The area is underlain by Lower-Middle Jurassic Dewdney Creek Formation (Ladner Group) tuffaceous sediments comprised of volcanic sandstone, siltstone, wacke, tuff and argillite with interlayered fossiliferous limestone. These rocks are separated from the Lower- Upper Cretaceous Pasayten Group sediments to the east, by the major northwest trending Chuwanten fault.

The Hall's showing is hosted by bedded quartzite which trends 090 degrees. The quartzite consists of alternating grey and limonitic bands which are highly fractured and blocky in places. Fine-grained pyrite is disseminated throughout the grey bands while the oxidized limonitic bands host some disseminated sphalerite and galena. Several opencuts were excavated in the oxidized bands. In 1913, a sample taken across 1.2 metres assayed 0.69 gram per tonne gold and 24.0 grams per tonne silver. In 1985, a grab sample from the oxidized, rusty bands yielded 70.97 grams per tonne silver (Assessment Report 14714).