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Kodiak Seamount and Giacomini Guyot have been dated at 22.6 ± 1.1 and 19.9 ± 1.0 [2σ (standard deviation)] × 106 years, respectively. Concordant whole-rock and plagioclase potassium-argon dates and fission-track apatite ages demonstrate that significant quantities of excess radiogenic 40Ar are not present in the dated samples. These...

As spreading at known interarc basins occurs to the west of westward-dipping subduction zones, and movement of the lower plates is also to the west, it is suggested that all plates move chiefly westward. Rates of motion are equal to a net difference between eastward and westward transport on semidiurnal...

Greenstone of basaltic composition forms the middle part of the Windermere System in southern British Columbia and the correlative Windermere Group in northeastern Washington. The greenstone, together with the rest of the Windermere in this region, is highly sheared, altered, and metamorphosed, except for a small exposed mass of relatively...

No abstract available....

Initial Sr87/Sr86 of granitic rocks which are exposed north of the Garlock fault in California, and which represent the entire 130-m.y. time span of emplacement during the Mesozoic, ranges mainly from 0.7031 to 0.7082, with one value of 0.7094. A systematic areal variation, independent of age, exists for initial Sr87/Sr86 in these...

A theoretical analysis of acoustic waves refracted by a spherical boundary across which velocity and density increase abruptly and below which velocity and density may either increase or decrease continuously with depth is formulated in terms of waves generated at a harmonic point source and scattered by a radially...

No abstract available....

Six alkali feldspar and two whole-rock samples of granitic rocks from the Sierra Nevada batholith and adjacent Klamath Mountains were analyzed for their lead-isotope compositions. The samples represented each of three 87Sr/86Sr groupings (< 0.704, 0.704 to 0.706, and > 0.706) for granitic rocks north of the Garlock fault in California....

The 18.6-yr cycle of the Moon's nodes dominates the annual means of high water, low water, and range at Boston and at other East Coast harbors. The maxima and minima of the high-water and range curves agree closely with the 180° and 0° long. yr, respectively, of the Moon's ascending...

A procedure has been devised for the fractionation of humic acid samples from different environments. This procedure involves fractionation of the sample by adsorption chromatography on a Sephadex G-50 column followed by chromatography on either a G-25 or a G-100 column. The fractions of the solutions are then examined by small angle X-ray scattering. Three...

Volcanic rocks in the vicinity of the massive sulfide deposits at the United Verde mine, Jerome, Ariz., have been modified in several periods of hydrothermal alteration and greenschist metamorphism. Chlorite, 2M, mica (sericite), and epidote are characteristic alteration products. Microprobe analyses for sericite, chlorite, and epidote are recalculated to structural formulas by the method employing oxygen...

Ponding studies at the Woodbury recharge basin on Long Island, N.Y., show that the principal zones controlling infiltration are a surface-loam stratum and an intermediate gravelly, sandy loam stratum. The saturated hydraulic conductivities of these strata are 0.90 and 0.1 ft per day, respectively. The surface loam acts as the principal zone controlling infiltration until...

Problems of underground storage of waste involve geology in its broadest sense, including hydrology, geochemistry, and geophysics. Wastes may be solid, liquid, or gaseous, and they may be chemically toxic or noxious, esthetically offensive, or radioactive. Some wastes require only temporary containment, whereas others must be isolated for indefinitely long periods. The means and locale...

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...

Uranium, thorium, and potassium contents were determined in 94 samples of drill cuttings from a 9,774-foot-deep exploratory hole drilled entirely in crystalline schists of the basement complex of the Yukon-Tanana Upland. The data indicate two distinctively different rock types and reflect differences in the calcite content of the rock. Zones of anomalously high concentrations of...

The sequence of mid-Cenozoic volcanic events in the western San Juan Mountains is closely analogous to that elsewhere in the San Juan volcanic field. The Lake Fork, Picayune, and San Juan Formations were erupted from a cluster of central volcanoes from 35 to 30 m.y. ago, when dominant activity shifted to more silicic ash-flow eruptions...

An atomic absorption spectrophotometric method has been developed for the determination of seven metal ions in the hydroxylamine extract of soils and sediments. Mn, Fe, and Zn are directly determined in the aqueous extract upon dilution. Co, Ni, Cu, and Pb in a separate aliquot of the extract are chelated with APDC (ammonium pyrrolidine dithiocarbamate)...

Fossil pollen was recovered at Tahoe City, Calif., from beneath a 1.9-m.y.-old volcanic flow. Pollen counts of four fossil samples are compared with soil-surface pollen samples from the Sierra Nevada. The presence of Picea (spruce) pollen in the fossil samples suggests that summer drought conditions in the central Sierra Nevada were less severe prior to...

Trachyscaphites pulcherrimus, described originally by Ferdinand Roemer in 1841 from fragments of nodose ammonites from Germany, is characterized by having five rows of tubercles on each flank of the phragmocone and three to five rows on each side of the body chamber. Weak midventral tubercles are present on some specimens. Ribbing is dense and usually...

This study was done in response to the shellfish industry's concern that bacteria in effluent from the national wildlife refuges along the northeast coast of the United States may be adversely affecting the harvest of shellfish. A line graph shows inconsistent relationships between bird population at the Montezuma refuge and total coliform, fecal coliform, and...

The generic names Archaeocycas and Phasmatocycas are introduced for two previously announced but unnamed new genera of Early Permian plants; these taxa are regarded as early stages in the cycadean lineage. The names arc formalized with diagnoses, illustrations, and type designations....

A relationship is established between fluorescent spectra obtained by using a light path through the liquid solution and the fluorescent spectra obtained by a direct reading of surface reflection (remote sensing). A brief review of quantum fundamentals provides the necessary information to conclude that "see-through" and reflectance spectra are identical in wavelength response. Many floating...

Six samples of group C eclogites from California and southwestern Oregon have initial Sr87/Sr86 ratios in the range of 0.7028 to 0.7051; Rb contents from less than 1 to 53.4 ppm; and Sr contents from 147 to 270 ppm. These data and major-element compositions suggest that the eclogites were derived from basalts older than but...

Stevens Type F water-level recorders have been modified to measure changes in the distance between two points, with amplification of up to 10 times. Such recorders are capable of measuring strains of 10-5 and possibly 10-6 over 10-m distances when corrections are made for frictional effects and temperature. In two...

The 9 February 1971 earthquake in the San Fernando Valley damaged the Lower Van Norman Dam severely enough to warrant draining the reservoir. In March 1972 the sediment deposited on the reservoir floor was examined to determine whether the 1971 earthquake had induced sediment deformation and, if so, what types....