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The relations between geology and earthquakes remain mostly enigmatic in North America east of the Rocky Mountains. Hypocentral depths and the dips of rupture zones (preferred nodal planes) are among the seismological variables most likely associated with geologic structure in the stable continental region (SCR) of central and eastern North...

We captured 2,182 mallards (Anas platyrhynchos) in eastcentral Arkansas and marked 730 with standard bands, 728 with 10 reward bands, and 724 with 'dummy' radio transmitters during November 1986-89 to estimate band reporting rates in the Mississippi Alluvial Valley (MAV). Assuming all transmitters were reported, reporting rates were 0.16 (SE=0.049)...

Tundra swans (Cygnus columbianus) of the eastern population were neckbanded in Maryland, North Carolina, and Alaska from 1966 through 1990. These swans were resighted and recaptured during autumn, winter, and spring, 1966-1990. Although the original motivation for this study involved swan movements, we wanted to use the resulting data to...

In reply to the Critical Comment of R. K. Stoessell (this issue), limiting activity coefficients of bromide in halite (γNaBr) have been calculated by least-squares fitting of Simons et al.'s (1952) bromide distribution coefficient data for the Na(Cl,Br)-NaOH-H2O system at 35°C. Regular and subregular solidsolution model fits give γNaBr...

The August 4, 1985, Kettleman Hills earthquake was the third in a sequence of moderate shocks to occur beneath the northern half of a 110‐km‐long fold chain bounding the eastern California Coast Ranges. The 1982 MW =5.4 New Idria, 1983 MW=6.5 Coalinga, and 1985 MW=6.1 Kettleman Hills events define a southward...

A seismic refraction/wide‐angle reflection survey for the Trans‐Alaska Crustal Transect program reveals a thin, reflective crust beneath the southern Yukon‐Tanana terrane (YTT) in east central Alaska. These data are the first detailed refraction survey of the southern YTT and compose a 130‐km‐long reversed profile along the Alaska...

Upward-pointing shatter cones in sandstones of uncertain age (Middle Proterozoic? to Lower Cambrian?) and older crystalline basement rocks are exposed over an area of approximately 25 × 8 km in southwestern Montana. These shatter cones, together with pseudotachylites and breccias of various types (particularly in basement gneisses), are inferred to...

The Goat Rock and associated Bartletts Ferry fault zones, which mark the eastern margin of the Pine Mountain Grenville basement massif, are controversial due to the suggestion that they are rare exposed segments of the late Paleozoic southern Appalachian master decollement. The controversy in part stems from reported middle Paleozoic...

No abstract available....

The number of subspecies recognized in Hirundo pyrrhonota Vieillot (Cliff Swallow) from Alaska, Canada, and the northern contiguous United States ranges from one (Peters 1960) to three (e.g., Jewett et al. 1953, Oberholser, 1920, breeding from central Alaska to the central Great Basin, and two disjunct populations of nominate pyrrhonota,...

Like many granites, the Late Cretaceous intrusives of the eastern Mojave Desert, California, have heretofore provided useful but poorly focused images of their source regions. New studies of lower crustal xenoliths and inherited accessory minerals are sharpening these images.Xenoliths in Tertiary dykes in this region are the residues of an...

Electrophoretic differences at 15 presumptive loci were used to assess allelic frequencies, heterozygosities, and polymorphism for male Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) collected in east-central Alberta, north-central North Dakota, and east-central South Dakota. Five loci were polymorphic and mean heterozygosities ranged from 0.119 to 0.133. Significant differences were detected among these...

Grizzly bear (Ursus arctos horribilis) females with young occupied a greater proportion of area east of Yellowstone National Park during 1980-1989 compared to 1973-1979. Occupancy by all bears and females with young was lower in all peripheral areas compared to the Park, but greater east and south compared to north...

Like many granites, the Late Cretaceous intrusives of the eastern Mojave Desert, California, have heretofore provided useful but poorly focused images of their source regions. New studies of lower crustal xenoliths and inherited accessory minerals are sharpening these images.Xenoliths in Tertiary dykes in this region are the residues of an...

The upper Middle Jurassic-Lower Cretaceous Gravina belt lies along the eastern margin of the Alexander terrane in southeastern Alaska. This group of turbidites and mafic to intermediate volcanic rocks was deformed during mid to Late Cretaceous time during the closing of a basin of unknown size between the Alexander terrane...

Geophysical and subsurface geologic data suggest that the Avak structure, which underlies the Arctic Coastal Plain 12 km southeast of Barrow, Alaska, is a hypervelocity meteorite or comet impact structure. The structure is a roughly circular area of uplifted, chaotically deformed Upper Triassic to Lower Cretaceous sedimentary rocks 8 km...

The purpose of this study was to determine if there is a correlation between measurements of organic matter (OM) maturity and laboratory measurements of visible and near-infrared spectral reflectance, and if Landsat Thematic Mapper (TM) images could be used to map maturity. The maturity of Mississippian Chainman Shale samples collected...

The Uncompahgre caldera, and the Lake City caldera nested within it, each have fossil hydrothermal systems and associated mineral deposits that formed during multiple episodes of mineralization during Oligocene and Miocene time. New lead isotopic analyses for 51 ore samples, mainly galena, combined...

A Late Pleistocene volcanic ash couplet consisting of a Glacier Peak ash layer and an underlying Mount Saint Helens J ash layer has been identified at three sites in the Colville Valley area of northeastern Washington. This ash couplet has been reported as far east as northwestern Montana and therefore...

The hydrology of Cave Springs, the second largest spring in East Tennessee was investigated from July 1987 to September 1989. Wells near the spring supply about 5 million gallons per day of potable water to people in Hamilton County near Chattanooga. Discharge from the spring averaged about 13.5 cubic feet...

A major earthquake struck the Mojave Desert region in southern California at about 5 a.m. local time on June 28th, 1992. Seismologists located the epicenter of the magnitude 7.6 (Ms) earthquake 5-10km southwest of Landers, a small community about 150km east of Los Angeles. the earthquake shook a wide area...

Faulting associated with the June 28, 992, earthquake near Landers, California, broke the surface of the ground over a length of more than 70 km, the longest surface rupture in the United States since the great San Francisco quake of 1906. the strongest shaking associated with this magnitude 7.6 (MS)...

In conjunction with the U.S. Geological Survey's exploration program in the National Petroleum Reserve, Alaska (NPRA) several high-resolution temperature logs were made in each of 21 drillholes between 1977 and 1984. These time-series of shallow (average 600-m depth) temperature profiles were extrapolated to...

Inferring the frequency and magnitude of past earthquakes from the stratigraphy in exposures of normal-faulted sediments is difficult because colluvial lithofacies assemblages adjacent to faults are complex. Similarities in facies assemblages adjacent to young fault scarps in arid to semiarid areas, such as...

Large regions of the North American mid-continent are underlain by Precambrian layered rocks buried beneath Phanerozoic sedimentary strata. South of the Wichita Mountains, published seismic reflection profiles show a Precambrian layered assemblage extending for at least 40 km in both the north-south and east-west directions, and industry data show that...