Publications

No abstract available.

The interactions between playa hydrology and playa-surface sediments are important factors that control the type and amount of dust emitted from playas as a result of wind erosion. The production of evaporite minerals during evaporative loss of near-surface ground water results in both the creation and maintenance of several centimeters or more of loose sediment on and near the surfaces...

There is little geochonological data on sedimentation in dambos (seasonally saturated, channel-less valley floors) found throughout Central and Southern Africa. Radiocarbon dating is problematic for dambos due to (i) oxidation of organic materials during dry seasons; and (ii) the potential for contemporary biological contamination of near-surface sediments. However, for luminescence...

Controversy exists over whether alluvial-fan sedimentation along tectonically active mountain fronts is driven by climatic changes or tectonics. Knowing the age of sedimentation is the key to understanding the relationship between sedimentation and its cause. Alluvial-fan deposits in Death Valley and throughout the arid southwestern United States have long been the subjects of study, but...

The chronology of the Holocene and late Pleistocene deposits of the northeastern Mojave Desert have been largely obtained using radiocarbon ages. Our study refines and extends this framework using optically stimulated luminescence (OSL) to date deposits from Valjean Valley, Silurian Lake Playa, Red Pass, and California Valley. Of particular interest are eolian fine silts incorporated in...

The headwaters of the Bear River drainage were occupied during the Last Glacial Maximum (LGM) by outlet glaciers of the Western Uinta Ice Field, an extensive ice mass (???685 km2) that covered the western slope of the Uinta Mountains. A well-preserved sequence of latero-frontal moraines in the drainage indicates that outlet glaciers advanced beyond the mountain front and coalesced on the...

No abstract available.

This map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying those parts of the Santa Barbara coastal plain and adjacent southern flank of the Santa Ynez Mountains within the Goleta 7 ?? quadrangle at a compilation scale of 1:24,000 (one inch on the map = 2,000 feet on the ground) and with a horizontal positional accuracy of at least 20...

Climate is the primary factor controlling the continental-scale distribution of plant species, although the relations between climatic parameters and species' ranges are only now beginning to be quantified. This volume examines the relations between climate and the distributions of (1) Kuchler's 'potential natural vegetation' categories for the 48 contiguous States of the United States...

Since the start of the active 2000 summer fire season, the U. S. Geological Survey (USGS) Rocky Mountain Geographic Science Center (RMGSC) has been actively engaged in providing crucial and timely support to Federal, State, and local natural hazards monitoring, analysis, response, and recovery activities. As part of this support, RMGSC has developed the Rapid Data Delivery System (RDDS)...

Results from luminescence dating on 13 samples from the Albuquerque area show that major-drainage fluvial deposits represent significant periods of aggradation that formed paired, correlatable terraces on the east and west margins of the Rio Grande valley . The youngest terrace fills (Primero Alto) formed during late Pleistocene as a result of streamflow variations with climate cooling...

Bear River, the largest river in the Great Basin, had some of its flow diverted into Bear Lake through a series of canals constructed between 1911 and 1918, turning Bear Lake into a reservoir. The prediversion lake had an unusually high Mg2+ : Ca2+ ratio (38 by weight), which resulted in precipitation of CaCO3 as aragonite. The amount and mineralogy of the carbonate did not change...