A karst hydrochemical study of the Marble Mountain of northwestern California

Abstract

The Marble Mountains Karst, in the Klamath Mountains province of extreme northern California, is characterized by subsurface drainage, over-deepened cirques, and unique cave to surface relationships. This thesis is an attempt to understand the distinct hydrochemical processes occurring within this alpine karst watershed.

The hydrochemical system is fed by three source areas: bare karst (exhumed by past glaciations), soil-mantled karst under predominantly coniferous vegetation, and allogenic streams draining alpine lakes. Underground flows are traced to one major resurgence.

The differing soils and associated vegetation types affect the water chemistry draining this area. Biogenic activity in the soil results in higher CO2. The increased availability of CO2 enhances carbonic acid production and accelerates solutional weathering of the marble, especially within the soil-mantled karst.