Publications
Filter Total Items: 1492
Late Quaternary eolian records of the Americas and their paleoclimatic significance Late Quaternary eolian records of the Americas and their paleoclimatic significance
No abstract available.
Authors
Daniel R. Muhs, Marcelo Zarate
Aeolian dust in Colorado Plateau soils: Nutrient inputs and recent change in source Aeolian dust in Colorado Plateau soils: Nutrient inputs and recent change in source
Aeolian dust (windblown silt and clay) is an important component in arid-land ecosystems because it may contribute to soil formation and furnish essential nutrients. Few geologic surfaces, however, have been characterized with respect to dust-accumulation history and resultant nutrient enrichment. We have developed a combination of methods to identify the presence of aeolian dust in arid...
Authors
Richard L. Reynolds, Jayne Belnap, Paul Lamothe, Fred Luiszer
Biodiversity losses: The downward spiral Biodiversity losses: The downward spiral
The dramatic decline of whitebark pine (Pinus albicaulis) populations in the northwestern United States and southwestern Canada from the combined effects of fire exclusion, mountain pine beetles (Dendroctonus ponderosae), and white pine blister rust (Cronartium ribicola), and the projected decline of whitebark pine populations rangewide (Chapters 10 and 11) do not simply add up to local
Authors
Diana F. Tomback, Katherine C. Kendall
U-Th-Pb dating of hydrothermal minerals from Carlin-type gold deposits, Nevada- Results and evaluation U-Th-Pb dating of hydrothermal minerals from Carlin-type gold deposits, Nevada- Results and evaluation
No abstract available.
Authors
A. H. Hofstra, Wayne R. Premo, Poul Emsbo, J. S. Cline, John N. Aleinikoff
Age and Pb-Sr-Nd isotopic systematics of plutonic rocks from the Green Mountain magmatic arc, southeastern Wyoming: Isotopic characterization of a Paleoproterozoic island arc system Age and Pb-Sr-Nd isotopic systematics of plutonic rocks from the Green Mountain magmatic arc, southeastern Wyoming: Isotopic characterization of a Paleoproterozoic island arc system
Three new U-Pb zircon ages and the Pb-Sr-Nd isotopic systematics of 24 whole-rock samples from mainly plutonic rocks of the Sierra Madre and Medicine Bow Mountains near the Colorado-Wyoming border help establish the Green Mountain magmatic arc as a Paleoproterozoic, variably eroded, island arc terrane. The Green Mountain magmatic arc, a terrane composed of variably metamorphosed volcanic...
Authors
Wayne R. Premo, R. R. Loucks
Superposed fold-thrust events at the Nevada Test Site Superposed fold-thrust events at the Nevada Test Site
The Nevada Test Site (NTS), in southern Nye County, Nevada, straddles significant pre-Tertiary structural and stratigraphic boundaries. Detailed stratigraphy and biostratigraphy of the Upper Paleozoic section delineates the regional trust sheets and constrains their burial histories. The Paleozoic rocks record three phases of contractional deformation, overprinted by strike-slip faulting...
Authors
Patricia H. Cashman, J. C. Cole, James H. Trexler
SHRIMP U-Pb zircon ages for Big Creek gneiss, Wyoming and Boulder Creek batholith, Colorado: Implications for timing of Paleoproterozoic accretion of the northern Colorado province SHRIMP U-Pb zircon ages for Big Creek gneiss, Wyoming and Boulder Creek batholith, Colorado: Implications for timing of Paleoproterozoic accretion of the northern Colorado province
Sensitive, high-resolution, ion microprobe (SHRIMP) U-Pb zircon ages from a sample of the high-grade, hornblende-feldspathic Big Creek gneiss of the southeastern Sierra Madre, along with samples of a quartz monzonitic phase of the Boulder Creek batholith, help define timing of three major Paleoproterozoic thermo-tectonic events within the northern Colorado province at approximately 1810...
Authors
Wayne R. Premo, C. Mark Fanning
Hydrologic and geologic characteristics of the Yucca Mountain site relevant to the performance of a potential repository; Day 2, Beatty to Yucca Mountain; Stop 7B, Secondary minerals and paleohydrologic implications Hydrologic and geologic characteristics of the Yucca Mountain site relevant to the performance of a potential repository; Day 2, Beatty to Yucca Mountain; Stop 7B, Secondary minerals and paleohydrologic implications
No abstract available.
Authors
Leonid A. Neymark, James B. Paces, Zell E. Peterman, B. M. Marshall, Joseph F. Whelan
Paleoearthquake recurrence on the East Paradise fault zone, metropolitan Albuquerque, New Mexico Paleoearthquake recurrence on the East Paradise fault zone, metropolitan Albuquerque, New Mexico
A fortuitous exposure of the East Paradise fault zone near Arroyo de las Calabacillas has helped us determine a post-middle Pleistocene history for a long-forgotten Quaternary fault in the City of Albuquerque, New Mexico. Mapping of two exposures of the fault zone allowed us to measure a total vertical offset of 2.75 m across middle Pleistocene fluvial and eolian deposits and to estimate
Authors
Stephen F. Personius, Shannon Mahan
Biomes of western North America at 18,000, 6000 and 0 14C yr BP reconstructed from pollen and packrat midden data Biomes of western North America at 18,000, 6000 and 0 14C yr BP reconstructed from pollen and packrat midden data
A new compilation of pollen and packrat midden data from western North America provides a refined reconstruction of the composition and distribution of biomes in western North America for today and for 6000 and 18,000 radiocarbon years before present (14C yr BP). Modern biomes in western North America are adequately portrayed by pollen assemblages from lakes and bogs. Forest biomes in...
Authors
R.S. Thompson, K. H. Anderson
Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America; additional conifers, hardwoods, and monocots Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America; additional conifers, hardwoods, and monocots
This volume explores the continental-scale relations between climate and the geographic ranges of woody plant species in North America. A 25-km equal-area grid of modern climatic and bioclimatic parameters for North America was constructed from instrumental weather records. The geographic distributions of selected tree and shrub species were digitized, and the presence or absence of each...
Authors
Robert S. Thompson, Katherine H. Anderson, Patrick J. Bartlein, Sharon A. Smith