The Konocti Bay Fault Zone, Lake County, California: A Reevaluation

Abstract

The Konocti Bay Fault Zone (KBFZ), initially regarded by some as a promising liquid dominated hydrothermal system, has been a disappointment as a geothermal prospect. Five exploratory wells have been drilled in the vicinity of the KBFZ, but none of them are producing thermal fluids; in fact, three have been abandoned. This may be because of hydrothermal fluid discharges along the KBFZ are low. The Na-K-Ca and Na-Li geothermometers indicated that the waters discharging around Howard and Seigler Springs may have equilibrated at temperatures above 200°C. If boiling has occurred or is occurring, a chloride enthalpy diagram may be appropriate. Such a diagram fro the KBFZ shows that a water in excess of 250°C existed or may exist in the area. However, because currently measured temperatures nearly exceed 50°C an magnesium concentration in the water is high, very little deep high temperature water may be present; in other words, though the area appears to contain a high temperature fluid, there may not be much of it.