Ward, A.J., Alpers, C.N., Campbell, K.M., Kane, T.J., Roth, D.A., Plowman, T.I., Antweiler, R.C., Monohan, C., Howle, J.F., Curtis, J.A., and Orlando, J., 2019, Geochemical, mineralogical, and grain-size data for in-situ solid materials and suspended sediment at Malakoff Diggins State Historic Park, Nevada County, California: U.S. Geological Survey data release, https://doi.org/10.5066/P95RLMEI.
Runoff from within the mine pit at Malakoff Diggins State Historic Park discharges through Hiller Tunnel, a man-made, 557-foot-long drainage tunnel, into Diggins Creek for a short distance, and then into Humbug Creek. A tributary to the South Yuba River, Humbug Creek is currently on the State of California’s 303(d) list for impaired waters because of pH, elevated sedimentation/siltation, chromium, copper, iron, mercury, and zinc. The Malakoff Diggins mine pit is known to be a primary source of contamination for suspended solids and heavy metals including copper, mercury, and zinc to the Humbug Creek watershed. Chemical and physical characterization of the in-situ solid samples and suspended-sediment samples collected for this project may reveal key indicators, or fingerprints, which will allow for the identification of specific stratigraphic units, or geographic areas within the mine pit, that are delivering high amounts of sediment and heavy metals to Humbug Creek, and may be used to inform land-management efforts in Malakoff Diggins State Historic Park.