A chlorine-36 study of regional groundwater flow and vertical transport in southern Nevada.

Moran, Jean E.; Rose, Timothy P.

Chlorine-36 data for groundwater from the Death Valley regional flow system is interpreted in the context of existing conceptual models for regional groundwater flow in southern Nevada. Chlorine-36 end member compositions are defined for both recharge and chemically evolved groundwater components. The geochemical evolution of 36Cl is strongly controlled by water–rock interaction with Paleozoic carbonate rocks that comprise the regional aquifer system, resulting in chemically evolved groundwater that is characteristically low in 36Cl/Cl and high in Cl. Groundwater from alluvial and volcanic aquifers that overlie the regional carbonate aquifer are generally characterized by high 36Cl/Cl and low Cl signatures, and are chemically distinct from water in the regional carbonate aquifer. This difference provides a means of examining vertical transport and groundwater mixing processes. In combination with other geochemical and hydrogeologic data, the end members defined here provide constraints on aquifer residence times and mixing ratios.

NEVADA; HYDROGEOLOGY; VALLEYS; GROUNDWATER; GROUNDWATER monitoring; ROCKS

Environmental Geology, 2003, Vol 43, Issue 5, p592

0943-0105

Academic Journal

10.1007/s00254-002-0683-z