EAST BELT DISTRICT
The East Belt district includes a system of lodes parallel to the Mother Lode, about 10 miles to the east. The settlements of Pooleys Ranch, Soulsbyville, and Tuolumne are along the East Belt.
The first claims on the East Belt were located in the mid-1850's. The deposits proved to be extremely rich in gold, and before 1899 the yield of 38 East Belt mines was about $19,340,000 (about 938,800 ounces), a far greater output than that of the Mother Lode for this period (Julihn and Horton, 1940, p. 19). These veins, however, were for the most part shallow, and high production could not be maintained for any extended period. Nevertheless, the Soulsby mine has produced $6,750,000, and there are five other mines with a production of $1 million or more (Julihn and Horton, 1940, p. 52-53). Total production through 1959 of the East Belt in Tuolumne County was about 965,000 ounces.
The veins of this district are in and grouped around a stock of granodiorite that intruded the Calaveras Formation (Julihn and Horton, 1940, p. 51-52). Pegmatites cut both the granodiorite and Calaveras Formation, and the gold-bearing veins are later than the pegmatite. Most of the veins are in the granodiorite and along the granodiorite-country rock contact. The veins are narrow and they pinch and swell; nevertheless, they are remarkably persistent. Free gold is found in these veins with quartz and with sulfides which include pyrite, pyrrhotite, chalcopyrite, galena, sphalerite, and complex sulfides of lead and antimony.
The Groveland-Moccasin-Jacksonville area is in parts of T. 1 S., Rs. 14, 15 and 16 E., in southern Tuolumne County.
Before 1899, Quaternary gravels in this area yielded about $34 million in gold (Julihn and Horton, 1940, p. 69). There is no consistent record of later production, although Julihn and Horton (1940, p. 81, 82) reported dredging operations along Moccasin Creek in 1937 and 1938.
The Longfellow mine, the most productive of a group of lode mines near Groveland, produced an estimated $1/2 million in gold (about 24,200 ounces) before 1899. No record was found of any later lode mining in this district.
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