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At least 937 records · Page 52Linked to original sources
USGS1975

Quantitative determination of dawsonite in Green River Shale by powder-sample X-ray diffraction; effect of grinding

In an effort to evaluate the method of quantitative analysis by X-ray diffraction as a means of determining dawsonite abundances in Green River" oil shale, we performed a series of grinding experiments. Weighed mixtures of dawsonite + quartz and dawsonite + quartz + shale were ground for preset lengths of time, and the following X-ray diffraction peaks were measured for intensity: dawsonite (110) at 15.6 2 θ and (211) (002) at 32.1° 2 θ , and quartz (100) at 20.9° 2 θ and (101) at 26.6° 2 θ . Heights and areas were measured. Intensity ratios were plotted as functions of grinding time with a calculated probable error. Intensity ratios generally decrease as grinding time increases. The intensity of the 15.6° peak, D 15.6° , is most affected, and the most drastic reduction occurs during the first 20 min of grinding. The D 32.1° peak is least sensitive to grinding but is subject to interference by other minerals in the shale. We conclude that the X-ray diffraction method is not well adapted to the routine quantitative determination of dawsonite in oil shale of the Green River Formation.

Journal of Research of the U.S. Geological Survey↗
USGS1975

Notes on the origin of Colluma Crater, Bolivia

Colluma Crater, on the semiarid Altiplano (high plain) of western Bolivia, is an oval structure having overall dimensions of 6.7 km by 6.0 km. The structure has two almost concentric cuestaform rims (the inner rim is 3.6 km by 3.1 km) composed of poorly consolidated clastic sediments that dip outward. The center of the crater is about 80 m below the maximum height of the rims and about at the altitude of the surrounding plain. Because of the double rim, the centripetal drainage, and the absence of volcanic rocks, this structure is considered a collapsed dome. We believe it was probably formed by the doming of lower Quaternary (?) sediments by a subjacent igneous intrusion, partial retreat of the magma, collapse of the central part of the dome, erosional etching of the two rims, and partial filling of the center by detritus from the walls. Evidence for origin by impact (nickel-iron materials, shock structures, ejecta, and so forth) is lacking or was unrecognized, but this mode of origin is not rejected at this time. Geophysical surveys are recommended to determine whether the structure continues in depth and if an igneous, plug is below the crater.

Colluma Crater↗
USGS1976

Factors affecting declining water levels in a sewered area of Nassau County, New York

Double-mass-curve analysis of ground-water levels in Nassau County, Long Island, N.Y., shows that the average-weighted ground-water levels in a 32-mi 2 (83-km 2 ) segment of a sewered area declined 11.8 ft (3.6 m) relative to an adjacent unsewered area to the east during 1953-72. Electric-analog-model analysis indicates that 4.9 ft (1.5 m) of the decline is due to pumping in nearby Queens County, west of the sewered area. Most of the remaining 6.9 ft (2.1 m) of the decline is due to sewering. Streamflow within the sewered area has also declined because of the lowered ground-water levels.

New York↗
USGS1975

K-Ar age of the Similkameen Batholith and Kruger Alkalic Complex, Washington and British Columbia

Twelve K-Ar age determinations from the Similkameen batholith and the contiguous Kruger Alkalic Complex, including seven newly reported here, range from 69.9 m.y. to 177.2 m.y. Ages of coexisting hornblende and biotite show discordancies ranging from about 72 m.y. to 106 m.y., with hornblende consistently showing the greater analytical age. The hornblendes, with one exception, show increasing analytical age with increasing potassium content and approximately fit a 191.0-m.y. 40 Ar (radiogenic )/K isochron. The isochron shows a negative intersection with the 40 Ar (radiogenic) axis, indicating partial argon loss. The large negative deviation from the isochron of one low-potassium sample suggests that the isochron is biased to older ages. If so, the Similkameen and Kruger rocks probably crystallized between roughly 177 m.y. and 191 m.y. ago. The discordancies between hornblende and coexisting biotite are attributed to argon loss during one or possibly more episodes of thermal metamorphism, the most recent of which was probably between about 50 and 70 m.y. ago. This bracket is based on the age of apparently unmetamorphosed sedimentary deposits containing detritus from the Similkameen and Kruger bodies and the analytical age of the youngest biotite.

British Columbia, Washington↗
USGS1976

Two-dimensional steady-state dispersion in a saturated porous medium

A previously developed analytical solution for two-dimensional dispersion is computed for various conditions. These results were then compared with solution of previously developed approximate models of transverse dispersion which were used to analyze experimentally derived concentration distribution. Comparison established that, whenever steady state was reached, the values of dispersion coefficient computed using the approximate expression agreed with values derived from exact expression and in addition allowed a quick computation of the parameter.

