Paleozoic rock along the Colorado River in Grand Canyon National Park, Arizona. Tapeats Sandstone in the foreground up to Redwall Limestone in the...
Mixing line between the calcium carbonate laden Little Colorado River and the Colorado River, Grand Canyon National Park, Arizona.
Vishnu Schist and granitic intrusions in the Upper Granite Gorge of the Colorado River in Grand Canyon National Park, Arizona.
Travertine-covered rock and dissolved calcium carbonate in the Little Colorado River, Grand Canyon National Park, Arizona.
Colorful beds of the Cambrian Bright Angel shale overlain by travertine-cemented colluvium, Grand Canyon National Park, Arizona.
Karst. Dissolution of Mississippian Redwall Limestone by groundwater, Grand Canyon National Park, Arizona.
Exposure of the Permian Hermit Shale beneath cliffs of light-colored Permian rock and Colorado River, Grand Canyon National Park, Arizona.
Vishnu Schist with a cap of Tapeats Sandstone on the Great Unconformity, Grand Canyon National Park, Arizona.
Mixing line between the calcium carbonate laden Little Colorado River and the Colorado River, Grand Canyon National Park, Arizona.
Vishnu Schist and granitic intrusions in the Upper Granite Gorge of the Colorado River in Grand Canyon National Park, Arizona.
Trace fossils on underside of bedding plane, Cambrian Tapeats Sandstone, Grand Canyon National Park, Arizona.
Great Unconformity between the Cambrian Tapeats Sandstone and underlying Proterozoic Basement rock. Grand Canyon National Park, Arizona.
Channel deposit cut into the underlying basement rock at the Great Unconformity, Grand Canyon National Park, Arizona.
Cruziana trilobite feeding tracks, about 1.5 m long. Cambrian Tapeats Sandstone, Grand Canyon National Park, Arizona.
Basal conglomerate on the Great Unconformity between the Cambrian Tapeats Sandstone and underlying Proterozoic Basement rock. Grand Canyon National...
Great unconformity. Nonconformity between Cambrian Tapeats Sandstone overlying steeply foliated amphibolite of the Proterozoic Brahma Schist. Grand...
Great Unconformity between the Cambrian Tapeats Sandstone and underlying Proterozoic Basement rock. Grand Canyon National Park, Arizona.
Mississippian Baculite cephalopod ammonite in Redwall Limestone, Grand Canyon National Park, Arizona.
Chert nodules in Mississippian Redwall Limestone, possibly accumulations of sponge spicules, Grand Canyon National Park, Arizona.
Boardwalk pathway in Craters of the Moon National Monument and Preserve Idaho, Craters of the Moon is a national monument and wilderness preserve...
Entrance sign for Craters of the Moon National Monument and Preserve in southcentral Idaho, Craters of the Moon is a national monument and preserve...
Scenic view of Craters of the Moon National Monument and Preserve in Idaho, Craters of the Moon is a national monument and wilderness preserve...
Volcanic cinder cone fragments in Craters of the Moon National Monument and Preserve Idaho, Craters of the Moon is a national monument and wilderness...
