The lower two members of the Kunga Group, consisting of the Upper Triassic Sadler and Peril formations, represent the main limestone resource of the Queen Charlotte Islands, particularly the basal massive grey limestone comprising the Sadler Formation. Its thickness varies from less than 30 metres to more than 200 metres.

The Kunga Group, consisting of the limestone members and an overlying argillite member, rests conformably on the Karmutsen Formation, and may be overlain conformably by the Jurassic Maude Group or disconformably by the Middle Jurassic Yakoun Group.

Limestone of the Sadler Formation outcrops over an elongate northwest trending steeply-sided hill 200 metres high. The limestone is exposed discontinuously over a length of two kilometres and width of up to one kilometre. A sample assayed 54.17 per cent CaO, 1.79 per cent MgO, 1.16 per cent SiO2 and 42.4 per cent loss on ignition (Paulsen, 1982, page 3-1).

Consolidated Cinola Mines Ltd. briefly evaluated this occurrence as a source of neutralizing medium for its Specogna epithermal gold prospect (103F 034).