Major-oxide and trace-element geochemical data from rocks collected in the Tok River area, Tanacross A-5 and A-6 quadrangles, Alaska in 2016

Geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) and University of Alaska carried out a two-part geologic mapping and geochemical sampling project in the Tok River area of the Tanacross A-5 and A-6 quadrangles (June 12-26 and July 8-26). The Tok River area is adjacent to the Delta mineral belt volcanogenic massive-sulfide (VMS) district, the Peak gold-silver-copper skarn, and the structurally controlled gold and antimony mineralization in the Stibnite Creek and White Gold areas. The Tok River project area includes the Noah (also called Hona) prospect, an intrusion-related copper prospect. The combination of insufficient detailed geologic mapping, historical and current industry interest in the adjacent mineralized areas, and the recently published geophysical data prompted the DGGS Mineral Resources section to work in this area. Highlights of this DGGS Tok River geochemical report include identification, sampling, and characterization of prospects without previously available public data, including the Eagle, Dall, Parton, and Jacqueline prospects. This dataset has 22 samples with gold in excess of 0.5 ppm in several different locations, including a sample with 9.78 ppm Au (16ET254, Shalovsky vein), a sample with 6.25 ppm Au from nearby Hona porphyry (16ET312), a sample containing 1.22 ppm Au from a vein within schist south of Dry Tok Creek (16KS255), and a sample with 1.315 ppm Au from drill hole WG-11-05 (16RN165B, Eagle trend). Major- and trace-element geochemical analyses were obtained for the metamorphic rocks to distinguish between igneous and sedimentary protoliths and for igneous rocks to characterize and differentiate Mesozoic and Cenozoic rocks in the area.