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At least 847 records · Page 47Linked to original sources
USGS1976

Bog stratigraphy, radiocarbon dates, and Pinedale to Holocene glacial history in the Front Range, Colorado

Radiocarbon dates and stratigraphic cores from bogs, kettle ponds, and former ice-marginal lakes on the east and west sides of the Front Range, Colo., between lat 40°00' and 40°24' N. suggest that (1) valley glaciers of Pinedale age began to recede from their terminal positions between about 14,600 and 13,000 yr ago, (2) revegetation of glaciated areas at altitudes of 2,600-2,900 m (8,600-9,500 ft) was complete by 11,000-10,000 yr ago, (3) at one site, 3,500±1,000 yr elapsed before peat began to form after deglaciation, (4) the formation of bogs within the glaciated areas kept pace with glacier recession in a general way, beginning at progressively later times as deglaciation proceeded upward, (5) Pinedale glaciers had disappeared or were reduced to small remnants by about 8,000 yr ago, (6) moraines that have been mapped as belonging to the early stade of Pinedale Glaciation are no younger than 13,000 yr B.P. and may be older than 14,600 yr, and those delimiting what has been mapped as late stade are no younger than about 7,600 yr B.P. and are probably older than 7,800 yr, and (7) most of the till mapped as Pinedale was deposited between about 14,600 and 8,000 yr ago.

Colorado↗
USGS1976

The volumetric properties of H2O — A graphical portrayal

A graphical display of the volumetric properties of H 2 O is presented as density (0.01 to 1.0 g-cm -3 ) contoured on pressure-temperature coordinates and pressure (1-10,000 bars) contoured on density-temperature coordinates over the temperature range 0-1,000 °C. Data were obtained from sources published during 1964-1969; several minor inconsistencies are observed and attributed to inadequacies in the equations of state used to describe experimental data obtained above 1,000 bars.

Journal of Research of the U.S. Geological Survey↗
USGS1976

The heat capacities at low temperatures and entropies at 298.15 K of low albite, analbite, microline, and high sanidine

The heat capacities of low albite and analbite, NaAlSi 3 O 8 , and of microcline and high sanidine, KAlSi 3 Og, have been measured from 15 to 375 K using an adiabatic calorimeter. Tables of the thermodynamic functions C° p , (H° T –H° 0 )/T, (G° T –H° 0 )/T, and S° T –S° 0 are presented for these four feldspars from 0 to 370 K. At 298.15 K (25.0°C) the values for S° T S° 0 for low albite, analbite, microcline, and high sanidine are 207.4±0.4, 207.7±0.4, 214.2±0.4, and 214.2±0.4 J/(mol . K), respectively. The effect of the state of Al/Si order upon the heat capacity is quite small. The difference, ΔC° p , between albite-analbite and microcline-sanidine never exceeds 0.5 percent at temperatures below 400 K. With the exception of microcline, the heat capacities of these four feldspars follow a smooth S-shaped curve between 15 and 375 K, with no indication of transitions or anomalous behavior. Above 250 K, the heat capacity of microcline shows a form of thermal hysteresis. In the temperature range 250 to 375 K, the heat capacity of microcline is dependent upon its past thermal history. At 375 K, microcline which had been cooled to 230 K before the measurement of C° p has a heat capacity greater by approximately 1.2 percent than microcline which had not been previously cooled below 295 K. After a day of annealing at about 300 K, C° p of the previously cooled microcline decreases to essentially the same value as the microcline which had never been at a temperature below 300 K.

Journal of Research of the U.S. Geological Survey↗
USGS1976

Definitive X-ray powder data for covellite, anilite, djurleite, and chalcocite

By using the Guinier-Hägg focusing X-ray powder camera with Cr Kα 1 and Cu Kα 1 radiations, new powder data for covellite (CuS), anilite (Cu 7 S 4 , djurleite (Cu 1.934 S), and low chalcocite (Cu 2 S) have been obtained from synthetic and natural materials. The powder data were treated by least-squares analysis to obtain the best unit-cell parameters consistent with the data. These powder data are intended to replace inferior and incomplete data previously published and to serve as standards for the study of copper sulflde minerals.

Journal of Research of the U.S. Geological Survey↗
USGS1976

Flameless atomic absorption determination of bismuth in soils and rocks

Recent advances in flameless atomic absorption allow determinations of bismuth in concentrations as small as 50 ppb in 0.2 g of rock or soil sample. The sample is fused with sodium bisulfate and the fusion product is leached with hot 2 M hydrochloric acid and treated with ammonium citrate, (ethylenedinitrilo) tetraacetic acid disodium salt, and finally with ammonium 1-pyrrolidinedithiocarbamate to form a complex which is extracted into methyl isobutyl ketone. Aliquots of the latter are pipetted into a graphite furnace and then subjected to an established and automated program of drying, charring, and atomizing. Recorded peak heights provide a measure of the amount of bismuth present.

