The Quesnel area is underlain by Tertiary sedimentary and volcanic rocks which rest unconformably on rocks of the Cache Creek Group. The Tertiary rocks comprise a lower assemblage of sandstone, shale and conglomerate with interbedded tuffs probably of Oligocene age, overlain by Miocene plateau basalt.

The Baker Creek showing is located on the south bank of the creek, 4.8 kilometres above the highway bridge. The showing comprises soft white shale with cone 15.5, suitable for brick manu- facture if close firing clay was added. This deposit is probably the result of weathering of Oligocene shale.