Brophy Occurrence Models

From Open Energy Information

Brophy Occurrence Models:
Paul Brophy has classified geothermal areas based on a variety of properties such as tectonic setting, controlling structures, and fluid properties.
Other definitions:Wikipedia Reegle

Type Examples Topography Climate Depth to Resource (m) Surface Manifestations Permeability
Type A: Magma-heated, Dry Steam Resource The Geysers Rugged to mountainous Variable Usually deep (2500-4000) Restricted Low to moderate fracture permeability
Type B: Andesitic Volcanic Resource Philippines, Indonesia, Central and South America Usually mountainous Variable - usually high precipitation Deep to moderate Restricted, depending on depth and shallow ground water Low to moderate fracture permeability - often high
Type C: Caldera Resource Medicine Lake, Valles Caldera, Los Humeros, Yellowstone Ring fractures; often rugged with gentle floor topography Variable Moderate to shallow (<2500) Common Low fracture permeability - often thin tuff units
Type D: Sedimentary-hosted, Volcanic-related Resource Imperial Valley Usually low topography Arid; low precipitation Intermediate (2000-3500) Very restricted Variable
Type E: Extensional Tectonic, Fault-Controlled Resource Great Basin Rugged on upthrow; low on valley floor Usually dry with low precipitation Usually deep (2500-3500) Usually restricted to fault traces Dominantly fault-controlled
Type F: Oceanic-ridge, Basaltic Resource Hawai'i, Iceland Rugged to flat Islands - high precipitation Shallow (1000-2000) Common High horizontal permeability, variable vertical permeability

These values are part of Category:Brophy Occurrence Models[1], and are used for Property:BrophyModel.[2]


  1. Paul Brophy. 2007. A Brief Classification of Geothermal Systems. Sparks, Nevada. GRC Annual Meeting. Geophysical Techniques in Geothermal Exploration Workshop; nap.
  2. Colin F. Williams, Marshall J. Reed and Arlene F. Anderson. 2011. Updating the Classification of Geothermal Resources - Presentation. In: Thirty-Sixth Workshop on Geothermal Reservoir Engineering; 2011/02/02; Stanford, California. Stanford, California: Stanford University; p. 23