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At least 901 records · Page 50Linked to original sources
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↗
USGS1978

Comendite (peralkaline rhyolite) and basalt in the Mitu Group, Peru: Evidence for Permian-Triassic lithospheric extension in the central Andes

The Mitu Group consists of generally coarse clastic strata and volcanic rock of Permian and (or) Triassic age filling elongate basins that parallel the general structural trend of the Peruvian Andes. Volcanic rocks of the Mitu Group include peralkaline and nonperalkaline rhyolite and subalkaline basalt. To our knowledge, the peralkaline rhyolites are the first of this rock type reported from South America. The presence of appreciable volumes of peralkaline rhyolite and basalt, supports the interpretation that the Mitu Group was deposited in major graben structures that resulted from lithospheric extension produced by rifting or possible backarc extension.

central Andes Mountains↗
USGS1978

Fusion of granodiorite by basalt, central Sierra Nevada

A trachybasalt plug, 100 m in diameter, has partially fused inclusions and wallrock of porphyritic granodiorite near Tuolumne Meadows, Yosemite National Park, Calif. Granodiorite surrounding the plug was altered within distances of about 3.5 m. Within this distance, (1) trace amounts of glass occur along fractures and grain boundaries, (2) biotite has been altered from dark olive to dark reddish brown and contains bands of fine reddish iron oxide grains, and (3) optic axial angles of potassium feldspar decrease toward the contact. As much as 20 volume percent of glass occurs in the granodiorite in a reentrant and in inclusions within the plug. Detailed study of two partially fused samples shows that, relative to unfused granodiorite, SiO 2 is clearly depleted in both samples, whereas K 2 O is depleted in one but not the other. Total iron, Al 2 O 3 , MgO, Na 2 O, and H 2 O show apparent increases in both samples; other constituents show no significant changes. Chemical analyses suggest that much original material was lost from the partially fused rocks, probably by mass migration of melt rather than by chemical diffusion. The composition of glasses now present in the partially fused rocks was dominated by melting of quartz and feldspars, whereas the composition of the early-formed "lost" melt was strongly influenced by subsolidus reaction and subsequent melting of biotite.

California↗
USGS1978

Chabazite in siliceous tuffs of a Pliocene lacustrine deposit near Durkee, Baker County, Oregon

A relatively pure chabazite deposit of at least 75 X 10 6 metric tons occurs near the Durkee type locality of erionite. This erionite is in a welded tuff interbedded with lacustrine rocks- of a closed Pliocene basin. The zeolites, chabazite, erionite, clinoptilolite, and other authigenic silicate minerals are confined to a 27-square-kilometer area of altered rocks enclosed in relatively freshwater lacustrine beds. About 135 meters of the lower part of the 350-m stratigraphic section at the southeastern part of the lake basin contain zeolitic tuff. The chabazite is an early product of the reaction between glass of rhyolitic or dacitic composition and alkaline (pH>9) saline lake waters. Erionite, clinoptilolite, analcime, and potassium feldspar follow chabazite in the paragenetic sequence. At the erionite type locality, chabazite and clinoptilolite form megascopic crystal clusters within fractures and cavities in unaltered welded tuff. Elsewhere in the basin, most zeolite crystals in the altered airfall or reworked tuffs are less than 80 micrometers long. Chemical analyses, unit-cell determinations, and mean indices of refraction show that fine-grained chabazite varies in composition and physical parameters.

Oregon↗
USGS1978

Differentiation of the sulfides in the Basal Zone of the Stillwater Complex, Montana

Chemical leaching and analysis of the sulflde portion of rocks from a section of the Basal zone of the Stillwater Complex demonstrate that mole fractions of nickel, copper, cobalt, and sulfur in the sulfldes show trends and repeating patterns when plotted against stratigraphic position. These patterns are attributed to differentiation of immiscible sulflde liquids probably in response to differentiation of basaltic magma. Changes in composition of the immiscible sulflde liquids could most readily take place during the collection of the sulflde from the basaltic magma or during the crystallization of the sulflde liquid to the present assemblages of minerals.

Montana↗
USGS1978

Recognition of oxidized sulfide minerals as an exploration guide for uranium

The difference in color between tan to red oxidized sandstone and gray reduced sandstone on either side of the reduction-oxidation (redox) interface, which is- the locus of uranium concentration in roll-type deposits, has been noted and used locally as an exploration guide within known uranium districts. Reduced sandstone is characterized in many deposits by the presence of iron sulflde minerals (particularly marcasite and pyrite) that occur as replacements of and overgrowths on iron-titanium oxide minerals and plant debris and as cement of detrital grains. Oxidation of the sulfldes by oxygenated ground water forms yellow to red ferric oxide and ferric hydroxide phases ("limonite") that replace the FeS 2 minerals. Processes other than the oxidation of sulfldes, however, can cause reddening of clastic sediments without the creation of a redox boundary, and so color alone is not a sufficient condition by which to judge the potential for uranium ore in frontier areas. Ferric oxides that form by the oxidation of iron sulflde minerals can be distinguished from other forms of ferric oxide by reflection microscopic examination of polished grain mounts- and polished thin sections'. Diagnostic features of oxidized sulfldes are limonite pseudomorphs of sulfldes and limonite containing internal textures that mimic characteristic textures of previously sulfldized detrital phases. Recognition of oxidized sulfides by reflection microscopy, then, can distinguish oxidized sandstones, which might have a redox boundary downdip and which would therefore be favorable hosts for uranium concentration, from those without such potential.

