Large-scale hydrothermal fluid discharges in the Norris-Mammoth corridor, Yellowstone National Park, USA

• Published in: Journal of geochemical exploration 2000-06, Vol.69-70 (1-3), p.201-205
• Main Authors: KHARAKA, Y. K, SOREY, M. L, THORDSEN, J. J
• Format: Article
• Language: English
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; Freshwater; Hydrogeology; Hydrology. Hydrogeology
• ISSN: 0375-6742; 1879-1689
• DOI: 10.1016/S0375-6742(00)00025-X

Norris-Mammoth corridor is a complex subsidence structure that extends similar to 40 km northward from the 0.6 Ma Yellowstone caldera, and contains many hydrothermal features with high fluid discharges totaling similar to 1000 l/s. About 150-250 l/s of hydrothermal water, which attains boiling temperature at surface and 360 degree C at depth, discharge from the Norris Geyser Basin, adjacent to the caldera. The highest thermal water and gas discharges in the corridor are from Mammoth Hot Springs, where 500-600 l/s thermal water with surface temperatures of up to 73 degree C and calculated subsurface temperatures of similar to 100 degree C issue from similar to 100 hot springs scattered over a score of step-like travertine terraces that range in age from similar to 0.4 Ma to recent. All the thermal water is meteoric, likely recharged in the Gallatin Range at 2.5-3.0 km elevations. The isotopic and chemical compositions of thermal waters and solutes can be interpreted to indicate a common magmatic source for heat and volatile solutes located near Norris. However, the chemical and isotopic compositions of gases, especially the super(3)He/ super(4)He ratios, provide strong evidence for a separate magmatic source for the Mammoth system.