Sandstone fins
Arches National Park
Most of the formations at Arches are made of soft red sandstone deposited 150 million years ago. Much later, groundwater began to dissolve the underlying salt deposits. The sandstone domes collapsed and weathered into a maze of vertical rock slabs called "fins." Sections of these slender walls eventually wore through, creating the spectacular rock sculptures that visitors to Arches see today. Source: travel.nationalgeographic.com/travel/national-parks/arche...
Sandstone fins
Arches National Park
Most of the formations at Arches are made of soft red sandstone deposited 150 million years ago. Much later, groundwater began to dissolve the underlying salt deposits. The sandstone domes collapsed and weathered into a maze of vertical rock slabs called "fins." Sections of these slender walls eventually wore through, creating the spectacular rock sculptures that visitors to Arches see today. Source: travel.nationalgeographic.com/travel/national-parks/arche...