Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 1441

Tectonic controls of Mississippi Valley-type lead-zinc mineralization in orogenic forelands Tectonic controls of Mississippi Valley-type lead-zinc mineralization in orogenic forelands

Most of the world's Mississippi Valley-type (MVT) zinc-lead deposits occur in orogenic forelands. We examine tectonic aspects of foreland evolution as part of a broader study of why some forelands are rich in MVT deposits, whereas others are barren. The type of orogenic foreland (collisional versus Andean-type versus inversion-type) is not a first-order control, because each has MVT...
Authors
D. C. Bradley, D. L. Leach

Tree-ring dated landslide movements and their relationship to seismic events in southwestern Montana, USA Tree-ring dated landslide movements and their relationship to seismic events in southwestern Montana, USA

To determine periods of incremental landslide movement and their possible relationship to regional seismic events, the tree-ring records of 32 titled and damaged conifers at three sites on landslides in the Gravelly Range of southwestern Montana were examined. Several signs of disturbance in the tree-ring record indicating landslide movement were observed. Commonly, the tree-ring record...
Authors
Paul E. Carrara, J.M. O’Neill

Pliocene to middle Pleistocene lakes in the western Great Basin: Ages and connections Pliocene to middle Pleistocene lakes in the western Great Basin: Ages and connections

No abstract available.
Authors
Marith C. Reheis, Andrei M. Sarna-Wojcicki, Richard L. Reynolds, C. A. Repenning, Martin D. Mifflin

Monitoring dust storms and mapping landscape vulnerability to wind erosion using satellite and ground-based digital images Monitoring dust storms and mapping landscape vulnerability to wind erosion using satellite and ground-based digital images

Wind-induced dust emission in the southwestern United States is important regionally because of its impact on human health and safety and its influence on ecosystem dynamics. Factors that control dust emission include wind velocity, sediment availability, and surface conditions (e.g., vegetation type and degree of cover, surface crusts and armoring, and soil moisture - Gillette and Passi...
Authors
Pat S. Chavez, David MacKinnon, Richard L. Reynolds, Miguel G. Velasco

An ENSO predictor of dust emission in the southwestern United States An ENSO predictor of dust emission in the southwestern United States

Here we show that there is a significant relationship between Nino 3.4 ENSO anomaly (Dec–Jan average) and precipitation in the southwestern United States. This contributes to increased frequency of dust events in the years following strong La Niña and El Niño years. High probabilities (60%–100%) exist for an elevated frequency of dust events in years when the ENSO anomaly, annual...
Authors
Gregory S Okin, Marith C. Reheis

Early Holocene change in atmospheric circulation in the Northern Great Plains: An upstream view of the 8.2 ka cold event Early Holocene change in atmospheric circulation in the Northern Great Plains: An upstream view of the 8.2 ka cold event

Elk Lake, in northwestern Minnesota, contains numerous proxy records of climatic and environmental change contained in varved sediments with annual resolution for the last 10,000 years. These proxies show that about 8200 calendar years ago (8.2 cal. ka; 7300 radiocarbon years) Elk Lake went from a well-stratified lake that was wind-protected in a boreal forest to a well-mixed lake in...
Authors
Walter E. Dean, Richard M. Forester, J. Platt Bradbury

Progress in global lake drilling holds potential for global change research Progress in global lake drilling holds potential for global change research

During the past decade, numerous international investigations of past global change have focused on particular time intervals, or “Time Streams,” suggested by the Past Global Changes (PAGES) Project of the International Geosphere‐Biosphere Programme (IGBP). Time Stream 1 encompasses the last 2000 years, and Time Stream 2 encompasses at least the last 250,000 years. Geographically many of...
Authors
Walter E. Dean, Joseph G. Rosenbaum, Brian J. Haskell, K. Kelts, Douglas Schurrenberger, Blas L. Valero Garces, Andrew S. Cohen, Owen Davis, D. Dinter, Dennis Nielson

Tertiary cooling and tectonic history of the White River uplift, Gore Range, and western Front Range, central Colorado: Evidence from fission-track and 39Ar/ 40Ar ages Tertiary cooling and tectonic history of the White River uplift, Gore Range, and western Front Range, central Colorado: Evidence from fission-track and 39Ar/ 40Ar ages

Apatite fission-track (AFT) data from Proterozoic and Paleozoic rocks in the mountains of north central Colorado (White River Uplift, Gore Range, and western Front Range) record significant cooling that began with uplift and erosion related to the Laramide Orogeny and continued through the Tertiary to Pliocene time. The mountains immediately flanking the Blue River half graben (Williams...
Authors
C. W. Naeser, Bruce Bryant, Michael J. Kunk, Karl S. Kellogg, R.A. Donelick, W. J. Perry
Was this page helpful?