The following description is slightly modified from Assessment Report 21318: "Mama Susu-D, E and F shwoings (104B 373, 374, 375) are all located in a small valley containing an outflow stream fed by an icefield, and are separated from each other by varying widths of less intensely altered (sericite - calcite - chlorite - limonite) andesitic pyroclastics and siltstones. They consist of shear zones 30, 20 and 50 metres wide separated by 70 and 100 metres respectively, all striking northeast-southwest. All are very strongly to completely altered to sericite with auxiliary quartz and disseminated pyrite (up to 5 per cent). Locally they contain pockets of massive sulphides with galena (up to 30 per cent), pyrite (up to 50 per cent), limonite (up to 50 per cent), sphalerite (up to 10 per cent) and minor stibnite, wad and malachite-azurite staining.

Gold and silver results from Mama Susu-F were low, ranging from 20 parts per billion to a high of 550 parts per billion gold in massive sulphide (#46017) and two significant silver assays of 11.18 ounce per ton (#46014) and 53.53 ounce per ton (#46017). Base metal results were lower than expected except for select grabs which assayed as high as 42.70 per cent lead (#46017) and 9.16 per cent lead (#34531). Copper values were low except for sample #46017 which assayed 6058 parts per million. Zinc returned three strongly anomalous values of 5.16 per cent (#46017), 6.72 per cent (#34530) and 8.29 per cent (#34531). Samples #34530 and #34531 consisted of mineralized silicified siltstone and andesite tuff respectively."

According to Open File 1991-21 this showing occurs in the Unuk River Formation of the Lower Jurassic Hazelton Group, slightly below the contact with overlying Betty Creek Formation strata. Fossils found approximately 400 metres to the south of the showing in rocks that are apparently correlative and along strike, indicated a Hettangian to Sinemurian age.