The Dexter zone showing area is largely underlain by volcaniclastic rocks of the Middle Jurassic Smithers Formation, Hazelton Group and by felsic (rhyolitic) volcanics of the Eocene Ootsa Lake Group. Quartz dioritic stocks, dikes and plugs of the Late Cretaceous Bulkley Plutonic Suite and Eocene felsitic intrusive rocks intrude the volcanics.

The Dexter Zone was documented in 2009. It is and alteration zone located 600 metres north of the Moraine zone but separated from it by weakly altered rhyolite clast-bearing polymictic lithic tuff and megacrystic andesite/dacite porphyry. A 20 metre wide zone of fine grained silica-pyrite alteration and quartz veining is hosted by Ootsa Lake Group polymictic lapilli tuff to tuff breccias. The tuff is strongly silicified by fine-grained silica containing finely disseminated pyrite and cut by vuggy quartz veins. Overall orientation and strike extent of the zone is not well defined, as exposure is limited away from the ridge top. Quartz veins protruding through boulders at lower elevations to the west locally contain galena-sphalerite clots and may be part of the same zone. A single chip sample (926923) from the Dexter Zone returned 5.2 grams per tonne gold and 42 grams per tonne silver over 2 metres (Assessment Report 31777).

Refer to Cummins Creek Veins prospect (093E 100) for common details of area work history.