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Most workers agree that Proterozoic anorthosite massifs represent the crystallization products of mantle-derived magmas1,2, although the composition of the parental melts is a major unsolved petrological problem 3. As mantle-derived rocks, the massifs can be used as geochemical probes of their late Precambrian upper mantle sources. We report here Nd...

The partitioning of 25 trace elements between high-silica rhyolitic glass and unzoned phenocrysts of potassic and sodic sanidine, biotite, augite, ferrohedenbergite, hypersthene, fayalite, titanomagnetite, ilmenite, zircon, and allanite has been determined by INAA on suites of samples from the mildly peralkaline...

A detailed evaluation on the method of internal friction measurement by the stress-strain hysteresis loop method from 0.01 to 1 Hz at 10−8 to 10−7 strain amplitude and 23.9°C is presented. Significant systematic errors in relative phase measurement can result from convex end surfaces of the sample and stress sensor and from...

The large (mean height 25 m, spacing 300 m), relatively straight-crested dunes of the central Oregon coast migrate an average of 3.8 m/yr toward an azimuth of 26°. The dunes are transverse to the strong, south-southwesterly winter storm winds that are responsible for...

The geology of the part of Lydonia Canyon shoreward of the continental shelf edge on the southern side of Georges Bank was mapped using high-resolution seismic-reflection and side-scan sonar techniques and surface sediment grab samples. The head of the canyon incises Pleistocene deltaic deposits and Miocene shallow marine strata. Medium...

Syngenetic iron sulfides in sediments are formed from dissolved sulfide resulting from sulfate reduction and catabolism of organic matter by anaerobic bacteria. It has been shown that in recent marine sediments deposited below oxygenated waters there is a constant relationship between reduced sulfur and organic carbon which is generally independent...

Igneous rocks commonly have large magnetic susceptibilities so that high topographic relief in crystalline terrane can produce significant anomalies in aeromagnetic surveys. Topographic anomalies are particularly significant in relatively undeformed volcanic terrane because young volcanic rocks generally have large natural remanent magnetizations as well as large susceptibilities. These anomalies commonly...

Carbonatite lava and tephra are now well known. The only modern eruptive carbonatites, from Oldoinyo Lengai, Tanzania, are of alkali carbonatite, whereas all of the pre-modern examples are of calcite or dolomite. Chemical and stable isotope analyses were made of separate phases of Pliocene carbonatite tuffs of the Laetolil Beds...

The longitudinal component of the velocity of a particle at or near a glacier surface is considered, its position as a function of time being termed its trajectory. Functional relationships are derived for obtaining the trajectory from the spatial distribution of velocity and for obtaining the velocity...

The US National Water-Use Information Program is a cooperative program between the states and the Federal Government. The purpose of the program is to determine how much fresh and saline surface water and ground water is withdrawn and for what purpose, how much water is consumed during use, and how...

Seven granite plutons, spatially and genetically related to tin metalization, are exposed in a 170-km-long belt across northwestern Seward Peninsula, Alaska. These plutons are cupolas and epizonal composite stocks that consist of several textural varieties of biotite granite, including medium- to coarse-grained seriate...

Sands that did and did not liquefy at two sites during the 1979 Imperial Valley, Calif., earthquake (ML = 6.6) are identified and their properties evaluated. SPT tests were used to evaluate liquefaction susceptibility. Loose fine sands in an abandoned channel liquefied and produced sand boils, ground fissures, and a...

Temperature (T in °C) and mean vitrinite reflectance (Rm in %) of sedimentary organic matter samples from six liquid-dominated geothermal systems plot about a line approximated by a regression equation of the form Rm = 0.435 exp 0.00683T. The reflectance data from these systems are strongly temperature-dependent,...

Nonmarine ostracode species are indicative of the physical and chemical nature of lacustrine environments. Although salinity has traditionally been regarded as one of the more important parameters that affect the occurrence patterns of lacustrine ostracodes, examination of the solute composition and salinities of...

Tectonism in SW Wyoming and adjoining areas, and fluctuations of sea level in the central USA during the mid-Cretaceous are represented by the regional stratigraphy of the Frontier Formation. The Frontier consists mainly of clastic rocks that were deposited in marine and nonmarine environments during latest Albian, Cenomanian, Turonian, and...

Hydrologic testing in an offshore oil well abandoned by Tenneco, Inc., determined the position of the saltwater-freshwater interface in Tertiary limestones underlying the Florida-Georgia continental shelf of the U.S.A. Previous drilling (JOIDES and U.S.G.S. AMCOR projects) established the existence of freshwater far offshore in this area. At the Tenneco well...

The analysis of the New Brunswick earthquake of January 9, 1982, has important implications for the evaluation of seismic hazards in eastern North America. Although moderate in size (mb 5.7), it was well-recorded teleseismically. Source characteristics of this earthquake have been determined from analysis of data that were digitally recorded by...

As Cain (1979) indicated might happen in the last IUGG quadrennial report, added resources were made available during the past few years and a real impulse was added to the geomagnetic work in the US by the launching of the MAGSAT Satellite. This new effort paid off in terms of...

Examination of SEASAT SAR images of eastern Maryland and Virginia reveals botanical distinctions between vegetated lowland areas and adjacent upland areas. Radar returns from the lowland areas can be either brighter or darker than returns from the upland forests. Scattering models and scatterometer measurements predict an increase of 6 dB...

A submerged delta of the Merrimack River, located offshore between Cape Ann, Massachusetts, and the New Hampshire border, indicates a postglacial low relative see-level stand of about -47 m. The low stand is inferred to date to 10,500 yr B.P., but a lack of age control makes this assignment uncertain....

The choice of agents for chemical immobilization of mule deer (Odocoileus hemionus) is a problem with a simple and effective solution, in my opinion. I recommend combinations of etorphine hydrochloride (M199©) and xylazine hydrochloride (Rompun©) administered intravenously and reversed intravenously. I have used this combination on hundreds of mule deer...

Areas of the U.S. Gulf Coast, both onshore and offshore, are among the petroliferous regions of the United States. In offshore Louisiana and Texas, most oil and gas is associated with structurally controlled traps on the crest or flanks of domes created by the diapiric movement of salt. These structures...

Venezuela has been affected by destructive earthquakes for the past four centuries. According to entries in the national seismic catalog, there have been about 180 earthquakes which have caused some type of damage to the country. The most catastrophic earthquake occurred on March 26, 1812, on the Bocono fault system...

On June 4, 1982, two full dredge hauls of fresh lava were recovered from the upper flanks of Kavachi submarine volcano, Solomon Islands, in the western Pacific Ocean, from the water depths of 1,200 and 2,700 feet. the shallower dredge site was within 0.5 mile of the active submarine vent...

The calculation of high-temperature geothermal resources ( greater than 150 degree C) in the United States has been done by estimating the temperature, area, and thickness of each identified system. These data, along with a general model for recoverability of geothermal energy and a calculation that takes account of the...