Publications
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Developing a bubble number-density paleoclimatic indicator for glacier ice
Past accumulation rate can be estimated from the measured number-density of bubbles in an ice core and the reconstructed paleotemperature, using a new technique. Density increase and grain growth in polar firn are both controlled by temperature and accumulation rate, and the integrated effects are recorded in the number-density of bubbles as the firn changes to ice. An empirical model of these pro
Authors
M. K. Spencer, R. B. Alley, J. J. Fitzpatrick
Age model for a continuous, ca 250-ka Quaternary lacustrine record from Bear Lake, Utah-Idaho
The Quaternary sediments sampled by continuous 120-m-long drill cores from Bear Lake (Utah-Idaho) comprise one of the longest lacustrine sequences recovered from an extant lake. The cores serve as a good case study for the construction of an age model for sequences that extend beyond the range of radiocarbon dating. From a variety of potential age indicators, we selected a combination of radiocarb
Authors
Steven M. Colman, D. S. Kaufman, Jordon Bright, C. Heil, J.W. King, W.E. Dean, J. G. Rosenbaum, R. M. Forester, J. L. Bischoff, Marie Perkins, J. P. McGeehin
Acoustic stratigraphy of Bear Lake, Utah-Idaho: late Quaternary sedimentation patterns in a simple half-graben
A 277-km network of high-resolution seismic-reflection profiles, supplemented with a sidescan-sonar mosaic of the lake floor, was collected in Bear Lake, Utah–Idaho, in order to explore the sedimentary framework of the lake's paleoclimate record. The acoustic stratigraphy is tied to a 120 m deep, continuously cored drill hole in the lake. Based on the age model for the drill core, the oldest conti
Authors
Steven M. Colman
Ice sheets and sea level: response
No abstract available.
Authors
Jonathan T. Overpeck, Bette L. Otto-Bliesner, Gifford H. Miller, Richard B. Alley, Daniel R. Muhs, Shawn J. Marshall
Atmospheric dust in modern soil on aeolian sandstone, Colorado Plateau (USA): Variation with landscape position and contribution to potential plant nutrients
Rock-derived nutrients in soils originate from both local bedrock and atmospheric dust, including dust from far-distant sources. Distinction between fine particles derived from local bedrock and from dust provides better understanding of the landscape-scale distribution and abundance of soil nutrients. Sandy surficial deposits over dominantly sandstone substrates, covering vast upland areas of the
Authors
Richard L. Reynolds, J. Neff, Marith C. Reheis, Paul J. Lamothe
Soil respiration in the cold desert environment of the Colorado Plateau (USA): Abiotic regulators and thresholds
Decomposition is central to understanding ecosystem carbon exchange and nutrient-release processes. Unlike mesic ecosystems, which have been extensively studied, xeric landscapes have received little attention; as a result, abiotic soil-respiration regulatory processes are poorly understood in xeric environments. To provide a more complete and quantitative understanding about how abiotic factors i
Authors
D. P. Fernandez, J. C. Neff, Jayne Belnap, Richard L. Reynolds
Controls of bedrock geochemistry on soil and plant nutrients in Southeastern Utah
The cold deserts of the Colorado Plateau contain numerous geologically and geochemically distinct sedimentary bedrock types. In the area near Canyonlands National Park in Southeastern Utah, geochemical variation in geologic substrates is related to the depositional environment with higher concentrations of Fe, Al, P, K, and Mg in sediments deposited in alluvial or marine environments and lower con
Authors
J. C. Neff, Richard L. Reynolds, R.L. Sanford, D. Fernandez, Paul J. Lamothe
Understanding the spatial heterogeneity of global environmental change in mountain regions
One of the challenges for global environmental change research is to understand how future climate changes will be expressed in mountain regions. The physiographic complexity of mountains creates environments that can be highly variable over relatively short distances. This spatial heterogeneity reflects a hierarchy of environmental controls. At regional scales, insolation and atmospheric circulat
Authors
Sarah Shafer, Patrick J. Bartlein, Cathy Whitlock
Preliminary geologic map of southernmost Texas, United States, and parts of Tamaulipas and Nuevo Leon, Mexico: Environmental health investigations in the United States-Mexico border region
No abstract available.
Authors
William R. Page, D. Paco VanSistine, Kenzie J. Turner
Stratigraphy and structural history of the eastern edge of the Helena salient, Montana
No abstract available.
Authors
Mitchell W. Reynolds
Structural termination of the Montana disturbed belt and its interaction with major structures of the continental autochthon
No abstract available.
Authors
Mitchell W. Reynolds
Laccoliths of the southwest part of the Little Belt Mountains; their relation to ancestral structures of the Central Montana Uplift
No abstract available.
Authors
Mitchell W. Reynolds