Hydrothermal processes at Mount Rainier, Washington
Field studies and thermal-infrared mapping at Mount Rainier indicate areas of active hydrothermal alteration where excess surface heat flux is about 9 megawatts. Three representative settings include: (1) An extensive area (greater than 12,000 m/sup 2/) of heated ground and slightly acidic boiling-point fumaroles at 76-82/sup 0/C at East and West Craters on the volcano's summit; (2) A small area (less than 500 m/sup 2/) of heated ground and sub-boiling-point fumaroles at 55-60/sup 0/C on the upper flank at Disappointment Cleaver, and other probably similar areas at Willis Wall, Sunset Amphitheater, and the South Tahoma and Kautz headwalls; (3) Sulfate and carbon dioxide enriched thermal springs at 9-24/sup 0/C on the lower flank of the volcano in valley walls beside the Winthrop and Paradise Glaciers. In addition, chloride- and carbon dioxide-enriched thermal springs issue from thin sediments that overlie Tertiary rocks at, or somewhat beyond, the base of the volcanic edifice in valley bottoms of the Nisqually and Ohanapecosh Rivers where maximum spring temperatures are 19-25/sup 0/C, respectively, and where extensive travertine deposits have developed. The heat flow, distribution of thermal activity, and nature of alteration products indicate that a narrow, central hydrothermal system exists within Mount Rainier forming steam-heated snowmelt at the summit craters and localized leakage of steam-heated fluids within 2 kilometers of the summit. The lateral extent of the hydrothermal system is limited in that only sparse, neutral sulfate-enriched thermal water issues from the lower flank of the cone. Simulations of geochemical mass transfer suggest that the thermal springs may be derived from an acid sulfate-chloride parent fluid which has been neutralized by reaction with andesite and highly diluted with shallow ground water.
- Research Organization:
- Washington Univ., Seattle (USA)
- OSTI ID:
- 5836056
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Geochemical studies of rocks, water, and gases at Mt. Hood, Oregon
Alaska Open-file Report 144 Assessment of Thermal Springs Sites Aleutian Arc, Atka Island to Becherof Lake -- Preliminary Results and Evaluation
Related Subjects
GEOTHERMAL FIELDS
MAPPING
MOUNTAINS
HYDROTHERMAL ALTERATION
HYDROTHERMAL SYSTEMS
INFRARED SURVEYS
WASHINGTON
MATHEMATICAL MODELS
ENERGY SYSTEMS
FEDERAL REGION X
GEOPHYSICAL SURVEYS
GEOTHERMAL SYSTEMS
NORTH AMERICA
SURVEYS
USA
150201* - Geology & Hydrology of Geothermal Systems- USA- (-1989)