A steeply dipping limestone mass of the Middle Triassic Brooklyn Formation outcrops north of the Mother Lode Mine (82ESE 034), 3.5 kilometres northwest of Greenwood. The limestone extends north-northwest from Deadwood Creek for 1100 metres and varies up to 400 metres in width. Massive chert of the Permo-Carboniferous Knob Hill Group outcrops to the east. Conglomerate of the Brooklyn Formation underlies the limestone to the west. A small stock of the Middle Jurassic Nelson Intrusions cuts the limestone mass near its south end.

The deposits consist of massive, irregularly jointed, medium to fine grained, grey to white limestone, that is cut by numerous white calcite veinlets. Rounded, light to dark grey chert nodules and thin beds of cherty "jasperoid" are sometimes present. Pyrite occurs in trace amounts. Actinolite, garnet, epidote and other calcium silicates replace some of the limestone near its south end in the vicinity of the Mother Lode Mine. A sample of white, crystalline limestone from the 200 foot level of the Mother Lode Mine contained 96.35 per cent CaCO3, 1.43 per cent MgCO3, 0.60 per cent insolubles, 0.20 per cent Al2O3+Fe2O3 and 1.32 per cent undetermined compounds (water, etc.) (Geological Survey of Canada Memoir 19, p. 19, Sample 2).