Reanalysis of Selected Archived NURE-HSSR Sediment and Soil Samples from Arizona, California, Idaho, Montana, Nevada, New Mexico, and Utah
Beginning in November of 2015, a project was undertaken to reanalyze approximately 60,000 archived sample splits collected as part of the National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) project from selected areas in Arizona, California, Idaho, Montana, Nevada, New Mexico, and Utah. A small amount (approximately 0.25 g) of sieved -75 micron sample material was retrieved from the USGS National Geochemical Sample Archive for geochemical analysis. These samples were analyzed for 51 elements under a Technical Assistance Agreement with a third party by ALS Global laboratories using their ultra-trace four-acid-digestion dual-mode ICPMS (ALS ME-MS61L) method (Ag, Al,...
Whole rock, soil, sediment, x-ray diffraction, and electron microprobe analyses of samples from the Orange Hill-Bond Creek area, Nabesna Quadrangle, Alaska
This data release includes geochemical, x-ray diffraction mineralogical, and electron probe microanalysis (EPMA) data on rocks, soils, and sediments collected near the Orange Hill and Bond Creek porphyry copper deposits, Nabesna quadrangle, Alaska. Geochemical analyses were completed by a laboratory under contract with the U.S. Geological Survey (USGS). Electron microprobe and x-ray diffraction mineralogical analyses were completed by personnel of the Central Region Minerals Program in Denver, Colorado. The samples were collected and analyzed during 2014 to 2016, selected to help characterize the distribution and composition of mineralized and unmineralized geologic materials in this remote part of the eastern Alaska...
FY2014This project proposes to test the hypothesis that soil fungistasis (suppression of fungal pathogens by soil microbes in carbohydrate-limited soil) and its alleviation through natural carbohydrate augmentation (e.g., cheatgrass litter, leakage from cheatgrass roots) are the principal processes mediating patterns of cheatgrass die-off and recovery in die-off-prone areas.The project team will use laboratory, greenhouse, and field manipulative experiments to examine the effect of soil carbohydrates on cheatgrass disease incidence.
Using Soil Climate and Geospatial Environmental Characteristics to Determine Plant Community Resilience to Fire and Fire Surrogate Treatments
FY2014Avoiding cheatgrass dominance following tree-reduction treatments on woodland-encroached sagebrush communities is a priority for managers in the Great Basin. Perennial herbaceous and weedy annual cover have been related to site resilience after treatment and associated with soil climate regimes and site physical characteristics. Additional investigation of site characteristics associated with vegetation response will allow us to better decide which sites to treat and whether seeding is needed or not in conjunction with tree reduction treatments. Site-level planning also requires an understanding of how climate change may influence vegetation response to treatments.We propose to associate site-measured soil...