Journal of Research of the U.S. Geological Survey↗
USGS1976

Interstation correlation of peak-flow estimates

Equations are given for using the correlation coefficient between annual peaks at a pair of stream gaging stations to estimate the interstation correlation coefficient of estimated T -year peaks, computed standard deviations, and computed skew coefficients at the same pair of stations. The equations are based on statistics computed from samples of annual peaks simulated from normal distributions with built-in interstation correlation. The interstation correlation of 50- year peaks was found to be about equal to the square of the interstation correlation coefficient of the annual peaks.

Journal of Research of the U.S. Geological Survey↗
USGS1976

Reassessment of mercury in surface water in the Adirondack region, New York

A study in 1970 established a natural background concentration of mercury in surface water in the Adirondack region of New York. In 1974, new methods of sample preservation and analysis were used in determining concentrations of mercury of samples of water from the same surface-water sites sampled in 1970-71. Concentrations of mercury for all sites in the 1974 study were virtually the same as those obtained in 1970-71, less than 0.5 microgram per litre, which is the detection limit of the methods.

New York↗
USGS1976

Amino acids and gases in some springs and an oil field in California

Samples of water and gas were collected from six springs and two wells in the Upper Cretaceous Great Valley sequence and Franciscan Formation underlying the Coast Range of northern California and from four oil wells penetrating Tertiary sedimentary rocks in the Kettleman North Dome oil field. Comparison of the dissolved free amino acid compositions of the waters from the two locations show overlapping ranges with many more similarities than differences. The detection of nonprotein amino acids (sarcosine, β -amino n -butyric acid, and others) indicates the protein degradation is partly chemical rather than strictly biological. Other low molecular weight degradation products (methane, ethane, nonvolatile organic acids, and other organic chelating agents) were found. This may be one mechanism for the transportation of organic matter from the source rocks to the reservoir rocks of an oil deposit.

California↗
USGS1976

Solute transport and modeling of water quality in a small stream

An injection of chloride, sodium, and stable strontium was made at a constant rate for 3 hours into Uvas Creek, Santa Clara County, Calif., to determine the mass transport processes in a small stream. Five observation points were selected within a 610-metre reach of the stream below the injection site. Water samples were collected at the observation points during and immediately after the injection. A mathematical model of the stream was obtained by solving analytically and optimally the one-dimensional mass transport equation of the solutes in the stream. Comparison of field results with a simplified mathematical model indicates the dominance of convection in the behavior of sodium and chloride. The concentration of chloride and sodium can be closely simulated by the model. However, strontium cannot be well represented by the simplified model, which contains a first-order decay-type sink.

California↗
USGS1976

The measurement of adenosine triphosphate in pure algal cultures and natural aquatic samples

Three methods for the extraction of adenosine triphosphate (ATP) neutral dimethyl sulfoxide (DMSO), boiling tris buffer, and butanol-octanol extraction were equally effective on the alga Chlorella vulgwia . Dilution of extracted ATP samples was linear. Filtration of different volumes of samples resulted in proportional values for ATP in the extracts. Measurement of activity by either peak height or integration of the area under the peak were equally sensitive and reproducible. The assay of ATP sample was inhibited by mercuric chloride > cadmium chloride > calcium chloride > potassium or sodium phosphate, and by high concentrations of the extractant DMSO. Analysis of ATP in aquatic environments led to the problem of transferring a sample from the field to the laboratory without obtaining a change in ATP concentration. Membrane filtration of the sample followed by chilling at 4°C, slow freezing at 20° C, or freezing on dry ice were ineffective in maintaining a constant level of ATP. Chilling caused a marked increase in ATP, whereas slow freezing caused a significant loss of ATP. Freezing on dry ice was variable but generally resulted in large losses of ATP. Quick freezing by immersion of filter and algae in liquid nitrogen and storage on dry ice maintained a constant ATP level. Field extraction of the ATP followed by quick freezing in an acetone-dry-ice bath maintained the ATP in a convenient and stable form.

Journal of Research of the U.S. Geological Survey↗
USGS1976

Determination, storage, and preservation of low molecular weight hydrocarbon gases in aqueous solution

A gas chromatograph with a flame ionization detector was used in conjunction with a stripping chamber and cold trap apparatus to measure microgram-per-litre quantities of low molecular weight hydrocarbon gases in water samples. Glass bottles with ground-glass stoppers were used to store the samples. Formalin was added to stop bacterial activity and preserve samples with no measurable losses for as much as 7 days.

