Hostrocks in the AW-45 area consist of a belt of Lower Jurassic northerly trending, reddish to maroon andesitic volcaniclastic and volcanic rocks (mainly tuffs) of the Betty Creek Formation and Lower Jurassic andesitic volcanic rocks of the Unuk River Formation, both Hazelton Group. Extensive and pervasive carbonate alteration is very common in the maroon pyroclastics and flows.
A sample was taken from a lens of chert 1 metre thick hosted in limestone with some extremely fine-grained disseminated pyrite and abundant limonite. The sample assayed 8.2 grams per tonne silver 0.12 per cent lead and 0.36 per cent zinc (Assessment Report 36401). A nearby brecciated limestone with vuggy chert was also observed and sampled. This was reported to form lenses several meters in size within andesite pyroclastics.
Refer to Ataman (104A 179) for related geological details and a more complete work history of the Surprise Creek Property.