Journal of Research of the U.S. Geological Survey↗
USGS1975

Radiocarbon dates indicate rates of graben downfaulting, San Jacinto Valley, California

Recent radiocarbon dates for wood samples collected from three depths in San Jacinto Valley graben indicate active tectonic downfaulting during the past 42,000 yr. The flood plain of graded San Jacinto River, entering the valley from the southeast and leaving toward the west, serves as a reference datum across the graben. Depositional rates suggest that downfaulting averaged about 0.007 ft (2.1 mm)/yr from 42,000 to 15,270 yr B.P. and since 15,270 yr B.P. has increased to about 0.019 ft (5.8 mm)/yr.

California↗
USGS1976

A simplified slope-area method for estimating flood discharges in natural channels

Discharge of a stream may be computed from the slope of the water surface, the cross-sectional area, and an estimate of channel roughness. This, the slope-area method, is widely used to compute flood peak discharges from high-water marks. Reliability of a computed discharge depends largely on the roughness coefficient, which must be estimated. This paper shows that results of comparable accuracy can be obtained from area and slope alone in natural channels; a roughness coefficient is not needed because roughness and slope are related. The estimating equation and suggestions for application of the simplified method are included.

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

Development of a standard rating for the Price pygmy current meter

Fifty new Price pygmy current meters, 50 used Price pygmy meters with used rotors, 50 used Price pygmy meters with new rotors, and 26 used Price pygmy meters with straight uniform (nonbeaded) contact wires were rated individually in a towing tank. A standard rating of V =0.961 N +0.039 ( V =0.293 N +0.012), where V is the velocity in feet per second (metres per second) and N is the meter rotation in revolutions per second, was established for the group of new meters. Repeated ratings of two new meters showed that under the best rating conditions, the individual Price pygmy rating is repeatable to within 1 percent. The standard errors of velocities predicted using the individual ratings and the standard ratings were compared. The use of the standard rating resulted in statistically higher standard errors than the individual ratings for all groups of meters. However, the differences are a fraction of 1 percent higher and are not of concern for practical purposes. The individual ratings and standard rating for the used meters with new straight contact wires were found to be statistically similar to the ratings for the new meters. Continuation of the use of individual ratings of Price pygmy current meters is probably unnecessary with the implementation of precise standards in their manufacture, rating of a random sample, and use.

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

Stratigraphic relationships within the Baraga Group of Precambrian age, central Upper Peninsula, Michigan

Details of the stratigraphic section in parts of northern Michigan have been known for many years, but correlation of units between geographically separated areas has been partly speculative. Mapping in the Witch Lake quadrangle has filled the gap between well-studied areas of the Marquette trough and parts of Iron and Dickinson Counties and has helped to correlate units in the Baraga Group (Precambrian X). Iron-formations are important marker beds; because of their magnetic properties they can be traced with certainty through poorly exposed areas. The magnetic Fence River Formation is now known to be stratigraphically beneath the Bijiki Iron-formation Member of the Michigamme Formation but may be equivalent to the Greenwood Iron-formation Member which crops out in parts of the Marquette trough to the east The Hemlock Formation (volcanic) underlies the Fence River and has been traced from near its type locality in Iron County to the south flank of the Marquette trough. These relationships provide the key to understanding the lateral facies changes responsible for the stratigraphic complexities of the Baraga Group.

Michigan↗
USGS1974

Geometry and growth of the White Sands dune field, New Mexico

Recent studies of the cores from four drill holes at the White Sands dune field in New Mexico demonstrated that the eolian sand body below the present active dunes ranges in thickness from 23 to 34 ft in the area tested. It consists of one to two older generations of dune and associated interdune deposits, which rest on playa and fluvial deposits. Relatively thick sheets of clean, well-sorted dune sand are separated from one another by thin zones of darker colored interdune deposits. In vertical sections of test trenches and in cores, these interdune deposits appear as thin zones of tan or buff, poorly sorted, subparallel strata between relatively thick units of white cross-stratified sand. The interdune deposits are buried by the advancing foresets of the encroaching dunes and their thickness is limited by the time of exposure. The subsurface dune deposits are relatively thin as compared to the active surface dunes. This difference in thickness apparently results from the beveling or truncation of dunes by the migration of interdune areas.

