Publications

Irregularities in the reconstructed gradients of latest Pliocene and Quaternary terraces in the northern Bighorn Basin, northwest Wyoming and south-central Montana, suggest that Quaternary movements have occurred on the Frannie anticline, the Nye-Bowler–Sage Creek fault zone, and the North Pryor fault. This area has been considered tectonically inactive. The timing of the interpreted movements is

No abstract available.

No abstract available.

Recognition of differences in the habitats, apparatuses, and ranges of Late Devonian Icriodus and Pelekysgnathus permits refinement of their biofacies interpretations and construction of an alternate icriodontid zonation. Icriodus is a euphotic genus that predominated in most environments during the early Late Devonian (Frasnian) but died out during the early Famennian. Its apparatus consists of p

Several methods for the analysis of remotely sensed reflectance data are compared, including empirical methods and scattering theories, both of which are important for solving remote sensing problems. The concept of the photon mean optical path length and the implications for use in modeling reflectance spectra are presented. It is shown that the mean optical path length in a particulate surface i

The spectral properties of water ice‐particulate mixtures are studied for the purpose of deriving the ice and particulate abundances from remotely obtained spectra (particulates referring to nonicy materials in the form of grains). Reflectance levels and ice absorption band depths are a complex function of the single scattering albedo of the particulates embedded in the ice. The ice absorption ban

Geochemical sampling and mine and prospect surveys identified small areas in the Laurel-McGee and Wheeler Ridge Roadless Areas in the eastern Sierra Nevada, California, that have probable potential for the occurrence of small deposits of tungsten and (or) base and precious metals. A number of mines and prospects in or near the roadless areas are in occurrences of one or more of the metals, tungste

Igneous rocks commonly have large magnetic susceptibilities so that high topographic relief in crystalline terrane can produce significant anomalies in aeromagnetic surveys. Topographic anomalies are particularly significant in relatively undeformed volcanic terrane because young volcanic rocks generally have large natural remanent magnetizations as well as large susceptibilities. These anomalies

No abstract available.

No abstract available.

Isotopic ratios and trace element abundances were measured on samples of Ir-enriched clay at the Cretaceous-Tertiary boundary, and in carbonate and marl from 5 cm below and 3 cm above the boundary. Samples were leached with acetic acid to remove carbonate, and with hydrochloric acid. Leachates and residues were measured. The Sr, Nd, O and H isotopic compositions of the boundary clay residues are d

U-Th-Pb analyses of zircons from an ortho-augen gneiss body in the Yukon-Tanana Upland of east-central Alaska yield strong evidence for the presence of early Proterozoic material in this area. U-Pb data define a chord that intersects concordia at about 2,300 and 345 m.y. We consider two interpretations: (1) the protolith was intruded during the Proterozoic and was subsequently metamorphosed in the