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At least 1,063 records · Page 59Linked to original sources
USGS1974

Comparison of bacterial and phytoplankton populations under natural and laboratory conditions

Bacteria and blue-green algae were isolated from Oneida Lake, N.Y., and other sources. The blue-green algae Anabaena flos-aquae , Anabaena spiroides , Gloeotrichia echinulata , and Microcystis aeruginosa were grown under laboratory conditions and were separated into unialgal cultures. The bacterial population living in association with the unialgal blue-green algae differed significantly from the bacterial flora of Oneida Lake. Bacillus , Pseudomonas , Aeromonas , and Zoogloea were the most frequently occurring genera of bacteria from the lake, whereas Flavobacterium , Achromobacter , and Pseudomonas were the most common bacteria isolated from laboratory blue-green cultures. Nutritional and physiological characteristics of bacteria isolated in the laboratory were more uniform than those isolated from the lake.

Journal of Research of the U.S. Geological Survey↗
USGS1974

Distribution of chlorinated hydrocarbons in stream-bottom material

Six stream-bottom samples, contaminated in situ with high levels of chlorinated hydrocarbons, were size graded and the separates were analyzed. The contaminants were found distributed throughout the sample. The complexity of bottom-material samples is such that the distribution of chlorinated hydrocarbons may be controlled to a major extent by the organic matter and associated organisms. All particle-size fractions must be considered if representative samples are to be taken and quantitatively related to a stream.

Journal of Research of the U.S. Geological Survey↗
USGS1974

Calculated volumes of individual shield volcanoes along the Hawaiian-Emperor chain

Volume was calculated for the 107 individual volcanic shields along the Hawaiian Ridge Emperor Seamounts chain to help fulfill the need for volume data essential to determining eruption rates, fraction of mantle melted, and other parameters. Boundaries used were based principally upon location of rift zones related to each shield. Volcanic loci shown are modified from an earlier map to accommodate changes in bathymetry. Total volumes calculated for the Emperor and Hawaiian chains are 336.3 X 10 3 km 3 and 744.9 X 10 3 km 3

Hawaii↗
USGS1974

Stratiform chromitite at Campo Formoso, Bahia, Brazil

Serpentinized ultramafic rocks of pre-Minas age (Precambrian) crop out in an elongate belt 1 km wide and 15 km long on the west side of the Serra de Jacobina near Campo Formoso, Brazil. The original stratiform ultramafic body has been so metamorphosed, faulted, and eroded that only narrow dismembered segments occur along the thrust-faulted west side of the Serra de Jacobina. The most economically important segment is that near Campo Formoso where chromitite layers can be followed for about 8 km near the base of the intrusion. Three to five chromitite layers of minable thicknesses have been mapped, the thickest being 1.4 to 1.8 m. The aggregate thickness of chromitite is about 5 m and the average grade is about 43.5 percent Cr 2 0 3 . The Cr:Fe ratio ranges from 1.6:1 in weathered friable chromite to 3:1 in massive unweathered chromitite; in cleaned chromite concentrates the ratio is as much as 3.3:1. Estimates of indicated chromite ore reserves range from 16 to 20 million metric tons, of which only an estimated 6 million tons can profitably be mined. Factors preventing full exploitation of the chromite include (1) the local presence of as much as 7 m of overlying colluvium, (2) the extremely faulted character of the chromitite layers, (3) the presence of an overlying quartzite thrust plate very near the line of chromitite outcrops, and (4) the steep dips of the chromitite layers, 15° to 40° along the Pedrinhas-Limoeiro trends and 50° to 65° along the Cascabulhos trend.

Bahia↗
USGS1974

Detailed near-bottom geophysical profile across the continental slope off northern California

A geophysical profile was run across the continental slope off the California-Oregon border by use of a deeply submerged instrument package, approximately 50 m above the sea floor, containing a proton magnetometer and a 3.5-kHz transducer for shallow seismic penetration. Surface-towed seismic reflection equipment was operated concurrently. The deep-tow data show that the slope is relatively smooth; this agrees with interpretation of surface seismic profiles. Features smaller than 1 km in length can be resolved with the deep profiles but not with the surface profiles. The deep profiles show smallscale undulations less than 0.5 km long that are especially well formed on the steeper parts of the slope. These undulations may be caused by minor downslope movement of surface sediment or by depositional processes. The deep-tow and surface seismic profiles can be combined to give a more accurate structural picture of the continental slope than can be obtained with surface data alone.

