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Show dome between the two mountain chains. Then the dome cracked up, collapsed. Between the cracks some blocks of rock tilted to form the desert ranges that slow you down as you drive east and west on some roads across Nevada. The fractures did more than make high ridges such as Nada's main landmark, our long western wall Blue Mountain. They opened vents to let heat out from under earth's crust. From the hot heart of the globe comes super-heated steam, original moisture spurting out of material that could be lava if weight were relieved sufficiently, When other water from nearer the surface seeps into the fractures, it also gets heated. Then both it and the deeper steam rise up as hot springs and geysers such as Old Faithful in Yellowstone. The faults, then, explain the Hot Springs near Nada. The Springs were our most fascinating scenic feature and, in odd ways, the center of community life. They were more than natural teakettles boiling over with smelly mineral water. They hinted deep mysteries. At Nada two cracks occurred close together in earth's crust. So the Hot Springs rise along two seams in the underlying rock. The boiling water dissolves minerals from the rocks on its way up. Partially cooling, it dumps some of its chemical load. Thus it builds two narrow mounds which run side by side for a mile. The Union Pacific angles over the north end of those mounds. Once a freight conductor inspected the Springs. Because his job had given him experience with dry bearings or "hot boxes" smoking on freight car axles, he produced this whimsy to explain the fuming Hot Springs: "They're water SOMEBODY uses to cool a hotbox on the |