Geologic descriptionStill and others (1991) indicate that this occurrence is located in metabasalt along a north-northwest-striking lineament that is likely a splay off the fault that runs through Flat Bay. Brecciated sphalerite-bearing basalt boulders up to 1 foot by 2 foot in size contained up to 6.23 ppm gold, 13 ppm silver, 27% zinc, 2,600 ppm copper, 13 ppm tungsten, and 50 ppm arsenic. Iron-stained metabasalt rubble crop with chalcopyrite, pyrite, and malachite in a quartz knot contained 0.446 ppm gold, 220 ppm zinc, and 8,400 ppm copper. A stream sediment sample 0.8 miles north of this site and along the same lineament contained 0.024 ppm gold, 1.5 ppm silver, 3,000 ppm zinc, 1,150 ppm copper, and 590 ppm lead. Plafker, Hudson, and Silberling (1979) and Plafker and Hudson (1980) note that metabasalts on the Chilkat Peninsula are vesicular and/or amygdaloidal and that well-developed pillow textures are locally present. Based in part on fossil evidence that supports a Late Triassic (Karnian) age, they suggest that the metavolcanics and carbonates may correlate with similar rocks of the Wrangellia terrane. The age of the mineralization is not well established, but can be no older than the Late Triassic age of the host rocks. If the structure that localizes the mineralization is related to the nearby Chilkat Fault, then the age of the mineralization is probably Tertiary or younger as most movement on the Chilkat Fault has been post-Mesozoic (Lanphere, 1978). |
| Age of mineralization |
The age of this occurrence is not well established, but can be no older than the Late Triassic age of the host rocks (Plafker, Hudson and Silberling, 1979; Plafker and Hudson, 1980). If the structure that localize the mineralization is related to the Chatham Strait Fault, then the age of the mineralization is probably Tertiary or younger as most movement on the Chilkat Fault has been post-Mesozoic (Lanphere, 1978). |
