Cenizo Journal Winter 2013 | Page 25

The vapor was condensed and stored in metal flasks for transport. Mercury is one of the easiest metals to extract from its ore, and yet its refining took a heavy toll on the Big Bend ecosystem, as all available timber within an ever-widen- ing radius of the mines was rapidly exhausted. Eventually a low-grade source of coal was discovered nearby, from which a methane gas could be pro- duced to fuel the furnaces. Mercury is toxic, especially in vapor form, and the discarded slag from mercury mines con- tain a high level of the metal, as the pro- cessing of the ore typically yielded about 95 per cent of the mercury, leav- ing five per cent in the slag. Because of its volatility, any deposited mercury can be readily re-emitted to the atmosphere and the immediate environment. When one thinks of 19th century mining in the West, one thinks immedi- ately of precious metals - of silver and gold, boom towns, major population redistribution and a general rush toward the promise of riches. While the Big Bend saw nothing like the rushes experi- enced in California, it had its fair share of precious metal mining. The Shafter mining district was mined for precious metal ores, primarily silver, from 1883 until 1952. In 1876, geologist Samuel B. Buckley surveyed the Chinati Mountains and found deposits of silver, lead, copper, uranium, zinc and mercury. In 1879, three railroads – the Galveston, Houston and San Antonio, the International-Great Northern and the Texas and Pacific – organized a prospect- ing expedition to Presidio County, which came back empty-handed. In 1880, Col. William Shafter assayed a sample of rock brought to him by John W. Spencer, a local rancher. Having found small amounts of silver in the sample, the two teamed up with Lt. Louis Wilhelmi and Lt. John L. Bullis from Fort Davis and purchased four sections of land around Spencer's discov- ery. Lacking the technical knowledge nec- essary to mine the silver, however, they eventually leased and later sold the acreage to speculators from California, who organ- ized the Presidio Mining Company. Ninety-two per cent of the silver and 73 per cent of the gold produced in Texas during its years of operation came from the Presidio mine. At its peak it employed 400 miners and in 1913 it introduced air drills to make the work more efficient. The mercury-based mill, which extracted the silver from the ore by crushing it and mixing it with mercu- ry and salt, was replaced with a bigger and better cyanide-based mill. This process of chemical separation involves the fine grinding of high-grade ores, which are soaked in cyanide in vats, and the piling of lower-grade ores which are sprayed with the cyanide. The cyanide dissolves the silver and the slag, or spent ore, is discarded. Careful management of mine tailings and water in modern min- ing operations prevents cyanide pollution of mining areas, but spills of cyanide- polluted water can still occur and are common around the world. Shafter and the mining district flourished until the Great Depression, when the price of sil- ver took a severe downturn. Efforts to revive its glory days subsequent to 1936 failed as the output of silver and lead diminished steadily. Today, the Rio Grande Mining Company has reopened the silver mine at Shafter, building on exploration from the 1970s which occurred before the last decline in the price of silver. Using chemi- cal leaching to extract the precious metal, the mine intends to produce 3.8 million ounces of silver per year, roughly half the amount produced by the current largest producer in the U.S., in Alaska. The price of silver has tripled since 2009 to roughly $30 per ounce. The new Shafter mine will produce its silver in 800 pound bars. Concerns about the environmental implications of the mining extend beyond the use of chemicals and the safe disposal of contaminated slag. The Rio Grande Mining Company has announced its intentions to void approximately 1 million gallons of water per day into a nearby dry arroyo. Mining and controversy go commonly hand-in-hand: on one hand towns spring up in the desert, where a dearth of resources prevented their growth in the past. Jobs are created, as well as wealth, and a certain sense of conquering a stingy and inhospitable environment by wringing it for its underground riches. On the other hand, the extraction of resources through mining takes a bitter toll on the other resources of the desert: water, timber, and topsoil, the paucity of which already strains the ingenuity of this harsh environment's inhabitants, human and non-human alike. Yet the pursuit of riches in the ground is perhaps inevitable, as attested by the Burro Mesa quarries at the foot of the Chisos Mountains, where thirteen millennia of treasure seekers have mined before. NOW OPEN Accepting new patients Walk-ins welcome Se habla Español 2600 N. Hwy 118 (in the Medical Office portion of the Hospital) Monday through Friday • 8:00am to 5:00pm Dr. Catherine Harrington Family Practice / Fellowship-trained OB Board Certified Family Practice Dr. Harrington is a Magna Cum Laude graduate of the Meharry School of Medicine in Tennessee. She has a special interest in pedi- atric patients and OB’s. To make an appointment with Dr. Harrington, please call 432-837-0431. Dr. Rochelle Sohl Gynecology and Gynecologic Surgery Board Certified OB/Gyn Dr. Sohl is an Honors graduate from the University of Texas San Antonio. She is an Alpine native and has special interests in menopause, pelvic floor surgeries and women’s health issues. To make an appointment with Dr. Sohl, please call 432-837-0430. Allison Ainsworth, ANP Allison Ainsworth is an adult nurse practitioner who offers primary care for men and women over the age of 13. Allison received her MSN while working at Massachusetts General Hospital in Boston. She has worked with over 3,500 patients and also has experience in supervising care for a Nursing Home. Cenizo First Quarter 2013 25