| Title | Subsurface Geology and Geothermal Prospects in the Nampa-Caldwell Area of the Western Snake River Plain, Idaho |
|---|---|
| Authors | Wood, Spencer H.; Mitchell, John C.; Anderson, John |
| Year | 1980 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Exploration; USA; Idaho; Nampa-Caldwell; Western Snake River Plain; Geological Surveys; Basalt; Mapping; Geophysical Surveys; Temperature; Electrical Conductivity; Reflection |
| Abstract | Subsurface geological and geophysical data show a 2100-m thick sequence of interbedded basalt and sediment lie beneath the Idaho Group sediments in the Nampa - Caldwell area of the western Snake River Plain. Numerous faults in the subsurface define a central horst that divides the subsurface into separate basins. Overlying the basalt section are widespread sandstone aquifers that can be expected to yield good flows of moderately warm waters (30-55°C) from depths of 300 to 650 m. Normal faulting occurs throughout most of the stratigraphic section, but fault offsets diminish upwards. Deep wells drilled to encounter fracture zones associated with faulting may produce high temperature waters, but these prospects are considerably more speculative than the sandstone aquifers. |