| Abstract |
In March 1986, a research borehole, called the "State 2-14", reached a depth of 3.22 km in the Salton Sea Geothermal System (SSGS), on the delta of the Colorado River, in Southern California (Figure 1). This was part of the Salton Sea Scientific Drilling Project (SSSDP), the first major (Le., multi-million U. S. dollar) research drilling project in the Continental Scientific Drilling Program of tne U. S. A. The principal goals of the SSSDP were to investigate the physical and chemical processes going on in a high-temperature, high-salinity, hydrothermal system. The borehole encountered temperatures of up to 355°C and p'roduced metalrich, alkali chloride brines containing 25 weight per cent of total dissolved solids. The rocks penetrated exhibit a progressive transition from unconsolidated lacustrine and deltaic sediments to hornfelses, with lower amphibolite facies mineralogy, accompanied by pervasive copper, lead, &inc, and iron ore mineral. The SSSDP included an intensive program of rock and fluid sampling, flow testing, and downhole logging and scientific measurement (Elders and Sass, 1988). The purpose of this paper is to -describe briefly the background of the project and the drilling and testing of the borehole, and to summari&e some of the important scientific results. |