Dr. Rod Parnell
Professor of Geology and Environmental Science
Research Site Location: White Mountains
The White Mountains are located north of several major copper mines in south-central and southeastern Arizona. The smeltering process by which the copper is extracted from the ore at these mines can produce airborne pollutants that can harm the environment. Dr. Mark Williamson and Dr. Rod Parnell of Northern Arizona University undertook a study to assess whether or not airborne heavy metals such as copper or zinc from these mines have been polluting high-elevation lakes in the White Mountain region. The White Mountains may be especially sensitive to acid rain and trace metal deposition resulting from this mining activity because much of the bedrock in the area is volcanic, which, unlike limestone, does not neutralize acid well. The researchers focused their study on Pacheta Lake.
To understand the geochemistry and assess the concentrations of potentially hazardous heavy metals in Pacheta Lake, the researchers first took sediment cores from the bottom of the lake. These cores are taken by floating out onto the lake in a boat and plugging a coring device down into the mud below. This core was later analyzed in a lab to determine the composition of the sediments and the water within the pores of the sediments and how these could be affecting the water quality of the lake.
Results from the study indicated that Pacheta Lake had not been contaminated above "baseline" levels by airborne pollutants produced by the large copper mines to the south. However, the study did provide valuable data to monitor possible degradation in the future.