The area is characterized by rounded hills and flat-topped ridges (Thomas, 1970). The most prominent ridge is Black Mountain, which trends about 12 miles in a northerly direction and is underlain by Cretaceous granodiorite (Weber and others, 1978). A combination of augen gneiss, gneissic schist, and schist are to the west of Black Mountain. There is intense shearing and faulting at the contact between the metamorphic and intrusive rocks. This shearing is observed in the underground workings to the north and at the surface as pronounced saddle-like depressions across the spurs extending westward from Black Mountain. This shear zone trends roughly N 15 E. The lode deposits in the area are gold-bearing quartz veins in the shear zone. Most of the veining and alteration occurs in the shear zone, although some alteration and veining favors the intrusive rocks (Doyon Limited, 1998).
The geology at the Jackie Prospect is assumed to be similar to that of the Carrie Creek (BD010) area, the Blue Lead Mine (BD003), and Grizzly Bear Mine (BD018). The drainage of Granite Creek is interpreted to follow a fault. A thick organic layer in the area has made soil sampling efforts difficult. A small, weak Au and As zone was identified on the southern face of the hill north of the mouth of Granite Creek; samples contained up to 1,125 ppm Sb. The Granite Creek Lode is reported to be 3/4 of the way up Granite Creek on the north-facing slope (Doyon limited, 1998). No other information regarding the Granite Creek Lode is available. An occurrence noted by Thomas (1970) on the ridge between Wolverine Creek and Granite Creek is described as a sample of drusy quartz with sulfide from a vein 2.2 feet wide. An assay from the sample showed 0.06 ounce/ton Ag and 2.39% Sb (Thomas, 1970).The Goodpaster region was first explored for placer gold in 1915. In the early 1930s, gold-bearing quartz veins were discovered in the upper Tibbs Creek (BD040) area to the south. Thomas (1970) performed some limited exploration of the Tibbs Creek area. In 1997 and 1998, exploration efforts on the Jackie prospect included stream-sediment, soil, and rock-chip grid sampling. Information regarding exploration and/or production from the Granite Creek Lode was not available (Doyon limited, 1998).