California↗
USGS1974

Mineralogical studies of the nitrate deposits of Chile IV. Brüggenite, Ca(IO3)2-H2O, a new saline mineral

Br ü ggenite, Ca(I0 3 )2 - H2 0, is found in veins of high-purity soda niter in rhyolite tuff at Pampa Pique III, Oficina Lautaro, Chile, as long columnar anhedral crystals, as prismatic crystals, and as irregular anhedral crystals or encrusting masses. The mineral is colorless to bright yellow, and transparent to translucent, has vitreous luster and a hardness of about 3 1 / 2 , is brittle, and has conchoidal fracture. It is biaxial and has variable optic angle and refractive indices, which were determined by the spindle-stage method. Refractive indices are as follows: n α =1.772-1.779, n β =1.795-1.802, and n γ =1.817-1.824 (all ± 0.003); optic angle shows a range of 2 V Z = 86°-96°; Z = b and X ∧ c = -47°; dispersion (Z) is r < v , moderate. Brüggenite is monoclinic, space group P 2 1 / c , with a=8.509±0.001 A, b = 10.027±0.002 A, c = 7.512±0.001 A, β = 95°16.00'±0.55', volume 638.2 A 3 , Z = 4, G (calc) = 4.244, G (meas) =4.24±0.01. The X-ray diffraction powder pattern of brüggenite has the following strong lines ( hkl , d hkl 1 ): 031, 3.051 A (100); 220, 3.238 A (90); 200, 4.235 A (80); 002, 3.739 A (60); 012, 3.503 A (60); 231, 2.522 A (60). The composition was confirmed by chemical analyses.

Antofagasta Province↗
USGS1974

The association of geochemical anomalies with a negative gravity anomaly in the Chief Mountain-Soda Creek area, Clear Creek County, Colorado

Geochemical studies in the Chief Mountain Soda Creek area, Clear Creek County, Colo., show that anomalously high amounts of Au, Ag, Pb, Zn, Cd, and Bi in mull ash, and Cu and Hg in soil, correspond to a negative gravity anomaly in the Front Range mineral belt. The correspondence of the geochemical anomalies to the negative gravity anomaly suggests the presence of altered and mineralized rock and a Tertiary intrusive body at depth. This gravity anomaly and other similar gravity anomalies in the Front Range mineral belt merit further investigation for possible ore deposits.

Colorado↗
USGS1974

Generalization of stream travel rates and dispersion characteristics from time-of-travel measurements

Prediction of travel rates of water in streams is important for pollution control and for warning systems where contaminant spillage is possible. A method of estimating traveltime and dispersion of solutes in streams where such data are not available is provided in this report. Generalized relations for travel rates and dispersion indices as functions of stream-channel and discharge characteristics are developed using available time-of-travel data and the multiple-regression technique.

Journal of Research of the U.S. Geological Survey↗
USGS1974

The Sargent-Berrocal Fault Zone and its relation to the San Andreas Fault system in the southern San Francisco Bay region and Santa Clara Valley, California

The Sargent-Berrocal fault zone is a belt of thrust faults extending for about 58 mi (94 km) southeastward from the vicinity of Los Altos to San Juan Bautista, Calif. The fault zone generally dips southwestward toward the adjacent San Andreas fault at low to steep angles, and the southwest block has moved upward and northeastward. Thrusting across the fault zone has produced large-scale offset, which may increase to the southeast. If strike-slip movement has occurred, it has probably been minor. Offset Quaternary strata, physiographic features, and recent seismic activity all indicate that the Sargent-Berrocal fault zone has been active in the last one million years and that some clastic strain is currently being released along the northwest and southeast parts of the fault zone.

California↗
USGS1974

Investigation of diffusion in open-channel flows

This investigation examines the interrelation between turbulent diffusion, dispersion, and the statistical properties of turbulence in an open-channel flow. The results of the study substantiate Philip's concept relating the ratio of Eulerian to estimated Lagrangian time scales and the reciprocal of the longitudinal intensity of turbulence. The relation may be used to predict coefficients of longitudinal turbulent diffusion at the water surface and in the flow field, A similar concept using an integral scale based on the longitudinal intensity of turbulence may be used to predict coefficients of both surface and depth-averaged turbulent diffusion in three coordinate directions. Longitudinal space-time velocity correlation measurements can be used to predict the Lagrangian time scale only under limited conditions. Within the range of conditions studied, longitudinal diffusion accounted for 4 to 13 percent of the one-dimensional dispersion process.

