The Jefe showing area is underlain by marine sedimentary and volcanic rock of the Upper Triassic Stuhini Group. The stratigraphy is intruded by Eocene granite of the Major Hart Pluton and Early Jurassic monzodiorite to gabbro of the Texas Creek Plutonic Suite. Further west the area is underlain by Devonian to Permian sedimentary rocks of the Stikine Assemblage.

The Jefe zone to be underlain by massive, grey, aphanitic, andesitic crystal tuff (unit 8E) hosting minor pyrite pyrrhotite disseminations. The tuff is variably fractured and sheared with limonite fracture infillings. It strikes south-southeasterly with a moderate to steep southwesterly dip. All quartz veins are structurally controlled and are recessively weathered. The shears hosting significant quartz veining trend at 150 to 165 degrees with steep southwesterly dips. These tend to diverge southeastward, and become narrower and less mineralized.

Hand trenching in 1991 revealed narrow limonitic shear zones that hosts sulphide-rich quartz veining within grey, medium-grained crystal tuff. Pyrite plus or minus pyrrhotite occurs as disseminations, fracture coatings, and associated with quartz in the larger shears. The trenching extended the gold mineralization over a north-south strike length of 70 metres from trench Tr 90-01 southwardly to trenches Tr 91-05 and Tr 91-06. The shear structure which hosts the gold-bearing mineralization splays into several branches north of trenches Tr 91-05 and Tr 91-06. It continues southwardly for another 50 metres to trenches Tr 91-07 and Tr 91-08, but here it hosts much lower gold values.

A 1 metre chip trench sample assayed 13.10 grams per tonne gold and 27.6 grams per tonne silver (Assessment Report 21928).

Refer to the Rolls Royce showing to the immediate north for details of a common work history.