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 a broad peninsula extending from the north side of Skidegate Lake, 4 kilometres west of the east end of the lake. The limestone is exposed discontinuously over a length of 0.9 kilometre and width of up to 0.5 kilometre. The quality of the limestone is reported to be high and to be of similar character as the limestone comprising Skidegate Lake South (103G 047) on the south side of the lake (Paulsen, 1982, page 3-3).
Consolidated Cinola Mines Ltd. briefly evaluated this occurrence as a source of neutralizing medium for its Specogna epithermal gold prospect (103F 034).