New Mexico↗
USGS1976

Epifauna at Jackson Point in Port Valdez, Alaska, December 1970 through September 1972

A biological sampling program at Jackson Point in Port Valdez, Alaska, was begun in December 1970. Sixteen artificial substrate samplers (8 multiplate and 8 rock-fllled baskets with net liners) were retrieved after 2 to 4 months' exposure. The most common groups in order of their abundance were Copepoda, Foraminifera, Nematoda, and Ostracoda during winter; Copepoda, Nematoda, Cirripedra, and Foraminifera, during spring; Pelecypoda, Amphipoda, Insecta, and Cirripedia during summer; and Pelecypoda, Copepoda, Insecta, and Nematoda during fall. The most abundant species collected during the study were the blue mussels ( Mytilus edulis ), copepods ( Harpacticus sp.), midges ( Clunio sp., Ghironomidae), and fairy shrimp (unidentified amphipods). During the summer and fall of 1972 the total number of epifaunal organisms was 22 times greater than during the same period in 1971, with Mytilus edulis comprising 88 percent of the community in 1972 (more than triple the percentage for 1971). The two sampler types collected approximately the same major groups of organisms; however, the multiplate samplers collected an average of 1.6 times more organisms than the basket samplers. The basket sampler, on the other hand, collected three more species per sample than did the multiplate samplers, resulting in species diversities 0.3 to 0.6 greater than those of the multiplate samplers. Diversity values were lower during 1972, except for the spring sample. Seasonal diversity varied from a low of 0.36 in the summer of 1972 to a high of 3.99 in the fall of 1971.

Alaska↗
USGS1975

A proposed glacial history of the Henrys Lake Basin, Idaho

Deposits of several glaciations from oldest to youngest, pre-Bull Lake, Bull Lake, and Pinedale are in and near the Henrys Lake basin, a northwest-trending hourglass-shaped trough in southeastern Idaho. Glacial deposits of pre-Bull Lake age are represented by till remnants confined mostly to the higher levels of the surrounding mountains. The extent of Bull Lake ice into the basin is uncertain. Glacial deposits and ice-marginal features suggest that a lobe of Bull Lake ice the Henrys Lake ice lobe moved into the basin and advanced as far north as the north edge of Henrys Lake. After this lobe melted back far enough to expose the north end of the basin, melt waters, chiefly from alpine glaciers in Targhee Creek and its tributaries, formed the broad low Howard Creek fan at the mouth of the valley of Howard Creek. Shortly thereafter, a complex of channels was cut into the fan by periodic melt-water floods which flowed westward through Targhee Pass during the waste of another Bull Lake ice lobe which lay in the West Yellowstone Basin. Melt waters from various sources ponded to form a shallow lake in front of the wasting Henrys Lake ice lobe. Waters from this lake drained southwestward around the southwest flank of the lobe via an ice-marginal channel. Upon total melt of the ice lobe, the lake was drained, the ice-marginal channel was abandoned, and the waters resumed their pre-ice course to the southeast. During the interglaciation, prior to the onset of the Pinedale Glaciation, northward-flowing streams deposited a veneer of obsidian sand and gravel along the south edge of the basin. In Pinedale time, alpine glaciers formed in the high mountain valleys near the basin, but none advanced into the basin.

Idaho↗
USGS1976

Enhydra and Enhydriodon from the Pacific Coast of North America

Two lineages of the "crab-eating" otter Erihydriodon , from the Old World Miocene and Pliocene, are suggested by the fossil record. One appears to lead to the late Pliocene Enhydriodon sivalensis from Villafranchian-equivalent beds in India and can be characterized by the presence of a parastyle on P 4 and by the location of the protocone of this tooth, which is located as far lingually as is the hypocone. In the other lineage no parastyle is developed on P 4 , the anteroposterior length of the carnassial blade is progressively reduced while the transverse width is increased, and the protocone of P 4 remains in its primitive position anterolateral to the hypocone. The second lineage, insofar as it is known, seems to lead toward the living sea otter Enhydra , particularly so because of the evolutionary direction shown by two species of Enhydriodon from the late Miocene and late Pliocene of California.

