The Ozzna Creek prospect consists of base metal sulfide veins and replacement deposits in an extensive quartz-sericite-pyrite halo rimming a 450-meter-wide, quartz-monzonite breccia pipe,. The pipe forms the core of a distinctive, precipitous, 7,205-foot -high peak. A biotite separate from the quartz monzonite pipe gave a K-Ar age of 58 Ma. (Solie and others, 1991). A pronounced magnetic high rims the edge of the breccia pipe (Rob Kell, written communication, 1983). (The magnetic anomaly that rims the quartz monzonite breccia pipe is similar to geophysical features found in porphyry copper systems throughout the North American Cordillera.)

The vein and replacement deposits consist of small pods and lenses of pyrrhotite, sphalerite, argentiferous galena, and pyrite in a gangue of carbonate, epidote, and quartz along shear zones in felsic dikes and igneous breccia. Most of the sulfide pods are from 0.2 to 1.5 meters wide and 0.5 to 6.0 meters long. Selected samples contained 1,623 to 2,189 grams of silver per tonne (Reed and Elliott, 1968).

The quartz-sericite-pyrite halo that surrounds the quartz-monzonite breccia pipe is from 15 to 60 meters wide and can be traced along strike for about 450 meters. Disseminated chalcopyrite and traces of molybdenite occur in pyrite-rich igneous breccia. Selected samples from the quartz-sericite-pyrite halo contain up to 0.08 percent copper, 150 parts per million molybdenum, 1.50 percent lead, 1.00 percent zinc, 14.6 grams of silver per tonne, and 2.48 grams of gold per tonne. (Bundtzen, Kline, and Clough, 1982; Bundtzen, Harris, and Gilbert, 1997).