Geochemistry and isotope hydrogeology of the Mount Edziza – Mess Creek geothermal area
The Mount Edziza volcanic complex, a Recent volcano within British Columbia's northern Intermontane Belt, and the adjacent Mess Creek valley are investigated to evaluate the origin, geothermal history, and age of associated thermal waters. Samples of thermal and cold groundwaters, runoff, and glacier ice were collected for chemical and environmental isotope (18O/2H, 3H, , ) analysis.Mount Edziza thermal waters, discharging at 36 and 46 °C from extensive travertine formations at the base of the volcanic pile, originate as glacier meltwater on the summit of the complex. Their Na(Ca,Mg)–HCO3 chemistry is a product of alteration reactions with alkali basalts under a high CO2 partial pressure. Chemical and isotopic geothermometers suggest that subsurface temperatures are less than about 100 °C. Carbon-13 data show that the high carbon dioxide contents (close to 1 bar (100 kPa) pressure) likely originate through high-temperature decarbonation of marine carbonates at depth, and manifest a deep geothermal compone...