English

Abstract

The lower Neosho River watershed has been negatively affected by intensive Pb and Zn mining that took place from the late 1800's through the mid- 1900's. The nearby region is recognized with several of the U.S. Environmental Protection Agency's Superfund Sites. The Tar Creek Superfund Site in Oklahoma is contaminated with ecotoxic metals such as lead, zinc, cadmium, and iron. In addition, millions of tonnes of mine tailings have been left on the surface near the neighboring towns of Picher and Cardin. Tar Creek is the main drainage through the Oklahoma portion of the mining area and a major source of contamination leading into the Neosho River and subsequently Grand Lake O' the Cherokees. Completion of the Pensacola Dam forming Grand Lake is a cause of backwater flooding in the Neosho River basin, which could lead to sediment and dissolved metals transport into the surrounding riparian areas. Due to the increased frequency of upstream flood events since construction of Grand Lake, a floodplain area on the Neosho River upstream of Tar and Elm Creeks was investigated for possible transport of mining-related metals using sediment core sampling and analysis techniques. Metals analysis showed total metals concentrations to have strong correlations with elevation in the floodplain area. Other relationships regarding metals concentrations and distance from the riverine area and particle size were inconclusive. Further study should be employed to characterize the quantities of metals on the remaining downstream stretch of the Neosho River.