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Anticipated irrigation on sandy soils has prompted evaluation of ground-water supply potential in the Little Falls area. Geologic conditions cause ground-water availability to vary widely in the area. The largest and most readily available groundwater source is the glacial outwash sand and gravel from which the soils were derived. Test augering...

Embryonic development of lake herring (Coregonus artedii) was observed in the laboratory at 13 constant temperatures from 0.0 to 12.1 C and in Pickerel Lake (Washtenaw County, Michigan) at natural temperature regimes. Rate of development during incubation was based on progression of the embryos through 20 identifiable stages. An equation...

The thermal-feedback theory of mantle melting proposed by Shaw in 1969 is found to be quantitatively consistent with data pertaining to the evolution of the Hawaiian Ridge. Applicable rate factors are estimated from relations between lava volumes and position along the ridge given in this paper and the radio-metric age...

The 1959 eruption of Kilauea volcano is unique among recent Kilauea summit eruptions (1952 to 1968) in at least two respects: (1) a large collapse of Kilauea summit accompanied the eruption, and (2) the erupted lavas show a complex variation in their bulk chemical composition. Both features suggest that the...

Analyses of pore fluids from reducing environments demonstrate that reduction of SO4 is accompanied by large increases in alkalinity and strong depletion of Ca and Mg. The data are compatible with a model of replacement of Fe3+ in clay lattices by Mg from the interstitial solutions and the precipitation of...

The Mud Volcano area in Yellowstone National Park provides an example of a vapor‐dominated geothermal system. A test well drilled to a depth of about 347 ft penetrated the vapor‐dominated reservoir at a depth of less than 300 ft. Subsequently, 16 vertical electrical soundings (VES) of the Schlumberger type were...

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...

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...

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...

Karst regions of the world are characterized by limestones and other soluble rocks at or near land surface that have been modified by solutional erosion. Such surface features as sinks, long dry valleys, sparse streams, and bare rock and such subsurface features as caverns, arterial solution openings leading to large...

Chemical analyses of 167 typical specimens indicate that about 95 percent of the intrusive rocks of the central Sierra Nevada contain more than 79 percent normative Ab + An + Or + Qz. If the composition of the lower continental crust is similar to or slightly more felsic than andesite,...

Stable isotope and chemical relations have been determined in a typical epithermal Au-Ag deposit located in the Bodie mining district of California. Analyses were made of altered host rocks, vein minerals, alteration clays, fluid inclusions, modern spring waters, and unaltered rocks of the area.The results indicate that a hydrothermal convection...

Negative Bouguer anomalies (−80 mgals) near the Pacific coast of southern Colombia define the position of the Tertiary Bolívar trough. Values increase eastward to a huge positive anomaly (+75 mgals) over Mesozoic “eugeosynclinal” rocks of the western Andes. This anomaly is part of the West Colombian gravity high, which extends...

A bathymetric map based on new data allows examination of geomorphic features on the narrow continental margin off Liberia. The continental shelf in this region is relatively flat and featureless. The northwestern part of the continental slope, off Monrovia and Cape Mount, shows complex slump features and two submarine valleys. The central part of the...

A model for climatic change, and particularly for the changes of the late Cenozoic, involves as its primary variables the albedo of the earth and the heat storage characteristics of the oceans. Geography exerts a strong influence. The model proposed does not require metaphysical causes or astronomical events other than known variations in the earth's...

For reconnaissance geologic mapping and mineral resource evaluation of the Granite Fiords wilderness study area, we developed and used a system of machine-processable field notes. Preprinted field forms standardize notes and serve as checklists that insure collection of all available data. The use of this system cut in half the time required to record data...

Marine invertebrates from the Paso Robles Formation recently discovered near Atascadero, Calif., indicate that the basal part of this chiefly nonmarine deposit is of provincial early Pliocene age. Heretofore the lack of direct fossil or radiometric evidence of the age of the Paso Robles has made it a difficult unit to place in the...

Rocks of the Late Cretaceous composite Boulder batholith, though successively emplaced in a relatively small segment of the Earth's crust within a very brief time span (78 to 68 m.y.), can be grouped chemically into two magma series: (1) the main series, defined principally by plutons in the central and northern...

The sheetlike solution cavities that supply water to most wells in central Tennessee are 100 to 2,500 feet wide and less than 0.2 inch high. These dimensions have a scale similar to those in Hele-Shaw models. Both logical and mathematical evidence indicate laminar ground-water flow, except close to pumping wells....

Most sulfosalts may be regarded as intermediate phases on joins between simple sulfide components (e.g., all lead sulfbismuthinides lie on the PbS-Bi 2 S 3 join). Many of the structures are characterized by subunits whose individual structures are similar to those of the component simple sulfides (e.g., galena-like and stibnite-like layers in the lead...

Thirteen pairs of chemicals involving 18 pesticides and two polychlorinated biphenyl preparations were each fed for 5 days to Japanese quail or ring-necked pheasant chicks 7 to 16 days of age. Malathion + EPN, and malathion + trichlorofon were moderately synergistic in tests with both species, whereas joint toxicities of...

A large avalanche (21 square kilometers) at the Apollo 17 landing site moved out several kilometers over flat ground beyond its source slope. If not triggered by impacts, then it was as "efficient" as terrestrial avalanches attributed to air-cushion sliding. Evidently lunar avalanches are able to flow...

The early magmas of the northern Sierra Nevada, calc-alkaline andesite of island-arc type and its derivatives, all low in potassium, were generated during the Devonian(?) period, possibly along an eastward-dipping sub-duction zone. These magmas could have been derived from mantle peridotite of the continental plate by introduction of water from...

Apparent initial Sr87/Sr86 ratios of five ash-flow tuffs (0.7063 to 0.7139) and several mafic to silicic lavas (0.7055 to 0.7131) indicate that the magmas were derived below the base of the Precambrian granitic crust (0.7231 to 1.0906). Liquidus compositions in the system Q-Or-Ab-H2O and oxygen-isotope geother-mometry suggest that the silicic magmas...