Quantitative geochemistry of rocks from the Adelaide Mining District, Humboldt County, Nevada

Cookro, T.M.

doi:10.3133/ofr93249

Cited by 1 publication

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mineralized rocks and ores. Analytical results for four dump samples and two tailings samples are similar to the much more extensive data of Cookro (1993) and the known mineralogy: values for Pb, Zn, and Ag are high, as are As and Sb. Skarn ores and waste rocks are rich in base metals, arsenic, and sulfide minerals in the deeper unoxidized zones.…”

Section: Mineral-environmental Conditionssupporting

confidence: 74%

“…The silver-gold deposits were mined from many underground workings, in and near the north-striking Adelaide fault, over a distance of about 4 mi. Geochemical results of Cookro (1993) for more than 40 elements show wide variation locally in the belt of silver-gold mines, suggesting multiple types of geochemical enrichment, including the unconventional variety rich in Be-Li. The district may be geochemically zoned, albeit complexly.…”

Section: Adelaide District (Gold Run)mentioning

confidence: 99%

“…On the negative side, this district has widespread mining and surface trenching and very little reclamation. Geochemical studies (Cookro, 1993) show that the ores and waste piles contain high levels of base metals and arsenic. On the positive side, there is very little surface water, many of the ores are oxidized, and carbonatebearing rocks and gangue are abundant.…”

Section: Mineral-environmental Conditionsmentioning

confidence: 99%

See 2 more Smart Citations

Hydrogeochemical studies of historical mining areas in the Humboldt River basin and adjacent areas, northern Nevada

Nash¹

2005

Scientific Investigations Report

View full text Add to dashboard Cite

Reconnaissance field studies were made at 50 historical mining districts in northern Nevada to determine the actual or potential contamination of surface or ground water by mine drainage water, mine-waste dumps, and mill tailings. The main focus of this report is on mining areas in the central Humboldt River Basin, from approximately Elko to Winnemucca, with coverage of adjacent or analogous mining areas. More than 650 new chemical analyses of mine water, mine waste and tailings, and leachates of those materials are described and interpreted to provide Federal land-management agencies and the public with concepts regarding sources of mining-related contamination and the extent of contamination. The new observations and geochemical data suggest that contamination is not nearly as common or widespread as postulated by some in the popular press. Out of the tens of thousands of small prospects, small mines, and some large mines on public lands, less than 1 SDMS DOCID# 1141048Hydrogeochemical Studies of Historical Mining Areas in the Humboldt River Basin and Adjacent Areas, Northern Nevada percent of the historical sites pose significant threats to water quality, human health, or wildlife habitat.Although there are tens of thousands of small prospects in northern Nevada, these small diggings generally release no more contamination than the same rocks prior to mining. Out of the hundreds of small-to mediumsized mines on public lands, only a few release acidic mine drainage or significant concentrations of metal contaminants. Large historical mines generally are on private property (patented mining claims) and were not sampled in this study, but only a small percentage are known to produce significant contamination. The approach in this investigation was to identify the largest accessible historical mine or mines in a district for observation and sampling and to seek the worst case of likely contamination. Field observations suggest that visible indicators of acidic mine drainage (such as red, iron-rich precipitates) are rare, and field measurements of pH and chemical analyses of several kinds of materials (dump rocks, tailings, surface water) indicate that only a few sites release acid or significant concentrations of metals. The most consistent observation at and near mining areas is neutral to weakly alkaline pH values (6.5 to 8.4) and water compositions attesting to significant amounts of carbonate derived from rocks, alluvium, and caliche-bearing soils. The alkalinity of surface water is sufficient to naturally mitigate local sources of acidic water by mixing; the neutralization processes induce reactions that greatly reduce the concentrations of most metals in the evolved water. There are, however, indications of elevated amounts of arsenic, molybdenum, and selenium that are mobile in weakly alkaline water. There is some risk for these elements to be cumulatively enriched in closed basins over many years, but the magnitude of that risk is beyond the scope of this investigation.Acidic mine water loaded with toxic m...

show abstract

Section: Mineral-environmental Conditionssupporting

confidence: 74%

Section: Adelaide District (Gold Run)mentioning

confidence: 99%

Section: Mineral-environmental Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Quantitative geochemistry of rocks from the Adelaide Mining District, Humboldt County, Nevada

Cited by 1 publication

References 0 publications

Hydrogeochemical studies of historical mining areas in the Humboldt River basin and adjacent areas, northern Nevada

Hydrogeochemical studies of historical mining areas in the Humboldt River basin and adjacent areas, northern Nevada

Contact Info

Product

Resources

About