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Pele's hair is a filamentous variety of brown sideromelane glass that forms during eruption of basaltic lava. Strands of Pele's hair form from droplets of lava that are spun or stretched into filaments during quenching, and others may form as chilled streamers of lava. Common elongate vesicles, sometimes twisted, indicate...

Volatile-filled vesicles are present in minor amounts in all samples of mid-ocean basalt yet collected (and presumably erupted) down to depths of 4.8 km. When such vesicles are pierced in liquid under standard conditions, the volume expansion of the gas is 0.2 ?? 0.05 times the eruption pressure in bars...

The Paloma Valley ring complex is one of the numerous plutons that make up the Cretaceous southern California batholith. The complex is composite, consisting of (1) an older, single ring dike and two subsidiary short-arced inner dikes, and (2) a younger set of thin short-arced dikes largely inside the older...

The U.S. Geological Survey has responsibility for investigating the Nation's water resources for source, availability, quantity, and quality. This paper describes the Geological Survey's research on organic substances in water and fluvial sediments. Results and ongoing studies are examined. Typical research includes: Separation, concentration, and chromatographic identification of volatile acids;...

Disseminated, Carlin-type, gold deposits are associated with a volatile suite of elements consisting of Hg, As, Sb, W, and sometimes, but not always, Au. Geochemical exploration for this type of disseminated deposit depends upon recognizing the significance of this volatile suite and interpreting it in light of other geologic and...

Two surface samples collected from the Chryse Planitia region of Mars were heated to temperatures up to 500??C, and the volatiles that they evolved were analyzed with a gas chromatograph-mass spectrometer. Only water and carbon dioxide were detected. This implies that organic compounds have not accumulated to the extent that...

An atomic absorption method is described for the determination of traces of tin in rocks, soils, and stream sediments. A dried mixture of the sample and ammonium iodide is heated to volatilize tin tetraiodide -which is then dissolved in 5 % hydrochloric acid, extracted into TOPO-MIBK, and aspirated into a...

Metallic Fe content and S abundance are inversely correlated in mare basalts. Either S volatilization from the melt results in reduction of Fe2+ to Fe0 or else high S content decreases Fe0 activity in the melt, thus explaining the correlation. All considerations favor the model that metallic iron in mare basalts is due...

After acid decomposition and evaporation to volatilize silica, samples containing 0.5 6 μg Nb are fused with pyrosulfate and dissolved in hydrochloric acid tartaric acid. Niobium is separated by thiocyanate extraction with amyl alcohol and back-extracting from the organic solvent with dilute hydrofluoric acid. Niobium is reacted with 4-(2-pyridylazo)-resorcinol to...

Exudates from conifer trees, presumably consisting largely of volatile materials, were sampled at 19 subalpine localitites in Colorado and Idaho where anomalous amounts of several metals were determined in vegetation and mull during previous geochemical testing. The trees sampled were lodgepole pine...

Total mercury in a variety of substances is determined rapidly and precisely by direct sample combustion, collection of released mercury by amalgamation, and photometric measurement of mercury volatilized from the heated amalgam. Up to 0.2 g fish tissue is heated in a stream of O2 (1.2 L/min) for 3.5 min in...

Dredge hauls of fresh submarine basalt collected from the axis of the Reykjanes Ridge (Mid-Atlantic Ridge) south of Iceland were taken aboard R/ V TRIDENT in 1967 and 1971. The samples show systematic changes as the water depth of collection (and eruption) decreases: radially elongate vesicles and concentric zones of vesicles appear...

The amount of water and sulfur in pumice erupted during periods of vigorous activity during the 1969-71 Mauna Ulu eruption varied inversely with fountain height because of degassing during the fountaining. The pumice lost about 0.05 wt percent water and 0.003 wt percent sulfur during fountaining to heights of 400-540 m. Analyses suggest that the...

The phase relations of three basalts, the Picture Gorge tholeiite, the 1921 Kilauea olivine tholeiite, and the 1801 Hualalai alkali basalt, were studied at 5 kb water pressure, 680–1000°C, at the oxygen fugacities of the quartz-fayalite-magnetite (QFM) and hematite-magnetite (HM) buffers.In the range 680–850 °C, the crystalline assemblage...

Fayette County is in central West Virginia. Rocks exposed at the surface are about 3,200 feet thick and comprise the Pocahontas, New River, Kanawha, and Allegheny Formations of Pennsylvanian age. The stratigraphic relations and distribution of coal in these formations were studied by the U.S. Geological Survey in connection with a low-sulfur coal program...

The first 4 months of Mariner 9 photography of the south polar region are discussed. Three major geological units have been recognized, separated by erosional unconformities. From oldest to youngest they are: cratered terrain, pitted plains, and laminated terrain. The latter unit is unique in occurrence to the polar region,...

An experiment centering around a mass spectrometer is described, which is aimed at the identification of organic substances present in the top 10 cm of the surface of Mars and an analysis of the atmosphere for major and minor constituents as well as isotopic abundances. In addition, an indication of...

The geochemist can contribute much information of value toward assessing the effect of environment, including inorganic pollution, on health....

A review of the literature indicates that a reasonable estimate of the composition of the earth's core is iron with Ni0–5, Si10–25 (wt.%). Thermodynamic calculations and comparison of chondritic with terrestrial abundances indicate that 1 wt.% each of Mn, P, and Cr might also be present. A core of this composition...

Deep sea pillow basalts dredged from the ocean floor show that vesicularity changes with composition as well as with depth. Alkalic basalts are more vesicular than tholeiitic basalts erupted at the same depth. The vesicularity data, when related to experimentally determined solubility of water in basalt, indicate that K-poor oceanic...

Ocean-floor dredging and submarine photography in the Revillagigedo region off the west coast of Mexico reveal that the dominant exposed rock of the submarine part of the large island-forming volcanoes (Roca Partida and San Benedicto) is a uniform alkali pillow basalt; more siliceous rocks are exposed on the upper, subaerial...

The Ar36 content of densely welded glasses from ash-flow units provides a means by which the amount of air entrapped and subsequently resorbed by the glasses during compaction and welding may be calculated. The amount of air measured in glasses from nine upper Tertiary ash-flow sheets...

Under favorable conditions the chemistry of hot springs may give reliable indications of subsurface temperatures and circulation patterns. These chemical indicators can be classified by the type of process involved:IndicatorDominant ProcessThe silica...

The genesis of granitic igneous pegmatites is here considered in terms of a model conceived from results of field and laboratory studies and subsequently tested by means of experimental investigations. This model emphasizes the roles of water (and/or other relatively volatile substances), both as a dissolved constituent in granitic magmas...