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No abstract available at this time...

SPalladium, platinum, and rhodium concentrations are reported for rocks belonging to the Peridotite zone of the Ultramafic series and the Basal series of the late Archcan Stillwater Complex, a suite of Stillwater-associated sills and dikes, and the metamorphic rocks lying within the contact aureole of the complex. Mean values do...

Pb, Sr, Nd, and Hf isotopic relationships among basalts from the Hawaiian Islands suggest that these basalts were derived from three sources; the oceanic lithosphere (Kea end member), the depleted asthenosphere (posterosional end member) and a deep-mantle plume (Koolau end member).Hawaiian tholeiites are derived within the lithosphere and the isotopic...

For a rare and brief instant in geologic time, we can imagine that the sulfurous, chromatic surface of Io (one of the satellites of Jupiter) lies quiet. Perhaps stars glisten brilliantly through the tenuous nigh sky. Here and there, thick icy fogs enshroud fumaroles where sulfur dioxide leaks from the...

No abstract available at this time...

Certain geologic media are known to have small permeability; subsurface environments composed of these media and lacking well developed secondary permeability have groundwater flow sytems with many distinctive characteristics. Moreover, groundwater flow in these environments appears to influence the evolution of certain hydrologic, geologic, and geochemical systems, may affect the...

The whooping crane has been the subject of intensive scientific study and management because it is an endangered species and has high public interest. Programs have been developed to identify critical habitat, to increase production through captive breeding, and in recent years, to use sandhill cranes (Grus canadensis) as surrogate...

Situated in a submerged continental rift, Pantelleria is a volcanic island with a subaerial eruptive history longer than 300 Ka. Its eruptive behavior, edifice morphologies, and complex, multiunit geologic history are representative of strongly peralkaline centers. It is dominated by the 6-km-wide Cinque Denti caldera, which formed ca. 45 Ka...

An assemblage of pyroxenite, peridotite, and mafic granulite xenoliths contained in the toe of a 10 Ma trachybasalt flow remnant overlying Late Cretaceous granitoids indicates the presence of a mafic-ultramafic complex beneath the Sierra Nevada batholith. Olivine-free pyroxenites that include orthopyroxenites, websterites, and clinopyroxenites are dominant. Primary igneous textures...

Laboratory spectral reflectance measurements were made in the 0.4- to 2.5-mu m wavelength range for samples collected from four North American carbonatite-alkalic igneous rock complexes. Alkalic rock spectra produced few absorption features; however, the carbonatites typically showed conspicuous carbonate, ferric and ferrous iron, and in some cases rare earth element...

Drilling on Leg 80 of the Deep Sea Drilling Project-International Phase of Ocean Drilling was conducted on a transect of four sites (548-551) across the continent-ocean boundary at Goban Spur, a prominent southwest-trending structural and topographic high on the Irish continental slope. Drilling results have been integrated with physiographic, gravimetric,...

Wildlife in an oak forest on Blue Mountain was studied 10 km upwind (Bake Oven Knob site) and 2 km downwind (Palmerton site) of two zinc smelters in eastern Pennsylvania, USA. Previous studies at sites near these smelters had shown changes in populations of soil microflora, lichens, green plants and...

The austral peregrine falcon (Falco peregrinus cassini) was studied in the Andean foot- hills and across the Patagonian steppe from November to December 1981. The birds under study (18 pairs) were reproducing at or near normal (pre-DDT) levels for other races. Pesticide residues, while elevated, were well below the values...

Autumnal attraction to man-made lighting causes heavy mortality in fledgling Hawaiian seabirds: Newell's Shearwater (Puffinus auricularis newelli), Dark-rumped Petrel (Pterodroma phaeopygia sandwichensis), and Band-rumped Storm-Petrel (Oceanodroma castro). These threatened, endangered, and rare species (respectively) approach and circle lights on their first flight from mountain nesting colonies on the island of...

A large earthquake leaves clues of its nature that can be interpreted only by a diverse group of scientists. We cannot hope to form a coherent picture of the Borah Peak shock, a rare Great Basin event, without listening to each other and reflecting on the historical and geological record...

The Jabal Habashi quadrangle contains formations of Lower Paleozoic and Cenozoic age, unconformably overlying part of the Precambrian Arabian Shield. The Precambrian formations include metamorphosed and strongly deformed volcanic and volcaniclastic rocks and plutons of calc-alkalic, mafic to intermediate composition, dated at about 645 Ma. These are unconformably overlain by...

The Austin Farm bed was once mined form an adit in the SE1/4 sec, T. 136 N., R. 101 W. Its westerly outcrop extends from that point northward along the east side and north end of the valley of Third Creek at elevations between about 2740 and 2800 ft. It...

Parts of the Fossil Ridge Wilderness Study Area have a high resource potential for gold and silver in small deposits, uranium in medium-size deposits, and high-calcium limestone in large deposits. Parts have a moderate to high potential for uranium, thorium, and light rare-earth elements in small- to medium-size deposits, a...

No abstract available....

Reconnaissance geochemical exploration for rare metals in plutons of syenite and shonkinite disclosed generally less than 20 ppm Nb in rocks, wadi sediments, and concentrates. The sparsity of Nb is accompanied by low values for La, Sn, W, Y, and Zr and relatively high but insignificant values for Be and...

The mineralogy of three drill cores from the apogranite at Jabal Sa'id was determined principally to identify those minerals containing rare earths, niobium, tantalum, thorium, zirconium, and tin. Heavy mineral studies of two other drill cores indicate that the deposit is enriched in rare earths. The principal rare earth minerals...

Fourteen plutons of Late Proterozoie age potentially favorable for rare-element mineralization have been identified in a geochemical and petrographic assessment of felsic plutonic rocks in the north-central Arabian Shield (lat 23°00'-25°00' N., long 40°00'-45°00' E.). The plutons are highly fractionated, leucocratic granitoids assigned to a major magmatic pulse that spanned...

The Al Hufayr quadrangle (27/41 A) lies at the northern edge of the Arabian Shield between lat 27 30' and 28 00' N. and long 41 00' and 41 30' E. A cataclastically foliated syenogranite, the oldest rock exposed in the quadrangle, crops out in a restricted area in the...

Geochemical reconnaissance for rare metals in plutons of albite-muscovite granite and quartz monzonite in the vicinity of Jabal Lababa disclosed positive geochemical anomalies for beryllium, tantalum, thorium, lanthanum, niobium, tin, yttrium, and zirconium. The low anomalous values for the rare metals in rocks and the short mechanical dispersion trains, seldom...