HYDROGEOCHEMICAL VARIABILITY AMONG PIT LAKES IN NEVADA AND CALIFORNIA

The success of predictive models in forecasting metal mine pit lake chemistry through time depends on many factors, one being an accurate knowledge of the range of hydrologic and geochemical conditions in existing pit lakes. To this end, we have assembled a digital dataset for 48 pit lakes: 46 in NV and 2 in CA. Data sources were the hardcopy records of the Nevada Bureau of Mining Regulation and Reclamation, Carson City, NV, and of the California Dept. Water Resources, Sacramento, CA.

The dataset was created in Microsoft Access and the data fields include (when available): (1) chemistry of lake-, ground-, and surface water; (2) lake water and ground water elevation; (3) dates when the lakes began to fill; (4) pit size, location, and elevation; (5) climate data including rain and snowfall records, average and range of annual air temperatures; (6) deposit type of the mined resource; (7) chemistry and mineralogy of the ore and associated lithologies; (8) rock leachate chemistry; and (9) the source of the data and analytical methods.

This dataset will be used to determine the range and variability (in space and time) in concentrations of major and minor elements and pH. It will allow for the correlation of chemical variability to hydrologic conditions and deposit type and ore and host rock mineralogy. The dataset will also be used to test predictive models of pit lake chemistry.