Page 70 - Geologic Investigations in the Lake Valley Area, Sierra County, New Mexico

Contents
Abstract ......................................................................................................................................... 65 Introduction ................................................................................................................................... 65 Background......................................................................................................................... 65 Lake Valley District—Location, Geology, Ore Deposits, and Mining History .......... 65 Acknowledgments ............................................................................................................. 68 Methods ........................................................................................................................................ 68 Field Methods ..................................................................................................................... 68 Study Site Identification and Sampling Strategy................................................. 68 Analysis ...................................................................................................................... 68 Water Leach Studies................................................................................................ 68 Statistical Techniques and Central and Expected Ranges of Occurrence.............. 68 Results ............................................................................................................................................ 69
Trace Elements of the Lake Valley District Mine Dumps and Water
Leach Studies ..................................................................................................................... 69 Discussion...................................................................................................................................... 70 Particle Size Effects; Correlations; Weathering ........................................................... 70 Acid Water Production Potential .................................................................................... 70 Geoenvironmentally Significant Trace Elements (GSTE) and GSTE Score.............. 71 GSTE Scores for Lake Valley Mine Dumps.................................................................... 72 Combining Other Factors with GSTE Score................................................................... 72 Summary and Conclusions.......................................................................................................... 74
Figures
1. Map showing location of Lake Valley mining district and neighboring
districts, southwestern New Mexico............................................................................... 66
2. Diagrams showing central ranges of concentrations of trace elements
of <2 mm material on mine dumps in Lake Valley.......................................................... 69
3–4. Spider diagrams combining geoenvironmentally significant trace element (GSTE) highest score, total S as a measure of acid generation potential, CO2 as a measure of carbonate to counteract acid generation and:
3. Concentrations of Pb, Sb, and Zn ............................................................................... 73
4. Solubilities of As, Cd, Pb, Sb, and the Cu:Mo ratio .................................................. 74
Tables
1. Trace element concentrations, means, ranges, and GSTE scores for
composited mine dump samples ...................................................................................... 67
Note: Combined references list begins on page 76.