Definition: Field Sampling
Systematic field sampling is critical for reliable characterize a geothermal resource. Some of the physical and chemical properties of rock samples can be estimated by visual inspection, but accurate determination of these properties requires detailed laboratory analysis. Surface or subsurface fluid sampling is also routinely performed to characterize the chemical, thermal, or hydrological properties of a hydrothermal system. Combinations of these sampling techniques have traditionally been used to obtain important information used to determine whether or not a viable power generation or heat utilization facility can be developed at a prospect. Soil sampling is a less commonly used method for exploration of geothermal resources that lack obvious surface manifestations. Soils that are above or adjacent to a “hidden” hydrothermal system will have a unique chemistry that can be indicative of a hydrothermal system at depth or of zones of relatively high subsurface permeability.