Journal of Research of the U.S. Geological Survey↗
USGS1978

Discrimination of fluvial and eolian deposits by number-frequency analysis of sediments of sand through silt size from a point bar, Rio Puerco, New Mexico

Fluvial and eolian deposits are interbedded in ephemeral-stream, arid-region point bars in the channel of the Rio Puerco, west of Albuquerque, N. Mex. Number frequency distributions of grain size for both types of deposits were obtained using an electronic automatic image analyzer for a suite of 10 samples. The number-frequency results were superior to weight-frequency (sieve) results in discriminating between eolian units and fluvial units in a vertical point-bar sequence. The image-analysis technique also identified those fluvial deposits whose size distributions have been altered significantly by winds, as well as fluvial deposits that do not show a prominent eolian-process component.

New Mexico↗
USGS1975

An occurrence of disseminated uraninite in Wheeler Basin, Grand County, Colorado

Disseminated uraninite occurs in Wheeler Basin, Grand County, Colo., about 5 mi (8 km) southeast of Monarch Lake, in Precambrian metamorphic rocks consisting of migmatized gneiss and mixed gneiss and pegmatite. An intrusion of Precambrian Y Silver Plume Granite lies within 400 ft (122 m) of the occurrence. The disseminated uraninite is confined to parts of the host rock that are rich in biotite; highest grade found was 0.73 percent uranium. The disseminated uraninite occurs as cubes and grains, generally from 0.1 to 0.3 mm across. Unit cell edge of the uraninite, ≈ 5.48 A, suggests its pegmatitic origin. The origin of the uraninite disseminations is attributed by us to remobilization and concentration of elements during metamorphism caused by the intrusion of Silver Plume Granite. Uranium and lead isotopic analyses by K. R. Ludwig of uraninite and monazite from biotite concentrations confirm an apparent age of 1,450±20 m.y. for these minerals. This age is equivalent to that reported for the Silver Plume Granite. Although the Wheeler Basin occurrence is small in size, it has many similarities to the Rossing uranium deposit in South-West Africa.

Colorado↗
USGS1978

Spectral gradient of lunar radiobrightness: Heat flow or volume scattering?

Lunar heat flow cannot be derived unambiguously from the spectral gradient of the radiobrightness. Volume scattering of microwaves by rock clasts within the lunar regolith results in a spectral component in the 5- to 30-centimeter range of wavelengths that is a significant fraction of that resulting from lunar heat flow.

Journal of Research of the U.S. Geological Survey↗
USGS1978

Accuracy of flood mapping

Information taken directly from published and unpublished reports was used to appraise the accuracy and the limitations of the three general flood-mapping methods: detailed, historical, and physiographic. In the appraisal, the probable nationwide average standard error of estimate for water depth and elevation in percentage of depth and in meters was determined for 100-year flood boundaries. Bias errors, users' errors, and certain time-variant errors were not. considered. The probable standard error for the detailed method is 23 percent. Based on 3.9 m as the national average 100-yr depth, the probable standard error of estimate is 0.9 m. The detailed method is applicable to a wide range of hydraulic and topographic conditions; it is the only method tested that is directly applicable to floodways analysis. The method requires detailed data and time-consuming analyses, however, and it has only limited application for determining flood elevations for sheet flow and for flow in channels having readily movable boundaries. The probable standard error for the historical method is 23 percent. Based on the 3.9-m average 100-yr depth, the standard error is 0.9 m. The historical method is applicable to a wide range of hydraulic and topographic conditions if specific data are available. The method is not applicable to floodways analysis, and it has only limited application for flow in moveable-boundary channels. The standard error for the physiographic method is 27 percent. In meters, the error is 1.1. .The physiographic method is simpler to apply than the other methods; however, it can be used only in natural channels having rigid boundaries. It is not applicable to sheet flow and to floodways analysis.

Journal of Research of the U.S. Geological Survey↗
USGS1978

Definition of regional relationships between dissolved solids and specific conductance, Susquehanna River basin, Pennsylvania and New York

This report presents statistical tests for assessing the accuracy and validity of two regional models of the relationship between dissolved-solids concentration and specific conductance. These models are used to estimate dissolved-solids concentrations based on specific-conductance measurements. The two regional models are compared with station models for 27 stream sites in the Susquehanna River basin. The average standard errors of estimate of two regional models, when used to estimate dissolved-solids concentrations for the 27 stream sites, are 10.7 and 10.6 percent. In comparison, the station models have average standard errors of 9.0 and 9.3 percent, respectively. Results of the statistical tests indicate that in the Susquehanna River basin the regional models can be used to estimate dissolved-solids concentrations from specific-conductance data for sites for which chemical analyses are not available.

New York, Pennsylvania↗