Pacific Ocean↗
USGS1975

Recurrent geothermally induced debris avalanches on Boulder Glacier, Mount Baker, Washington

Avalanches of snow, firn and hydrothermally altered rock and mud have been released six times since 1958 from Sherman Peak, part of the crater rim south of the main summit of Mount Baker, Wash. The avalanches traveled nearly identical paths 2.0-2.6 km down Boulder Glacier on the east slope of the volcano. Debris from at least one past avalanche can be seen as a thin bed of acidic mud in the glacier terminus. Fumaroles. thermal springs, and areas of warm ground, some of which are subglacial, are concentrated in the crater and were mapped by aerial infrared thermography. The outgoing radiant flux per unit area from a cluster of infrared anomalies within 50-150 m of the avalanche source was estimated to be 319 W m -2 (7,620 μ cal cm -2 s -1 ) in November 1972, which is sufficient to account for observed ice perforations. In addition vapor emission, not apparent in thermography, was observed along the source margin after the avalanche of August 1973. The principal conditions that produce the avalanches are considered to be the large accumulation of snow and firn on top of hydrothermally altered clay-rich ground at Sherman Peak and the saturation near the ground-firn interface by melt water produced both by summer snow ablation and by geothermal emission. The periodic avalanches have a potential for impounding water in the crater in addition to ponded water already known to occur. Sudden release of impounded water could present a danger to the Boulder Creek valley below.

Washington↗
USGS1975

Mobilization of iron in water in the Magothy aquifer during long-term recharge with tertiary-treated sewage, Bay Park, New York

Tertiary-treated sewage (reclaimed water) has been recharged by well into the Magothy aquifer at Bay Park, N. Y., intermittently since 1968. The longest of 13 recharge tests, the subject of this report, lasted 84.5 days. This was sufficient time for the reclaimed water to reach an observation well 200 ft (61 m) from the recharge well. Although the iron concentrations of the reclaimed water and the native water were less than 0.4 mg/l, the iron concentrations of samples from observation wells 20, 100, and 200 ft (6, 30, and 61 m) from the recharge well at times approached 3 mg/l. Source of the ii'on is pyrite that is native to the aquifer.

New York↗
USGS1976

Mississippian history of the northern Rocky Mountains region

The Mississippian history of the northern Cordilleran region of the United States consists of two principal depositional cycles separated by a cycle of epeirogenic uplift and erosion. Each depositional cycle is divisible into phases that represent significant changes in depositional patterns. During Cycle I (early Kinderhookian-early Meramecian), predominantly carbonate and evaporite deposition took place on a broad cratonic shelf bordered on the east by land and on the west by a deep trough that received terrigenous sediments from an adjacent western landmass. Kinderhookian transgression was followed by regression during the Osagean and early Meramecian. Regional uplift during latest early Meramecian time (Cycle II) drained the shelf area and caused the sea to be confined to the western trough. During Cycle III (middle Meramecian-Chesterian), the sea again transgressed onto the craton, which was differentiated into the Big Snowy-Williston, Wyoming, and Uinta basins, where terrigenous and carbonate sediments were deposited. The Big Snowy-Williston basin was uplifted during latest Chesterian time and lost its identity, but the Wyoming basin continued to expand into the Pennsylvanian, when it engulfed most of the Cordilleran platform and breached the Transcontinental arch. Application of generalized carbonate, terrigenous, and evaporite depositional models results in specific models that explain the Mississippian depositional patterns.

Colorado, Idaho, Montana, Nebraska, Nevada, North ↗
USGS1975

Changes in concentration of certain constituents of treated waste water during movement through the Magothy Aquifer, Bay Park, New York

Approximately 7 million gallons (27 million litres) of tertiary-treated sewage (reclaimed water) was injected by well into the Magothy aquifer and was subsequently pumped out. As the reclaimed water moved through the aquifer, concentrations of certain dissolved constituents decreased as follows: Total nitrogen, 7 percent; methylene blue active substances, 49 percent; chemical oxygen demand, 50 percent; and phosphate, more than 93 percent.

New York↗
USGS1975

Norman Creek, a source of recharge to Maramec Spring, Phelps County, Missouri

Rhodamine WT dye was used to trace the subsurface movement of water from Norman Creek, a losing Ozark stream, to Maramec Spring, a straight-line distance of 8.7 mi (14.0 km). Grab samples and activated charcoal packets were used to check possible emergent points of the dye. The leading edge of the dye reached Maramec Spring 68-75 days after the dye injection, and the peak concentration reached the spring 82-93 d after injection. Small quantities of dye were still being recovered at the spring 114 d after injection and 39-46 d after the dye first arrived at the spring. Computed average velocities, assuming straight-line travel, are 0.47-0.42 ft(0.14-0.13 m)/min for the leading edge and 0.39- 0.34 ft(0.12-0.10 m)/min for the peak. This apparent rate of travel compares favorably with other recent subsurface tracing studies in southern Missouri which generally range from 0.4 to 25 ft(0.12 to 7.6 m)/min.

Missouri↗