November 17, 2014
Composition of dust deposited to snow cover in the Wasatch Range (Utah, USA): Controls on radiative properties of snow cover and comparison to some dust-source sediments
By Rich Reynolds (GECSC), Harland Goldstein (GECSC), Bruce Moskowitz, Ann Bryant, McKenzie Skiles, Raymond Kokaly, Cody Flagg, Kimberly Yauk, Thelma Berquó, George Breit, Michael Ketterer, Daniel Fernandez, Mark Miller, and Thomas Painter. Published in Aeolian Research.
This study provides the first comprehensive analyses of the particle-compositional causes of accelerated snow melt in the American West. It was found that goethite (an iron oxide mineral) and carbonaceous matter are the main influences on lowering snow-cover albedo on the basis of spectroscopic, magnetic, chemical, and electron microscopic methods. The results of this study will improve models that factor in effects of dust on snow-melt rates by providing snow hydrologists with new quantitative inputs.
November 13, 2014
Coastal tectonics on the eastern margin of the Pacific Rim: late Quaternary sea-level history and uplift rates, Channel Islands National Park, California, USA
By Dan Muhs (GECSC), Kathleen Simmons (GECSC), Randy Schumann (GECSC), Lindsey Groves, Stephen DeVogel, Scott Minor (GECSC), and DeAnna Laurel. Published in Quaternary Science Reviews.
Coastal California is very active tectonically and geomorphic expressions of this include uplifted marine terraces. In this study, the terraces on San Miguel Island and Santa Rosa Island were mapped and new age estimates were generated using uranium-series dating of fossil corals and amino acid geochronology of fossil mollusks. The study shows that uplift rates on these two islands are relatively low and similar to most other parts of southern California, challenging a recent study that suggested that uplift rates were extraordinarily high for this area.
November 12, 2014
Geologic map of the west-central Buffalo National River region, northern Arkansas
By Mark Hudson and Kenzie Turner. USGS Scientific Investigations Map 3314.
This 1:24,000-scale map summarizes the geology of the west-central Buffalo National River region in the Ozark Plateaus region of northern Arkansas. Along with the map sheets, this report provides a geologic map database of the map area that improves understanding of the regional geologic framework, its influence on regional groundwater flow systems, and the Quaternary history of landscape development.