National Geographic : 1968 May
curving terraces and ledges on which yellow trucks moved like Tinkertoys. A sign read "Carlin Gold Mine-No Trespassing." The gold strike that made this scene a real ity, General Manager Arthur C. Hilander was shortly explaining, rests below a peculiar geo logic formation known as the Roberts Moun tain thrust fault. Along a belt hundreds of miles long, rock layers of different ages slid one above the other, like shingles on a roof, during a shift in the earth's crust. Humped into ridges later, the upper fault layer here and there contains "windows," where upper rocks have eroded away to ex pose the lower layer. It was these windows, and the possibility that the lower fault layer might contain minerals, that the U. S. Geolog ical Survey noted in a brief report in 1960. In great secrecy, intrigued by the report, Newmont Mining sent geologists to take a look. John S. Livermore and Robert B. Fulton began prowling and sampling the worn ridges of the Tuscaroras. They said as little as pos sible about their work. Their samples were assayed in an old shack 50 miles away. Harry Treweek, a veteran of 30 years of Nevada gold mining, ran the assays. Today he is chief assayer at the Carlin Mine. "My wife and I ran hundreds of tests," he told me. "Even we didn't know where the samples came from. But they held gold, too fine-grained to be seen by eye" (page 668). Crews Drill for Invisible Wealth Encouraged, Newmont filed claims on six square miles of public land in the Lynn Creek district. In mid-1962 the company sent in drill crews. Peter N. Loncar, now mine boss at Carlin, headed one of them. "We put down two test holes and hit noth ing," Pete told me. "The third time, we drilled into a large ore body of invisible gold." Newmont contracted for a multimillion dollar extraction plant designed by one of its vice presidents, F. W. McQuiston, who gained his experience in the historic Mother Lode and Grass Valley gold fields of California. Then 500 construction workers poured into Carlin. In ten months they built the mill, stripped three million tons of overburden from the mountain of gold, drilled wells, and raised a dam to catch waste slurry from the plant. In May, 1965, the Carlin Mine was dedi cated and the first gold brick poured. New mont President Plato Malozemoff called it "a miner's dream." And so it still seems. Pete Loncar took me out into the vast pit, a mile and a half long and hundreds of feet 674 Ore moves by truck from pit to crushers. DUMPTRUCK VIBRATING SCREEN 00 JAWCRUSHERBREAKS SRE UP LARGERPIECES FEEDER CONE PASSES CRUSHER SMALL I PIECES \": r DIAGRAMBY GEOGRAPHIC ART DIVISION;PHOIUTRAPMHBT UAviu r. purr Electronic control panel monitors milling process. REMELTING FURNACE End of the line: A bar of bullion joins others in the safe. End of the line: A bar of bullion joins others in the safe.