Geologic map of the Northport quadrangle, Washington
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Robert G. Yates
Publications and source records attributed to Robert G. Yates.
Geology and quicksilver deposits of the Terlingua district, Texas
The Terlingua quicksilver district, which has produced more than 150,000 flasks of quicksilver, is in the southern part of the Big Bend region of southwestern Texas. It is a narrow, eastwest area about 20 miles long and lies mainly in southwestern Brewster County. The district is connected by graded road with the nearest railroad, 84 miles north of its center. Quicksilver minerals were first discovered in the district in the latter part of the 19th century, but there was no substantial production until 1900. Although there are about 20 mines and many prospects, more than 90 percent of the quicksilver came from the Chisos-Rainbow, Mariposa, and Study Butte mines. The most productive years were during World War I; since 1946 the district has been idle. Future production depends upon the discovery of new ore bodies-which will be costly-and the working of deposits now considered of too low grade to be profitable.
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248 mine, Terlingua quicksilver district, Brewster County, Texas
The 248 quicksilver mine is in Section 248, Block G-4, 2 miles east of Terlingua and 86 miles by dirt road from Alpine, Tex., the nearest railway shipping point (see accompanying maps). Cinnabar, the quicksilver mineral, was discovered before 1902. By 1934 there were only about 700 feet of subsurface workings, but in recent years the Esperado Mining Co., which has the property under lease, has greatly extended exploratory workings and has built a Herreshoff furnace rated at 40 tons per day. At the present time there are 1 1/3 miles of underground workings and 800 feet of surface trenches.
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The Mariposa mine, Terlingua quicksilver district, Brewster County, Texas
The Mariposa mine in Brewster County, Tex., ranks second in all-time production of quicksilver in the Terlingua mining district. It is in Section 59, Block G-12, and is about 7 miles by road west of the Terlingua Post Office (see accompanying maps). The nearest railroad shipping point is Alpine, Tex., which. is 93 miles by road to the north. The mine is now controlled by the Esperado Mining Co. of Houston, Tex. Since 1895 the Mariposa mine has produced between 20,000 and 30,000 flasks of quicksilver. The major production was before 1911, but the mine was active during the first World War, and again during the period from 1933 to 1942. In February 1944, the Esperado Mining Co, was reworking some of the old dumps and exploring an ore showing in the east wall of the Perry pit. The productive ground, a rectangular area roughly 3,500 feet long and 1,000 feet wide, centers about California Hill (see plate 1). The principal subsurface workings, about 3 miles of drifts, stapes, and crosscuts, are under California Hill, but much of the ore was taken from numerous pits, trenches, and shafts northeast and west of the hill. Of the 121 shafts over 20 feet deep, 6 are over 100 feet deep and. 2 of these, No. 5 (or Cruz) shaft and the finite shaft, are 300 or more feet deep. The Contratiro winze (see map of workings) extends 200 feet below the 100 level of the mine. Several thousand feet of drifts and crosscuts extending from the deeper shafts explore the mineralized ground through a vertical range of about 300 feet, but almost all the ore that has been produced came from the uppermost workings.
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