Some Aspects of Geochemical Exploration in Hawaii

Abstract

The high permeability of the basaltic lavas and the oceanic environment of Hawaii complicate geothermal exploration, and the formation of reservoirs requires the existence of impermeable structures, such as dike systems. These conditions also preclude the widespread formation of features such as hot springs, which are a major source of geochemical information. Although a large number of groundwater wells exist, they do not penetrate deep thermal groundwaters, limiting quantitative interpretation of their chemistry. Prospective areas have consequently been selected for more detailed studies on the basis of geology, qualitative groundwater chemistry ratio of concentration) and groundwater temperatures. A site specific geochemical approach has consequently been to utilize techniques dependent gas, such as ground radon (Rn) and the mercury (Hg) content and of soils. Surveys in three different areas are presented; two in rift zones and one in an extinct caldera.