The Bigtime B occurrence is located just southwest of Ominicetla Creek about 200 kilometres northwest of the community of Fort St. James.
The Bigtime B showing area is underlain primarily by the Lower Jurassic Telkwa Formation (Hazelton Group) consisting of a sequence of subaerial to submarine calc-alkaline island arc volcanic and sedimentary rocks. Cretaceous to Eocene volcanic and sedimentary rocks of the Sustut Group are also present. The Telkwa Formation rocks are intruded by small plugs of quartz and hornblende feldspar porphyry of unknown age and a large plug of biotite hornblende diorite of Late Jurassic age.
Porphyry-style mineralization has yielded samples with up to 0.46 per cent copper and some elevated molybdenum . Samples are described as quartz porphyry intrusions containing chalcopyrite and malachite staining throughout weathered iron oxide. Up to 4596 parts per million copper was obtained from samples of intrusions (and locally volcanics) with disseminated pyrite, chalcopyrite, and malachite. Molybdenite was not observed in any of the samples collected, but a maximum of 186.2 parts per million molybdenum was obtained from a felsic dike with 1 per cent disseminated and banded pyrite (Assessment Report 31410).
In 2009, Amarc Resources Ltd. completed a program of geological mapping, prospecting, rock (184) and soil (519) sampling, and an induced polarization survey (11.7 kilometres).
See Lion (093M 146), located 1.6 kilometres north, for details on the Bigtime B work history.