Siliciclastic sedimentary rocks at McKinnon Creek, Indian River area, consist of interbedded sandstone, conglomerate, siltstone and coal, in order of decreasing abundance. The sediments are Lower Cretaceous (Albian) in age and were deposited in fluvial and deltaic environments. Strata are at least 500 m thick and subdivided into a lower lithic unit and an upper quartzose unit. Upper Cretaceous-Paleocene andesite dykes and sills intrude the sedimentary rocks.
Conglomerates of the upper quartzose unit contain up to 3.4 g/t gold. Historically, this deposit was regarded as a plaeoplacer. However, an epithermal origin is suggested by extensive quartz and clay cementation and authigenic pyrite and tourmaline in the conglomerates and by their close proximity to faulting and intrusions. The area should be reassessed for its economic potential.
