Geologic description
Still (1988) indicates that, 'Mineralization is located in metabasalt sea cliffs up to 50 feet high that contain numerous narrow shear zones at various orientations. Some of the shears are silicified and contain copper or copper-zinc mineralization. Samples collected from these 0.2- to 1.4-foot-thick shear-controlled veins contain up to 2.54 ppm gold, 22.5 ppm silver, 6.9% copper, and 2.14% zinc.' Plafker, Hudson, and Silberling (1979) and Plafker and Hudson (1980) note that on the Chilkat Peninsula the same metabasalts 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 shearing and mineralization are both 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 the mineralization is not well established, but must be no older than the Late Triassic (Karnian) age of the metabasalts that host the deposit (Plafker, Hudson and Silberling, 1979; Plafker and Hudson, 1980). If the shearing and mineralization are both related to the nearby 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). |
