The occurrence is in the Yukon-Tanana Terrane in southeastern Yukon, which is composed of a penetratively deformed volcano-sedimentary assemblage. These rocks have been intruded by contemporaneous meta-gabbro sills and a group of Palaeozoic plutonic and meta-plutonic rocks. Cretaceous to Tertiary aged volcanic, sub[1]volcanic and plutonic rocks intruded the package of rocks. 

Two phases of deformation with regional metamorphism are recognized in Yukon-Tanana Terrane in the region. The regional metamorphism is in the green schist to lower amphibolite facies. The sub-horizontal foliation is sub-parallel to the compositional layering. The foliation in the RB area strikes west to northwest and dips gently to the north and northwest.

There are four main meta-sedimentary or meta-volcanic rock units mapped on the RB property. The oldest unit is quartz schist and micaceous quartzite with lesser quartz-pebble conglomerate and chlorite-biotite schist and grey carbonaceous quartzite. Overlying this unit is a meta-volcanic unit that consists of massive bedded calcareous plagioclase-chlorite-biotite-actinolite schist interlayered with weakly layered plagioclase-chlorite-biotite-actinolite schist and minor carbonaceous phyllite and quartzite. Above that is light grey, tan to white thin platy quartz-muscovite schist with local small scale augen of quartz and feldspar. This unit occurs near the contact of the underlying meta-volcanic unit locally within the overlying carbonaceous unit and indicates felsic volcanism at the end of the mafic volcanic activity and transition to the sedimentary deposition. 

The uppermost, and presumably youngest rocks on the property are medium to dark grey carbonaceous muscovite-quartz schist or phyllite, quartzite with rare light grey marble.

The meta-volcanic unit hosts the mineralization, which consists of magnetite and sulphide. The JD showing consists of coarse grained euhedral black magnetite crystals, up to six millimeters, that occur along bands of strongly foliated chlorite schist. Pyrite and rare chalcopyrite grains are disseminated along thin horizons within the foliated schist. The showing occurs in an outcrop two meters tall and five meters long. Large talus blocks of mineralized schist can be trace for 30 meters. Channel samples yielded values of 0.184 g/t gold and 672 ppm copper over 65 centimeters. The upper half of the interval yielded 0.248 g/t gold and 1 335 ppm copper. The lower half of the interval assayed 0.068 g/t gold and 365 ppm copper.