Soil Sampling At Salt Wells Area (Henkle, Et Al., 2005)
Exploration Activity: Soil Sampling At Salt Wells Area (Henkle, Et Al., 2005)
|Exploration Activity Details|
|Location||Salt Wells Area|
|Exploration Technique||Soil Sampling|
|Activity Date||- 2005|
Adsorbed mercury soil geochemical surveys and radiometric geophysical surveys were carried out in conjunction with geologic mapping to test the application of these ground-based techniques to geothermal exploration at three prospects in Nevada by Henkle Jr. et al. in 2005. Mercury soil vapor surveys were not widely used in geothermal exploration in the western US at the time, although the association of mercury vapors with geothermal fluids, hot springs, and/or soils has been recognized at the Steamboat Springs, NV, Roosevelt Hot Springs, UT, Dixie Valley, NV, Noya, Japan, and Moana, NV geothermal areas.
Soil sampling and geophysical surveys were conducted at 26 stations along an approximately 1981-m-long line oriented perpendicular to known major structures at Salt Wells. The exact geologic context of the traverse is difficult to discern, as the mapped fault is informally referred to as the “Pony Express Fault” in the text, and no plan map showing the exact location of the sampling line is provided. Sample station spacing along the line was 76.2 m. The same Gas’m technique used to measure desorbed mercury vapors in soils from known fault traces at the Moana Geothermal Area was utilized for the soil geochemical work in this study. The technique measures adsorbed mercury deposited on the silt- and clay-sized fractions of soils as mercury vapors sourced from buried active geothermal systems migrate upward from depth. Approximately 1 kg of soil was sampled from a depth of 30 to 45 cm at each sample station. Mercury analyses of the soil samples were conducted at the Minerals Exploration and Environmental Geochemistry laboratory in Reno, NV. A portion of the minus 325 mesh fraction of each sample was desorbed in a closed container at 50°C for 230 hours and at 100°C for another 70 hours. The desorbed mercury was then measured using a Tekran AFS mercury detector.
- William R. Henkle Jr., Wayne C. Gundersen, Thomas D. Gundersen (2005) Mercury Geochemical, Groundwater Geochemical, And Radiometric Geophysical Signatures At Three Geothermal Prospects In Northern Nevada