Geochemical data for stream water samples from streams around the Pogo Deposit and Black Mountain Au occurrences, Big Delta quadrangle, Alaska, 2021

This data release is the result of a hydrogeochemical sampling campaign during summer 2021 to investigate whether high resolution geochemical analysis of waters for element chemistry can be used as an exploration tool for identifying gold-rich occurrences in parts of the Big Delta B-1 and B-2 quadrangles, within the Yukon-Tanana Upland region, Alaska. Historical USGS conventional stream sediment geochemical data yielded variable indications of geochemical anomalies in conventional stream sediment geochemistry results, probably related to relative exposure of mineralized rock. Previous studies of waters in the Pogo area (western part of current study) utilized conventional analytical methods not capable of measuring low concentrations of many elements (Wang et al., 2005).

In the current study, water samples were collected from 36 stream sample sites, with a focus on streams around Black Mountain to the east and the Pogo Au deposit area to the west. Both areas have known gold-rich mineral occurrences. In the eastern Black Mountain area, this included the Gray Lead, Blue Lead, and Michigan prospects, among others (U.S. Geological Survey, 1996). Sampling in the Pogo area was restricted to streams outside Leise Creek area due to anthropogenic disturbance as part of mining. Stream water samples were collected in 2021 and analyzed for cation and anion concentrations using high-resolution ICP-MS for cations and ion chromatography (IC) for anions.

Reference 
Wang, B., Wanty, R.B., and Vohden, J., 2005, Geochemistry of Surface-Waters in Mineralized and Non-Mineralized areas of the Yukon-Tanana Uplands, in Walton, R., ed., Impacts of Global Climate Change: World Water and Environmental Resources Congress, p. 1-8, https://doi.org/10.1061/40792(173)245.