The Shasta Iron showing is located on the Summit claim between Skookum and Fish Creeks in southeastern Alaska.

Located in the Intermontane Belt, the area, bounded on the west by the Coast Crystalline complex and on the east by the Bowser Basin, is part of the Stikinia Terrane.

The showing is hosted by the Upper Triassic to Lower Jurassic Hazelton Group, Unuk River Formation metavolcanics. The Hazelton Group is a northwest trending steeply east dipping belt of folded andesitic lapilli tuffs, flows and breccia containing a thick se- quence of argillite and siltstone infolded along a synclinal axis. The sequence is intruded by the Early Jurassic Texas Creek plutonic suite of dacitic porphyry dykes and sills, Eocene granitic Hyder intrusives and lamprophyre dykes.

Mineralization is hosted in metavolcanics that have been sili- cified and sericitized. Petrography indicates that the original host may have been a quartz porphyry. Indistinct bedding trends 70 degrees northeast and is nearly vertical.

These altered metavolcanics contain calcite veins, quartz, chlorite, orthoclase and abundant sulphide mineralization, most notably large masses of almost pure pyrrhotite. The largest of these masses measures 1.52 by 3.66 metres with a vertical extent of at least 3 metres. Small amounts of chalcopyrite, arsenopyrite and pyrite are associated with these bodies.

The paragenetic sequence is thought to be pyrite, arsenopyrite, quartz, pyrrhotite and chalcopyrite with pyrrhotite and chalcopyrite occurring contemporaneously.

An assay of samples from this body was reported to contain 12.34 grams per tonne gold, 137.12 grams per tonne silver and 2 per cent copper (United States Geological Survey, Bulletin 807).