The River Jordan Lead Zinc Revelstoke Mining Division, Deposit, B. C.

CIM Bulletin, 1961

A relatively unexplored lead z'nc depos'.t lies about 12 miles northwest of Revelstoke, B.C., in the highly metamorphosed Monashee Group of rocks of the Shuswap Terrane, Precambrian in age. Host rocks are of sedimentary origin and consist of g nei sses, schi st s, marbles and quartzites with intermediary types. The marbles and quartzites provide good horizon markers. Using these it is possible to interpret the controlling structure which is a syncline overturned to the north, dipping south at about 45 ° , and plunging east at about 12° . The syncline is truncated at about halfway of its length on a peak on the west side of which a partial cross section together with superimposed minor folds may be seen. The quartzites and the two marble beds may be traced over much of the structure. There are two lodes, above the marble and below the quartzite, which converge eastward and which are the exposed edges of the same host bed - an impure limestone. The south or No. 1 lo:le is the thicker and is considered to be the chief potential ore source. This lode is exposed at intervals for 7,200 feet from an elevation of 5,800 to 7,900 feet and has an average thi¢kness of 5 feet. Due to freshness of exposures, surface sampling was carried out on four separate sections of the No. 1 lode for a total length of 3500 feet without preliminary surface work of any kind. This rnmpling, together with the cross sectional exposures at the west end, permitted grade and rough tonnage estimates to be made of No. 1 lode, not counting the potential tonnages of the superimposed fold s. This was 2,873,000 tons having a grade of 1.1 ounces of silver, 5.1 per cent lead and 5.6 per cent zinc. There is evidence of zoning, part" cularly of the lead, zinc and local barite gangue with suggestions of a zinc envelope at the extremities of the lode. The syncline appears to have been truncated by erosion at about halfway of its length to the west. This, with the strength of mineralization at this place, suggests that it could have formed a lode originally 14,000 feet long and if it maintained its original width of 5 feet, which it could well have done, it would have been an almost unique deposit. Erosion appears to have re- moved over three million tons from the present No. 1 lode so that the original tonnage could have been 12,- 0tlO,OOO tons. Other deposits of great length in r elation to their widths are known in the Shuswap Terrane in both the Revelstoke and Kamloops Mining Divisions. The ease of preliminary evaluation is compensated for in difficulties presented to secondary stages of development due to paucity of good drill locations and length of cross cut tunnel to the lode. However, some drilling can be done in the central part and second steps should be taken at an early date so that production should not be unnecessarily delayed in case of an increase in lead and zinc prices
Keywords: barite, lode, sphalerite, syncline, zinc, Deposits, Lead, Marble, Rock, Rocks, Structure, Tonnage, zinc