Tag Archive for: geology
Island in the Sky District, Canyonlands National Park, San Juan County, Utah
Photographer: Taylor Boden
The La Sal Mountains laccolith (a shallow, mushroom-shaped igneous intrusion) of Oligocene age rises above the red Mesozoic and Paleozoic sedimentary rocks exposed in the Colorado River drainage. Washer Woman Arch, visible in the upper part of the small butte in the middle foreground, is eroded out of the Triassic-Jurassic-aged Wingate Sandstone.
Island in the Sky District, Canyonlands National Park, San Juan County, Utah
Photographer: Mike Hylland
Desert primrose blooms in thin, gravelly soil along the White Rim Trail. The Permian-aged White Rim Sandstone forms a broad, nearly flat bench above the adjacent Green and Colorado Rivers and below towering cliffs (visible in the distance) of the Triassic-Jurassic-aged Wingate Sandstone and thin cap of Jurassic Kayenta Formation. In the middle distance, Candlestick Tower consists of Kayenta Formation and Wingate Sandstone above sloping Chinle Formation (Triassic) on a base of Moenkopi Formation (Triassic), which overlies the White Rim Sandstone. The gentle tilt of the strata reflects their location on the southwestern flank of the broad downwarp of the Grays Pasture syncline.
Slickrock Trail near Moab, Grand County, Utah
Photographer: Jim Davis
Giant weathering pits or potholes like this one (about 16 feet across at the bottom) in the Jurassic-age Navajo Sandstone typically form along fractures and joints atop fins, knolls, and rounded domes. Potholes are created through a combination of physical, chemical, and biological processes that weather and erode the rock and are home to a remarkable array of ancient aquatic organisms.