Geothermal phenomena in the vicinity of Klamath Falls, Oregon, include hot springs, steam and water wells with temperatures exceeding 100 deg C, and several hundred warmwater wells with temperatures ranging from 20 deg C to 35 deg C. Hot water is confined to three relatively restricted areas located near major fault and fracture zones of the Basin and Range type. The water is produced mostly from Tertiary basalt and volcanic sediments. The hot waters contain less than 1000 mg/liter of dissolved solids and have compositions dominated by sodium and sulfate. Silica concentrations are less than 100 mg/liter, and the minimum estimated reservoir temperature based on silica content is 130 deg C. Cation ratios suggest that actual reservoir temperatures are not much greater than the estimated minimum. The temperature regime in the upper 500-600 meters of rock is dominated by convective transport, and gradients exceed 150 deg C per kilometer at places. Heat flow in the area, however, may be no more than 1.5 - 2 heat-flow units. In the absence of evidence for a shallow intrusive body of hot rock, the geothermal phenomena are attributed to deep circulation of meteoric water. The reservoir may be one of the largest hot-water geothermal systems in the United States. (Woodard-USGS)
Additional Publication Details
USGS Numbered Series
Hydrologic reconnaissance of the geothermal area near Klamath Falls, Oregon
Water-Resources Investigations Report
Water Resources Division, U.S. Geological Survey,
149 p. in various pagings :ill., maps (some fold. in pocket) ;30 cm.