Yukon Region Alaska Gold Production
The Ruby district is between lat 63°40' and 64° 45' N. and long 154°40' and 156°20' W.
The first discoveries of gold in this district were made in 1907 along Ruby Creek (Mertie, 1936, p. 144). These placers were soon exhausted, but other discoveries in 1910 along Long Creek and in 1912 along Poorman Creek kept the district flourishing (Mertie, 1936, p. 145, 159). Underground drifting, sluicing, and hydraulic methods have been used to mine the gravels. Although production decreased somewhat in recent years, the district was still producing substantially through 1959. Total gold production through 1959 was 389,100 ounces, all from placers.
Undifferentiated metamorphic rocks, including schist, phyllite, slate, quartzite, chert, and limestone, are mainly of Paleozoic age and are the predominant bedrock types in the Ruby district (Mertie and Harrington, 1924, p. 12). A complex of greenstone derived from basic igneous rocks, be¬lieved to be Mississippian in age (Mertie and Harrington, 1924, p. 59), is exposed throughout the district. A few granite stocks of Mesozoic(?) age intrude both the Paleozoic rock units. The generalized structure is an anticline trending northeast and plunging to the southwest.
Numerous quartz veins are in the country rocks; some undoubtedly contain gold and could be regarded as the source of the gold in the placers. The distribution of the placers, however, does not directly coincide with areas of abundant veins, so that no clear relationship is apparent (Mertie and Harrington, 1924, p. 121). Nearly all the placer deposits are buried discontinuous bodies that occur mostly in fairly wide valleys. They were formed by streams older than those now occupying the valleys (Mertie, 1936, p. 144).
RICHARDSON DISTRICT
The Richardson (or Tenderfoot) district is between lat 64° 15' and 64°25' N. and long 146°00' and 146°40' W., about 60 miles southeast of Fairbanks, along the Tanana River.
This is a little-known district, about which only a few brief accounts have been written. According to Prindle (in Prindle and Katz, 1913, p. 141) gold was discovered in the gravels of Tenderfoot Creek in 1905 and for the following 4 years the gold production was probably "$300,000 or $400,000 annually." Smith (1933, table facing p. 96), however, reported a much more conservative figure. Productive deposits also were found along Buckeye and Democrat Creeks. Activity declined after the initial boom period and in recent years the production, which is low, has been combined with that of the Fairbanks district. Total recorded production for the district through 1959 was 64,300 ounces, all from placers.
Prindle (in Prindle and Katz, 1913, p. 140-141) noted that the bedrock in the district is Birch Creek Schist of Precambrian age (Mertie, 1937, p. 46). Numerous small quartz veins, some of which carry gold and sulfides, occur in the schist. Just west of the district are some large granitic masses (Prindle, in Prindle and Katz, 1913, p. 140-141). The placers are along present streams in the area.