The Ashland district is between lat 42Â°01' and 42Â° 11' N. and long 122Â°31' and 122Â°48' W., in south-central Jackson County.
Mining began here in 1858 (Winchell, 1914b, p. 77) when placers were discovered at Forty-nine Diggings. These were highly productive for about 20 years. Lode deposits were worked as early as 1890, and the chief producer was the Ashland mine which yielded about $150,000 in gold from 1892 to 1899 (Winchell, 1914b, p. 77). The total production of this mine was estimated to be worth $1,300,000 (Oregon Department of Geology and Mineral Industries, 1943, p. 25). There was sporadic activity in the district up to 1942, but only a few ounces have been reported since that time. Production of the district from 1933 through 1959 was 1,764 ounces of lode gold and 163 ounces of placer gold. Total production through 1959, including estimates of early production, was about 66,400 ounces of gold. At Forty-nine Diggings, the major placer mine in the district, Quaternary gravels were originally mined, but productive channels were also found later in conglomerates of the Cretaceous Hornbrook Formation (Anderson, 1914, p. 90-93). Other placers were in the Quaternary gravels along Bear Creek and its tributaries.
GOLD HILL DISTRICT
The Gold Hill district is between lat 42Â°23' and 42Â°43' N. and long 122Â°47' and 123Â°15' W., in northwestern Jackson County, and includes the Foots Creek area.
Placers were worked in the district as early as 1853, but the big strike occurred in 1859 when lode gold was discovered; an estimated $400,000 was mined from the Gold Hill pocket in the first year (Winchell, 1914b, p. 154). The chief lode mines in the district were the Braden, Sylvanite, and Whitney. The lode deposits were important in the early days, but, with the exception of the Sylvanite mine, they were small though rich and were quickly mined out. The placers on Foots, Sam, Galls, Sardine, Evans, and Pleasant Creeks were worked on a fairly large scale for many years. Dredges and hydraulic methods were in use from the early days until as late as the early 1940's (Oregon Department of Geology and Mineral Industries, 1943, p. 42). The district was active on a small scale as recently as 1957.
Complete early production data could not be found. Parks and Swartley (1916, p. 109, 193) reported that total production from the Gold Hill pocket was at least $700,000 in gold, and the Revenue pocket is said to have produced $100,000 in gold. From 1908 through 1959, scattered production data totaled 2,847 ounces of lode gold and 35,021 ounces of placer gold. Total gold production through 1959, including the estimated early production from the Gold Hill pocket, was a minimum of 80,000 ounces.
Metavolcanic rocks of Triassic age are the most abundant country rock in the Gold Hill district (Wells and others, 1940). These were intruded by masses of peridotite and granite, and considerable folding and thrusting accompanied the intrusions. Conglomerates and arkoses of Cretaceous age cover parts of the area, and Tertiary sediments occur in the central part of the district. The veins are genetically related to the granitic intrusive and occur in it or in the surrounding Triassic sediments.
The veins consist of quartz lenses in fractures a few hundred feet long (Wells, 1956). In many veins, crushed rock fills the fractures between quartz lenses. The ore zones consist of mineralized quartz or crushed rock, commonly accompanied by seams and masses of chloritic material. Most of the gold is free and unassociated with sulfides, but in some veins pyrite, pyrrhotite, and minor galena and sphalerite may constitute as much as 3 percent of the ore.
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