National Geographic : 1971 Jul
Ore seekers blanketed the country with claims, sometimes staking the same ground three or four deep. Speculators fattened; min ing companies proliferated. Trading and prices of stocks outran comprehension. Ore output caught up with demand by the late 1950's, and the boom tapered off. Some oil wells and a big potash mine helped take up the slack, but Moab lost about a thousand of its swollen population-and the fever edge of its faith in instant fortunes. Upheaval Dome Resembles a Moonscape Every property owner in Moab would be a millionaire if salt became dear, for only 300 feet or so of alluvial deposits separate their basements from solid salt. A salt deposit as big as Maryland and as much as two-and-a-half miles thick underlies southeast Utah and part of Colorado, a legacy of landlocked seas. Lighter than the rock 82 above it and like putty under pressure, the salt rises into faults or other weakened areas, warping the surface upward. Where subsur face water invades the salt, it dissolves, letting the surface drop. The vast cracks in the sur face make it vulnerable to the erosive forces of sun, wind, rain, and the two great rivers, creating the land's fantasies in stone. Thou sands of columns, spires, buttes, arches, al coves, and headstanding stones pepper the map with curious names-the Doll House, Angel Arch, Six-shooter Peaks, Paul Bunyan's Potty (page 79), Land of Standing Rocks. Salt in fact is responsible for Moab's valley; welling up along a fault, it lifted and frac tured the surface. The salt later receded, leav ing a vast sheer-walled trench. But the salt's most awesome creation is a three-mile-wide bull's-eye called Upheaval Dome. "Some scientists thought it was a me teor crater," Dr. Richard B. Mattox told me.