The La Sal Mountains, near Moab in southeastern Utah, are laccoliths formed when upwelling magma intruded into and bulged the overlying sedimentary rock layers upward. The magma did not reach the surface, but subsequent erosion of the softer sedimentary rocks exposed the peak-forming igneous rocks that rise above the surrounding landscape.
Tag Archive for: San Juan County
Blocky sandstone ledge deposited in an oasis-like setting between ancient sand dunes forms a resistant cap over beds of the Jurassic-age Navajo Sandstone. Chippean Rocks west of the Abajo Mountains, San Juan County.
The Owachomo Bridge was created by stream erosion of the Permian-age Cedar Mesa Sandstone. Owachomo, a Hopi term meaning “rock mound,” is named for the large rock mass found on the northeastern abutment of the bridge.