Journal of Research of the U.S. Geological Survey↗
USGS1974

Upward migration of deep-well waste injection fluids in Floridan Aquifer, south Florida

Geochemical data from an industrial deep-well waste injection system southeast of Lake Okeechobee indicate a decrease in sulfate concentration concomitant with an increase in hydrogen sulfide concentration, a result of oxidation of injected organic waste by anaerobic bacteria. Subtle decreases in the sulfate-chloride ratio suggest that the waste migrated upward to a shallow monitor well about 27 mo after waste injection began and again within 15 mo of the resumption of waste injection after the injection well was deepened. The possibility of a hydraulic connection between the injection zone and overlying monitoring zone is implied. The decrease in the sulfate-chloride ratio appears to be a sensitive indicator of waste migration. Potential conflicts exist in the use of the Floridan aquifer for waste disposal and subsequent use as a natural resource.

Florida↗
USGS1974

Correlation of uppermost Precambrian and lower Cambrian strata from southern to east-central Nevada

Study of exposed uppermost Precambrian and Lower Cambrian strata in southern and east-central Nevada and intervening areas indicates that the Johnnie Formation of southern Nevada and the McCoy Creek Group (restricted) are correlative. In detail, the uppermost units of both sequences, the Rainstorm Member of the Johnnie Formation and the Osceola Argillite (and the equivalent unit G) of the McCoy Creek Group, arc lithologically similar and also considered correlative. Both are characterized by pale-red or purplish-medium-gray siltstone with abundant bedding-surface markings, and both contain scarce to abundant amounts of evenly or lenlicularly laminated limestone or silty limestone. Both units are lithologically unique in their respective areas of occurrence, and both are known to be widely distributed. Several thousand feet of dominantly detrital rocks occur above the Johnnie Formation in southern Nevada and the McCoy Creek Group in east-central Nevada. These detrital rocks consist of quartzite and siltstone in southern Nevada (the Stirling Quartzite, Wood Canyon Formation, and Zabriskie Quartzite) and dominantly quartzite (the Prospect Mountain Quartzite) in cast-central Nevada. Study in areas between southern and east-central Nevada indicates that the Stirling, Wood Canyon, and Zabriskie Formations change facies to the north and become lithologically similar to one another. The Prospect Mountain Quartzite of east-central Nevada is believed to be the final result of the facies change. It is equivalent to the combined Stirling, Wood Canyon, and Zabriskie of southern Nevada.

California, Nevada↗
USGS1974

Preliminary findings of a leachate study on two landfills in Suffolk County, New York

Plumes of leachate-enriched ground water extend 10,600 and 5,000 ft (3,200 and 1,500 m) downgradient from landfills in the towns of Babylon and Islip, respectively, and extend vertically beneath the landfills to the base of the upper glacial aquifer, whose thickness ranges from 71 to 77 ft (22-24 m) at the Babylon site and is 170 ft (52 m) at the Islip site. The Babylon and Islip landfills were started in 1947 and 1933, respectively. The quantities of ground water in the plumes are 2X10 9 gal (8X10 6 m 3 ) at Babylon and 1X10 9 gal (4X10 6 m 3 ) at Islip. Differences in quantity of water in the plumes and length of the plumes may result partly from a slower rate of refuse accumulation at Islip than at Babylon; however, the rate of travel for the front of the Islip plume is considerably less than the prevailing groundwater velocity would indicate. Distance traveled by the front of the Islip plume was roughly one-third the distance indicated by the calculated minimum ground-water velocity and may result from greater vertical travel distance in the upper glacial aquifer at Islip. Concentrations of HCO 3 - , Cl - , and SO 4 - 2 in the leachate-enriched ground water are higher than those in ambient ground water. Concentrations of Fe and Mn in the plumes are as much as 400,000 μ g/1 and 200,000 μ g/1, but concentrations of other metals, including Zn (220 μ g/1), do not exceed the U.S. Public Health Service drinking-water standards. The concentration of NH 4 + , the predominant nitrogen species in plume water, is usually more than 10 percent of the total cations in plume water and is greater than NH 4 + concentrations in ambient ground water; concentrations of NO 3 - in plume water are less than those in ambient ground water at Babylon and at some locations in Islip.

