models

Flow data were obtained in the surf zone across a barred profile during a storm. RMS cross-shore velocities due to waves in the intragravity band (wave periods greater than 20 s) had maxima in excess of 0. 5 m/s over the bar crest. For comparison to measured spectra, synthetic spectra of cross-shore flow were computed using measured nearshore profiles. The structure, in the infragravity band, of t

The U. S. Geological Survey (USGS) is the lead civilian mapping agency in the United States and is responsible for creating and maintaining numerous map series. In Alaska the standard topographic map series is at a scale of 1:63,360, and maps at that scale have been available from the USGS since the late 1940's. In 1981 USGS initiated production of orthophotoquads of Alaska, also at a scale of 1:6

The change in permeability with time of granite, quartzite, anorthosite and gabbro was measured while these rocks were subjected to a temperature gradient. Permeability reductions of up to two orders of magnitude were observed, with the greatest reactions occurring in the quartzite. These changes are thought to be caused by dissolution of minerals at high temperatures, and redeposition of the diss

Rhyolitic welded-tuff wallrocks of the epithermal base and precious metal veins of the Creede district were pervasively altered by the addition of more than two billion metric tons of potassium some 1. 5-2 million years before mineralization. Sodium, calcium and magnesium were strongly depleted, yielding a nearly binary quartz plus potassium feldspar assemblage containing as much as 13 weight perc

This report describes results of some preliminary analyses of Landsat-4 Thematic Mapper data for the NASA Landsat Image Quality Analysis program. The work is being done under interagency agreement S-12407-C between the U. S. Geological Survey and NASA-Goddard Space Flight Center. Landsat-4 TM scenes for Washington, D. C. Macon, Georgia (40050-15333, September 4, 1982) and Cape Canaveral, Florida h

Results of test drilling to depths of 2 km and data on the chemical and isotopic content of waters from hot springs and fumaroles permit a conceptual model of the present-day hydrothermal system in Long Valley caldera to be delineated. The model consists of two principal zones in which hot water flows laterally from west to east at depths less than 1 km within and around the resurgent dome. Maximu

A viable rheological model should consist of both a time-independent part and a time-dependent part. A generalized viscoplastic fluid model that has both parts as well as two major rheological properties (i. e. , the normal stress effect and soil yield criteria) is shown to be sufficiently accurate, yet practical, for general use in debris flow modeling. Other rheological models, such as the Bingh

The Ranger No. 1 and No. 3 orebodies contain about 124,000 tonnes U//3O//8 in highly chloritized metasediments of the lower Proterozoic Cahill Formation within about 500 m of the projected sub-Kombolgie Formation unconformity. In both orebodies, oxidized and reduced uranium minerals occur chiefly in quartzose schists that have highly variable amounts of muscovite, sericite, and chlorite. The effec