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Temperature histories obtained from transient heat-conduction theory are applicable to most dikes despite potential complicating effects related to magma flow during emplacement, groundwater circulation, and metamorphic reaction during cooling. Here. machine-independent FORTRAN 77 programs are presented to calculate temperatures in and around dikes as they cool conductively. Analytical solutions can...

The depth to the brittle-ductile transition in the crust is often defined by the intersection of a shear resistance relation in the brittle upper crust that increases linearly with depth and a power law relation for ductile flow in the lower crust that depends strongly on...

Cleat and clastic dikes of Middle Pennsylvanian-age coal beds of the Illinois and Forest City basins of Illinois, Iowa, Missouri, and Kansas locally contain appreciable amounts of sphalerite within a kaolinite-pyrite-sphalerite (+ or - pyrite)-calcite paragenetic sequence. The sphalerite and associated minerals are of interest as a partial record of...

Elevated concentrations of selenium in water, bottom sediment, and biota were noted during a reconnaissance investigation of the Kendrick Reclamation Project in central Wyoming. Dissolved-selenium concentrations in 11 of 24 samples of surface or ground water exceeded the national drinking-water standard of 10 micrograms per liter. Bottom-sediment samples contained concentrations...

Existing onsite measurements of local scour at bridge piers were assembled and analyzed to obtain an equation that predicts the expected maximum depth of local scour at a bridge pier. A safety factor is suggested that provides a reasonable margin of error for design purposes....

Groundwater development has resulted in lowered water levels and seawater intrusion in the Pajaro Valley, California. An investigation was undertaken to describe the geohydrology of the groundwater flow system and to evaluate the response of the system to pumping stresses by using a mathematical model. The aquifer system consists of...

[No abstract available]...

A method is derived for determining the dependence of radar backscatter on incidence angle that is applicable to the region corresponding to a particular radar image. The method is based on enforcing mathematical consistency between the frequency distribution of the image's pixel signals (histogram of DN values with suitable normalizations)...

Sulfur was analyzed in more than 200 lava samples from five drill holes located on the east rift zone of Kilauea volcano on the island of Hawaii. The sulfur content is a gage of whether lava was erupted subaerially (low sulfur) or erupted subaqueously (high sulfur). Despite considerable variation, sulfur...

The two-dimensional seismic response of the Salt Lake valley to near- and far-field earthquakes has been investigated from simulations of vertically incident plane waves and from normal-faulting earthquakes generated on the basin-bounding Wasatch fault. The response to normal faulting earthquakes was simulated using a two-dimensional finite-element method and the plane-wave...

Hualalai Volcano, Hawaii, is best known for the abundant and varied xenoliths included in the historic 1800 Kaupulehu alkalic basalt flow. Xenoliths, which range in composition from dunite to anorthosite, are concentrated at 915-m elevation in the flow. Rare cumulate ultramafic xenoliths, which include websterite, olivine...

Natural gas production in the Anadarko basin comes from three geographically separated areas that can be differentiated by age of reservoir and by inferred nature of organic, thermal origin of the gases. In the central basin, non-associated gases are produced mainly from Upper Mississippian and Pennsylvanian sandstones. Gas samples are...

Trends in rainfall-adjusted sulfate concentration were assessed for 5-yr subrecords of the 14.5–17 yr of monthly bulk-deposition data from five stations in New York by using the seasonal Kendall test. For the 5-yr subrecord from 1978 to 1982, the trends for the bulk deposition were similar to those for weekly...

We attribute most of the development of extensive fractures in the Tharsis region to discrete tectonic provinces within the region, rather than to Tharsis as a single entity. One of these provinces is in Syria Planum. Faults and collapse structures in the Syria Planum tectonic province on Mars are grouped...

[No abstract available]...

Eleven radiocarbon age determinations clearly show that a lens of Holocene fluvial organic debris on the Alaskan Arctic Coastal Plain contains mostly pre-Holocene organic material. Radio-carbon ages of identified plant macrofossils indicate the material was deposited about 9000 to 9500 yr B.P. Radiocarbon analyses of bulk samples from this deposit,...

No abstract available....

Chamaebatiaria and Chamaebatia, two characteristic genera of the Californian floristic province, are traditionally placed in different subfamilies of Rosaceae, Spiraeoideae and Rosoideae, respectively. Analysis of the foliar and reproductive characters of the extant species of these genera indicates that the two genera could be closely related and the assignment of Chamaebatia to Rosoideae invalid. Fossil...

Over 5% of heat in the western United States is lost through Quaternary silicic volcanic centers, including the Valles caldera in north central New Mexico. These centers are the sites of major hydrothermal activity and upper crustal metamorphism, metasomatism, and mineralization, producing associated geothermal resources. We present new heat flow...

One approach that has been used in performing a nonparametric test for monotonic trend in a hydrologic time series consists of a two-stage analysis. First, a regression equation is estimated for the variable being tested as a function of an exogenous variable. A nonparametric trend test such as...

Sandstones and dolomites of the Permian upper part of the Minnelusa Formation are treated here as four-component systems consisting of fluid-filled pore space, quartz, dolomite, and anhydrite. Response equations of sonic, neutron, and density logs form a system of four simultaneous equations. With four equations and four unknowns, the composition...

K-Ar ages and paleomagnetic data for basalt samples from a new core hole (site E) at the Idaho National Engineering Laboratory (INEL) indicate that the age of the reversed polarity event recorded in Snake River Plain lavas is older than 465±50 ka (1000 years before present) reported previously by Champion...

The objective of this paper is to discuss leading-edge directions in paleoseismology and seismic geology, particularly as they relate to characterizing seismic sources. The paper builds on earlier articles that discuss some of these trends (Schwartz and Coppersmith, 1986; Schwartz, 1987). There are several areas that appear to be especially...

[No abstract available]...