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Mountain-building is alive and well in the western United States. At Bat Mountain near Death Valley Junction in eastern California, tilted layers of the white eureka quartzite lie beneath the black Ely Springs Dolomite; both were deposited about 460 million years ago. The rocks have been tipped up as the Basin and Range Province actively continues to stretch and thin. |
 The cliffs of Red Rock Canyon tower over the Mojave Desert near Las Vegas, Nevada. In a normal world, younger rocks would overlie older ones. But here, limestone of the older Bonanza King Formation has been thrust over the younger Aztec Sandstone along the Keystone Fault, turning time upside down. | |||