The Bighorn showing is located on the west side of Bighorn Creek just downstream from the junction with Chicken Creek.
Actinolite schist of the Devonian to Permian and older Boundary Ranges Metamorphic Suite is exposed on the upper slopes and dike-like feldspar porphyry is exposed in a narrow band along the lower slopes.
The lens-shaped veins primarily occur in a shear zone and are almost always conformable to the foliation of the hostrocks. The lenses, 5 to 61 centimetres wide and up to 61 metres long, are divisible into two groups formed at different times. The older veins are badly broken, faulted and almost barren. It appears that gold occurs in significant amounts only in younger veins. Mineralization consists of quartz, pyrite, galena and chalcopyrite with occasional free gold. A recovery of over $2000 was reportedly from small tonnages of selected ore mined at the tunnels several years before 1933.
The Bighorn mine is located along a secondary or tertiary splay of the Llewellyn Fault zone. Samples of the fluid inclusions show that the fluid was more saline but less CO2 bearing than usual gold producing fluids but quite hot (250+C.) as expected, for mesothermal veins.
A channel sample composite, across 35, 20.3, 22.9 and 35 centimetre vein widths at 1.5 metre intervals, west of the Little tunnel portal assayed 44.56 grams per tonne gold and 13.71 grams per tonne silver (Minister of Mines Annual Report 1933, page 80).
Work History
The property was staked in 1898. The Big Horn Group, consisting of the Big Horn, Little Bear, Gold Bird, Lucky Jack, Tyee and Bertha claims, was staked in 1909 by F. Lawsan and Assoc. In about 1910, a one-stamp mill was installed and small scale development occurred for several years. Two adits, the North and the Little, were driven for 17 and In 2007, a total of 544.4 line-km of airborne geophysical surveying, comprising magnetics and electromagnetics (EM), was completed over the Bighorn Property that included the Bighorn Creek prospect (Lawson vein) (104M 006) and the Bighorn showing (104M 007). The 2007 Airborne Geophysical Survey identified a number of magnetic and electromagnetic anomalies of interest that will require 'ground truthing' by prospecting in the field. Further prospecting and detailed sampling and mapping is required along the east side of Bighorn Creek east and south of the historic workings at the Lawson vein where an interesting pattern of radiating magnetic anomalies (many with corresponding EM anomalies). Also, a large north-south linear magnetic feature was identified on the west side of the survey area with some coincident EM features. The Lawson Vein appears to have been identified as a very subtle east-west anomaly in the 1st Vertical Derivative magnetic data and as a small but discreet conductive anomaly in the EM data.
In 2011, Dahrouge Geological Consulting Ltd conducted a exploration program on the Bighorn Property on behalf of operator Micrex Development collecting a total of 5 rock samples. The owner was indicated to be Gee Cee mines Ltd of Edmonton Alberta. The claim group covered the Bighorn showing area (104M 007) as well as the area around the Lawson vein at the Bighorn Creek prospect (104M 006).