New York↗
USGS1974

New evidence on the age of the top of the Madison Limestone (Mississippian), Bighorn Mountains, Wyoming and Montana

The youngest strata recognized in the Madison Limestone arc dated by foraminifers and corals at two localities on the west flank of the Bighorn Mountains in Wyoming and Montana. Fossils collected in situ from the Madison at Shell Canyon represent Zone 12 of Mamet and Skipp of late Salem age (middle Visean), previously thought to be unrepresented by strata in the northern Cordilleran region of the United States. A block of residual chert found at Devils Canyon contains fossils with a possible age range of microfaunal Zones 12 15 (late Salem to Ste. Genevieve, middle to late Visean), providing further evidence of an extended age range for Madison strata prior to post-Madison, pre-Amsden erosion.

Montana, Wyoming↗
USGS1974

Strain-gage measurements in Carlsbad Caverns, New Mexico

Displacement transducers installed on a near-vertical joint in the lunchroom in Carlsbad Caverns measured small movements along the joint with a resolution of 3.7X 10 -6 in (9.4X10 -6 cm). During 1973 the maximum annual displacement horizontally, vertically, and perpendicularly to the plane of the joint was 4.7X10 -4 , 4.0X10 -4 , and 1.1X10 -4 in (1.2X10 -3 , 1.0X10 -3 , and 2.8X10 -4 cm), respectively.

New Mexico↗
USGS1974

Chert derived from magadiite in a lacustrine deposit near Rome, Malheur County, Oregon

Nodules and thin beds of chert occur in the upper part of the informally named Rome beds, about 8 11 km southwest of Rome, Oreg. The chert is in green to gray mudstone, about 8 m beneath a conspicuous gray and yellow zeolitic tuff. The bedded chert contains molds of saline minerals and it grades southward and marginward into nodular chert. The nodular chert is of two varieties: relatively large lobate nodules that have greenish-brown interiors and abundant saline crystal molds, and relatively small lobate nodules that have gray interiors and a surface reticulation. The latter variety is the so-called snakeskin agate prized by lapidaries. Both nodular varieties characteristically have a thin white rind. The cherts are similar, if not identical, to cherts reported from Quaternary lacustrine deposits in eastern Africa and from Pleistocene to Jurassic lacustrine deposits in Wyoming. The Rome chert probably formed from a hydrous sodium silicate precursor such as magadiite during diagenesis. Magadiite is generally a primary precipitate from a highly alkaline lake which is capable of attaining a high concentration of silica in solution.

Oregon↗
USGS1978

Giant glacial grooves at the north end of the Mission Range, Northwest Montana

Giant glacial grooves both cut across and wrap around the north end of the Mission Range. Some of these grooves are straight, others crescentic, but all appear to be independent of stratigraphic units and of the gross structure of the range. They were seemingly localized by preexisting stream valleys whose original trends were determined by joints. The grooves are cut in bedrock, U-shaped in cross section, thickly veneered with till, and roughly parallel. Most range in length from 0.5 km to 3.5 km. Each groove maintains a uniform width, but widths range from about 50 in to 275 in. Depths of individual grooves vary widely, ranging from about 10 m to about 60 in. The grooves are probably contemporaneous in age, but their time of formation is uncertain; it seems to have been prior to late Pinedale time but after the pre-Bull Lake glaciations. Of the various interpretations offered to explain their origin, the one that appears to fit most of the facts suggests that those grooves at the northern tip of the mountains were carved by a lobe of the south-flowing Cordilleran ice sheet, whereas those farther south were likely formed by the westward deflection of a north-flowing Swan valley glacier.

Montana↗
USGS1978

Potassium-argon ages of basement rocks from Saint George Island, Alaska

Potassium-argon ages from basement granitic rocks that intrude serpentinized peridotite on St. George Island, Alaska, range from 50 to 57 million years, with an initial argon isochron age. interpreted as a minimum figure, of 52 ± 2 m.y. The age of the granitic rocks and their association with serpentinized peridotite near the continental margin, which apparently marks the site of a Mesozoic subduction zone, suggest that the position of the subduction zone shifted southward to the Aleutian Trench in early Tertiary time.

Alaska↗