| Escalante Canyons, Utah. Late-afternoon storm clouds boil up over Fifty-Mile Mountain and a sandstone basin filled with countless small concretion spheres. Although these golf-ball-sized nodules may be seen scattered all across the Colorado Plateau, this is an especially rich deposit. These spheres were formed by small impurities within the almost pure-quartz sand which formed the dunes covering this area 190 million years ago. As groundwater percolated down through this sand, these particles attracted dissolved minerals in the water and begin to form these nodules. Much harder than the surrounding sandstone matrix, they eventually erode out and are left on the surface of the much softer Navajo sandstone. All photos in these galleries may be ordered as fine art framed prints or for stock photography usage. |