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

Ancient solution phenomena in the Madison Limestone (Mississippian) of north-central Wyoming

A karst topography was developed on the Madison Limestone of north-central Wyoming during the middle Meramecian early Chesterian time interval. Ancient karst features include enlarged joints, sinkholes, caves, and solution breccias that resulted from leaching of evaporitic beds in the upper 400 ft of the Madison bedrock. These features are predominantly phreatic rather than vadose. Most of the open spaces are fdled by sand and residual products reworked by the early Amsden sea, which transgressed the area during the Chesterian.

Wyoming↗
USGS1974

Dendritic dry valleys in the cone karst of Puerto Rico

The depressions in the cone karst (Kegelkarst) of the area west of Ciales in the Lares Limestone are alined in dry valleys that have dendritic patterns. These valleys apparently record the former existence of a cover of noncalcareous clastic material that was deposited on the limestone in late Tertiary time. One system of dendritic dry valleys ends at an abandoned meander of the Rio Grande de Manati, which is about 60 m above the present floor of the river. Another system leads to large masses of "blanket sand" near the town of Florida. These valleys were apparently eroded during the late Pliocene or very early Pleistocene when sea level was at least 80 m higher than it is today.

Puerto Rico↗
USGS1974

Classification and new genera of noncystimorph colonial rugose corals from the Onesquethaw stage in New York and adjacent areas

A. proposed classification is outlined for 39 species of colonial rugose corals in 10 genera belonging to the families Stauriidae, Craspcdophyllidae (including Cylindrophyllinae new subfamily and Craspedophyllinac), Disphyllidae?, and Zaphrentidae, from the Onesquethaw and lower Cazenovia Stages in New York and adjacent areas. These corals are described or redescribed in another report now in press. Three new genera, Asterobillingsa , Grewgiphyllum , and Cyathocylindrium , are described in this report.

New York, Ontario↗
USGS1974

Thermal conductimetric determination of submilligram amounts of total water in silicate and carbonate minerals

A simple and rapid method was developed for determining sub milligram amounts of total water in silicate and carbonate minerals. Powdered samples are fused by heating with sodium tungstate vanadium pentoxide flux in a Vycor combustion tube, and the evolved water vapor is absorbed on silica gel. After the water collection, the silica gel is heated at a controlled rate, and the released water vapor, carried by helium, is detected by thermal conductivity.

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

Preliminary study of rock alteration in the Catheart Mountain molybdenum-copper deposit, Maine

Studies of drill cores from the Catheart Mountain molybdenum-copper deposit indicate that the deposit is of the porphyry type. Hydrothermal alteration and sulfide mineralization are probably distributed in complex but systematic alteration zones. Most or all mineralization at Catheart Mountain is in a medium-fine-grained quartz monzonite enclosed within a larger mass of Attean Quartz Monzonite; no ore and little hydrothermal alteration have been seen in the Attean. Much of the ore and hydrothermal alteration seem to be and presumably are spatially related to irregular intrusive masses of porphyry. Only certain porphyry intrusives are mineral bearing, however, and many have no associated ore and alteration. Studies of hydrothermal alterations in surface exposures supplemented by rock analyses of bulk samples indicate that alteration features and sulfide zone characteristics of an area northwest of the mountain crest are, when measured against accepted porphyry models, very favorable for the occurrence of ore. Even though this favorable area has already been tested by some drilling, the presence together here of the strong center of potassic enrichment, the well-developed pyrite zone, and the strong and extensive phyllic alteration suggest that some further evaluation may be warranted.

Maine↗
USGS1974

Distribution of copper in biotite and biotite alteration products in intrusive rocks near two Arizona porphyry copper deposits

Biotite and its alteration products (primarily chlorite) from igneous rocks around the Ray and Esperanza (Esperanza-Sierrita) porphyry copper deposits, Arizona, were analyzed for copper by electron microprobe. The copper occurs in amounts >90 p/m (limit of detection) in most of the chlorites analyzed, is concentrated at the optical and chemical boundary of chlorite and biotite, and is not associated with sulfur. Most unaltered igneous and hydrothermal biotites analyzed contain <90 p/m Cu, and except for one sample, all copper that was detected can be explained as contamination by copper from chlorite grains. The paucity of detectable copper in igneous and hydrothermal biotite and its presence in daughter chlorite suggest that the positive association noted by some workers between the proximity of an ore deposit and the copper content of biotite might be partly the result: of increased amounts of chloritization of biotite near a deposit coupled with difficulty in physically cleaning the biotite separates. Additionally, previous speculations that (1) part of the copper in a deposit may come from altered biotite, and (2) copper in biotite indicates how copper behaves in a differentiating magma, are of doubtful value if based on data derived from analyses of bulk mineral separates.

Arizona↗