| Abstract |
Although the Cascade Range is an active volcanic chain with elevated heat flow, geothermal resources identified to date are modest. Estimates of the undiscovered accessible resource base of geothermal energy in the Cascade Range range widely, from a low of several hundred x 10(18) J to a high of over 15,000 x 10 (18) J. The higher estimates imply that undiscovered deep hydrothermal convection systems exist in the Cascade Range but are masked by overlying cold ground water in the permeable young volcanic rocks. The U.S. Geological Survey is analyzing the tectonic, volcanic, and hydrologic setting of the Cascade Range as a basis for a quantitative geothermal-resource assessment. Evaluation of the undiscovered accessible resource base, however, is critically dependent on deep exploratory drilling carried out by other agencies and industry. |