Geologic descriptionThis prospect near VABM Tatalina consists of several tourmaline-bearing breccia bodies in an irregularly shaped body of quartz porphyry near the Tatalina Mountain syenite intrusion. The Tatalina Mountain syenite body just east of the prospect area has a 40K/40Ar biotite age of 61.3 Ma (Bundtzen and Laird, 1983). The tourmaline breccias crop out discontinuously over an area about 0.6 mile by 1.2 mile in size south of VABM Tatalina. Near the breccia, tourmaline has replaced some of the hornfels and the quartz syenite pluton as well as the quartz porphyry intrusion (D.B. Obolewicz, written communication, 1981; Bundtzen and Laird, 1983). Grab samples of stained tourmaline breccia have ocherous coatings without sulfides and contained up to 0.96 percent lead, 90.0 parts per million (ppm) silver, 240 ppm copper, 900 ppm zinc, 45 parts per billion (ppb) gold, more than 1,000 ppm arsenic, 200 ppm antimony, 760 ppb mercury, and 28 ppm tin (D.B. Obolewicz, written communication, 1981). Samples collected by McGimsey and others (1988) contained up to 10.0 ppm silver, 500 ppm lead, and 20 ppm tin. Two samples collected by Bundtzen and Laird (1983) contained 5.0 ppm silver and 1,000 ppm vanadium. In 2001, North Star Exploration, Inc., conducted a soil survey over the prospect and detected several elliptical-shaped anomalous areas. The soils contained up to 125 parts per billion (ppb) gold, 16.8 parts per million (ppm) silver, 1,039 ppm lead, 1,096 ppm zinc, 4.4 ppm cadmium, 1,308 ppm boron, 438 ppm arsenic, 54 ppm antimony, and 104 ppm bismuth (North Star Exploration, Inc., unpublished data, 2001). The elevated gold values in the soil were more sparsely distributed than the anomalous base metal and silver values. Bundtzen and Miller (1997) correlate this prospect with other silver-tin-polymetallic prospects in the Kuskokwim mineral belt. |
