关于这张图
STS058-91-058 (18 Oct-1 Nov 1993) --- In this unusually clear view, the Ouachita Mountains of southeastern Oklahoma are framed on the north by Lake Eufaula on the South Canadian River, and on the south by the Red River. Sandstone, shale and chert (similar to flint) deposited in a sea several thousand feet deep were squeezed up to form the mountains about 250 million years ago. During the ensuing time, erosion of the western end of the Ouachita Mountains has emphasized linear ridges of resistant rock in the plunging anticlines and synclines, causing relief of 800 meters (2,600 feet) or more. …
