The Sawmill Creek area is underlain by quartz diorite and granodiorite assigned to the Early and Middle Cretaceous Spuzzum Intrusions.

In the area of the Pipe occurrence, biotite quartz diorite has been intruded by three breccia pipes with associated rhyolitic phases. The breccia comprises fragments of coarse-grained quartz diorite, rhyolite and porphyry supported by a fine-grained matrix of quartz diorite, quartz and limonite. Vugs lined with pyrite and quartz crystals are common.

Iron sulphides "with modest copper and molybdenum content" are associated with quartz stockworks within the pipe(s). This mineralization is both disseminated and occurs as irregular blebs within vugs. Minor sphalerite has also been observed locally.

From diamond-drill hole SC-79-2, a two-metre long interval of granodiorite-quartz diorite breccia containing subparallel quartz-pyrite veins carrying molybdenite assayed 0.136 per cent MoS2 (Assessment Report 7552).