THE CITY ROCKS! Explore the Hidden World of Building Stone

T HE C OMSTOCK L ODE: H OT W ATER AND H EAVY M ETAL

Introduction > Prologue > Building Stone > Flood Mansion

	The eastern edge of the Sierra Nevada, where the mountains rise sharply from the desert, has been volcanically active for millions of years. There are hot springs south of Mono Lake. At Long Valley, a collapsed volcanic crater or caldera, the ground swells and falls over thousands of years as melted rock, or magma, fills and empties a chamber beneath it. During volcanic activity, hot, acidic water associated with magma can dissolve metals from the surrounding hot rocks and bring them toward the surface. The water flows up through cracks and faults. As it cools, the metals precipitate out of the water and become solid masses in the cracks. About 12 million years ago, in a fault system at the foot of Mount Davidson in the Virginia Range of western Nevada, hot water rose from below and filled an enormous crack with gold, silver, zinc, lead, copper, and iron. The metals were either pure or sulfides (bonded with sulfur). The California gold rush of 1849 brought prospectors from the East. As they passed through Nevada's Carson Valley en route to California, some of them panned for gold. Few found anything except a heavy, bluish sand that they found a nuisance. Someone finally had the sand assayed in 1859 and found that it was silver sulfide, mixed with gold, and worth $4000 a ton. Prospectors bought claims that straddled the fault: the Ophir, Consolidated Virginia, Hale and Norcross, and others became famous. Virginia City's population exploded to 25,000 as the bonanza was dug out of the lode. Click here to see a map of the lode and the claims as they were in 1880. Eventually, James Flood and his three partners came to dominate the lode. They monopolized the local railroad, lumber supply, and other related businesses that the mines depended on, and owned some of the richest mines. Working the Comstock Lode was dangerous and exhausting. The mines eventually deepened to more than three thousand feet, and steep ventilation shafts had to be cut. The temperature at the rock face at 2200 feet was mines regularly exceeded 120 degrees Fahrenheit. Miners suffered and some died from the heat. Many developed silicosis from inhaling rock dust. By the 1860's, enormous air pumps forced fresh air through the mines, and the men used tons of ice every day to cool down; but even so, in the deeper mines, they could only work for fifteen minutes at a time. Yet the wages were so good that they stayed, and more came all the time. Virginia City was awash in money; at its peak it had hotels and restaurants as luxurious as those in New York, and its shops sold the best of everything. When the mines dried up, Virginia City's population fell drastically, and it nearly became a ghost town. Today, it's a historic site and a major tourist attraction.

Introduction > Prologue > Building Stone > Flood Mansion > Comstock Lode	Copyright © 1999; E.B. Keck