Silver has been won from narrow vein faults in the Keno Hill district for nearly 70 years. During this period, 3.9 million tonnes (4.3 million tons) of ore have yielded 5754 million grams (185 million ounces) of silver. All of this production has come from sub-cropping ore shoots; supergene enrichment is not an important factor in most deposits. Parallelsim of the ore zone with the present surface has been seen in other Cordilleran vein camps, but despite considerable effort, operators in these camps have met with little success in their search for blind ore shoots.
The potential for blind ore in the Keno Hill district is examined from the perspective of metal-ratio zonation. An approximate reconstruction of the original fracture pattern in the district and the metal-ratio definition of a hydrothermal system acting within these fractures suggest that some ore shoots have been eroded, some are exposed at the present surface, and others remain preserved at depth.
