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Terrain softening, fretted channels, debris flows, and closed depressions indicate that at least the upper 2 km of the cratered uplands at high latitudes (>30??) contain ice in amounts that exceed the porosity, estimated to be 10-20 percent. Theoretical studies, and lack of these features in the cratered uplands at...

The author presents initial results of an ongoing study of Southeast Florida coastal lagoon lakes. Objectives include presenting environmental conditions within and adjacent to the lagoons under a variety of hydrologic conditions and to determine water-quality changes in ground water and surface water and how these changes in water quality...

On Yakobi Island and at Mirror Harbor on the northwest coast of Chichagof Island, gabbronorite occurs as irregular bodies, as much as 5.5 km in maximum dimension, mostly within a 40 to 43 m.y. composite pluton consisting largely of tonalite. The gab-bronorites are the host rocks for a magmatic nickel-copper...

This is a description, illustrated with photographs, of the 1986 eruptions of Augustine, Pavlof and Akutan volcanoes. Augustine erupted pyroclastic flows, a large eruptive column, ash, and eventually a dome. Pavlof had an important Strombolian eruption which was one of the biggest in the last 30 years. Akutan had a...

Major slope failures are a significant degradational process at volcanoes. Slope failures and associated explosive eruptions have resulted in more than 20 000 fatalities in the past 400 years; the historic record provides evidence for at least six of these events in the past century. Several historic debris avalanches exceed...

Changing interactions of lithospheric plates provide the framework for this review of the 3100 m.y. geological history of some 3 million km2 of mountains, deserts, plateaux and plains. The Precambrian to Neogene development of the western U.S.A. is outlined in terms of plate collisions, subduction events and deformation of lithospheric...

In 1981 and 1982, detailed bathymetric and side-scan sonar surveys were made of an area of the sea floor north of Prudhoe Bay, Alaska, to study the changing characteristics of the seabed at the inner boundary of the stamukhi zone, the...

The amplitude and phase of 11 tidal constituents for the English Channel and southern North Sea are calculated using a frequency domain, finite element model. The governing equations - the shallow water equations - are modifed such that sea level is calculated using an elliptic equation of the Helmholz type...

The High Plains aquifer, which underlies about 174,000 square miles (1 square mile = 2.59 km2) in the Great Plains, is the principal source of water in one of the nation's major agricultural areas. This paper examines relationships between the scale of management areas and physical factors, resulting from the...

The photodegradation and degradation products of hexachlorocyclopentadiene (C-56) in aqueous solutions were studied in the laboratory. In each case, the half-life of C-56 was less than 4 min when exposed to sunlight. At least eight degradation products were positively or tentatively identified: 2,3,4,4,5-Pentachloro-2-cyclopentenone, hexachloro-2-cyclopentenone and hexachloro-3-cyclopentenone were the primary photodegradation...

Several methods have been developed and used to extract and chemically analyze the two major types of fluid inclusions in bedded salt from the Palo Duro Basin, Texas. Data on the ratio K: Ca: Mg were obtained on a few of the clouds of tiny inclusions in "chevron" salt, representing...

The US Geological Survey is utilizing a national network of more than 1000 satellite data-collection stations, four satellite-relay direct-readout ground stations, and more than 50 computers linked together in a private telecommunications network to acquire, process, and distribute hydrological data in near real-time. The four Survey offices operating a satellite...

Basalt pillow lava with glassy rims was dredged from 17 sites along the Gorda Ridge between latitudes 43°N and 40.8°N. All samples are low-K2O mid-ocean ridge tholeiitic basalt having a narrow compositional range with Mg numbers clustered around 60–62; more primitive and evolved compositions are present but rare. None of...

The Lassen hydrothermal system, like a number of other systems in regions of moderate to great topographic relief, includes steam-heated features at higher elevations and high-chloride springs at lower elevations, connected to and fed by a single circulation system at depth. Two conceptual models for such systems are presented. They...

Methodologies that account for specific types of chemical reactions in the simulation of solute transport can be developed so they are compatible with solution algorithms employed in existing transport codes. This enables the simulation of reactive transport in complex multidimensional flow regimes, and provides a means for existing codes to...

No abstract available....

The pattern of lattice preferred orientation (texture) in deformed rocks is an expression of the strain path and the acting deformation mechanisms. A first indication about the strain path is given by the symmetry of pole figures: coaxial deformation produces orthorhombic pole figures, while non-coaxial deformation yields monoclinic or triclinic...

Samples of total suspended matter (TSM) were collected at the surface over the northern outer continental margin of the Bering Sea during the summers of 1980 and 1981. Volume concentrations of surface TSM averaged 0.6 and 1.1 mg l−1 for 1980 and...

Conventional heat flow data are sparse for northern Michigan. The groundwater silica heat flow estimator expands the database sufficiently to allow regional variations in heat flow to be examined. Heat flow shows a pattern of alternating highs and lows trending ESE across the Upper Peninsula and Lake Superior. The informal...

A number of mixed valence iron oxides and silicates (e.g., magnetite, ilvaite) exhibit thermally induced electron delocalization between adjacent Fe2+ and Fe3+ ions and optically induced electronic transitions which are assigned to Fe2+→Fe3+ intervalence charge transfer. In this paper, the mechanism of electron delocalization (i.e., polarons versus itinerant electrons) and the nature...

This paper presents closed-form solutions for the stress field induced by gravity in anisotropic rock masses. These rocks are assumed to be laterally restrained and are modelled as a homogeneous, orthotropic or transversely isotropic, linearly elastic material. The analysis, constrained by the thermodynamic requirement that strain energy be positive definite,...

Recent studies document the effectiveness of sea ice in reshaping the seafloor of the inner shelf into sharp-relief features, including ice gouges with jagged flanking ridges, ice-wallow relief, and 2- to 6-m-deep strudel-scour craters. These ice-related relief forms are in disequilibrium with classic open-water hydraulic processes and thus are smoothed...

K-Ar ages of illite alteration associated with Middle Proterozoic Athabasca unconformity-type U deposits in Saskatchewan range from 414 to 1493 Ma. The K-Ar ages correlate with water contents and δD values such that illites with young K-Ar ages have δD values as low as −169 and water contents as high...

An application is described of the branch-network flow model, BRANCH, to the upper Alabama River system in central Alabama. The model is used to simulate one-dimensional unsteady flows and water surface elevations in approximately 60 river miles of the Alabama River system. Preliminary calibration was made using 72 hours of...

The U.S. Geological Survey has conducted geochemical studies in the Indian Pass (CDCA-355), 124 km2, and Picacho Peak (CDCA-355A), 23 km2, Wilderness Study Areas (WSA's) as part of a program to evaluate the mineral resource potential of designated areas in the California Desert Conservation Area. These two WSA's are of...