The region is underlain by (?)Hadrynian to Paleozoic Snowshoe Group rocks, which occur within the Barkerville Terrane of south-central British Columbia. These metasedimentary rocks consist primarily of marble, quartzite and phyllite which in this area comprise the Keithley and Harveys Ridge successions but which further to the east are undifferentiated. Metamorphism of the region varies from chlorite grade to sillimanite and higher. The lode gold deposits of the region occur in rocks metamorphosed no higher than greenschist facies.
The Plateau d'Or showings are between 1707 and 1737 metres elevation near the head of French Snowshoe Creek and about 914 metres northeast of the Jim adit (093A 037). The showings at one time were on claims held by P. Gorrie (Bulletin 34).
Mineralization consists of minor galena and pyrite within quartz veins cutting quartzite. The larger quartz veins comprise a subparallel set striking to the northwest. Gold and silver are associated with the sulphide mineralization. A 2.6 metre channel sample across the Plateau D'Or West vein assayed 9.59 grams per tonne gold, 219.26 grams per tonne silver, and 7.6 per cent lead (Geological Survey of Canada Paper 38-16, page 36).
The two veins are in an anticline of black silty quartzite near its eastern contact with basal and lower Snowshoe Group conglomerate and grey quartzite. The veins are exposed in several large opencuts. The two main veins are in black silty quartzite and lie in faults which cut across the dip of the cleavage but which seem to be parallel in strike to the enclosing rocks. They are close to the contact with grey gritty quartzite which overlies the black slates and silty quartzites and which oucrops in a band lying downhill to the east.
Both main veins are exposed in a long opencut at the northern end of the showings (ca. 1954). The eastern vein appears to be the more continuous and occupies a fault which strikes 335 degrees and dips 80 degrees to the northeast, cutting across the 040 degree northeasterly dipping beds. Drag structures suggest that the downthrow side is on the east. This eastern vein is about 0.9 metre wide in the opencut and reaches a maximum width of 2.4 metres in outcrops 15 metres to the south. It is exposed in opencuts on both sides of a draw 38 metres to the south. On the north side of the draw the vein is about 1.2 metres wide and is seen to contain a small amount of pyrite. A selected sample of quartz containing about 10 per cent pyrite and some lacy-textured marcasite assayed nil gold (Bulletin 34). On the south side of the draw, vein quartz having a width of 1.2 metres at surface pinches out at a depth of 2.4 metres. The southernmost exposure is 73 metres south. There, what is presumed to be the east vein, about 0.6 metre wide and striking 335 degrees, is joined from the southwest by a vein 61 to 71 centimetres wide, striking 065 degrees, and mineralized with black sphalerite and galena in irregular concentrations. Several opencuts farther south do not appear to have encountered any vein quartz. The west vein is exposed in the large opencut at the north end of the showings. It is 9 metres west of the east vein, is 1.4 metres wide, strikes 335 degrees, and dips vertically. About 18 metres south, a 0.6 metre quartz vein is exposed in an opencut, and 29 metres further south and about 7 metres west of the east vein there is a large amount of vein quartz which has a maximum width of 2.4 metres. In 1954, only a width of 0.7 metre is evident and the quartz is honeycombed with cavities from which pyrite has been leached, and is mineralized with some galena. The west vein is not traced south of this point, and even its northward continuity between opencuts may be uncertain.
In 2004, the Shear Gold claims covered the showing and structural geological measurements and 4 rock samples were taken on behalf of Golden Cariboo Resources Ltd.
