Erosional and Depositional Features

Volcanic necks are the remnants of a volcano’s conduit and plumbing system that remain after most of the rest of the volcano has been eroded away.

Inverted topography arises when lava flows that filled valleys at the time of their eruption later hold up mesas because their resistance to erosion is greater than most other rock types.

A bouquet of tiny arches? A miniature cave system? Known as honeycomb weathering or "swiss-cheese rock," tafoni (singular: tafone) are small, rounded, smooth-edged openings in a rock surface, most often found in arid or semi-arid deserts.

Arches National Park has the densest concentration of natural stone arches in the world. There are over 2,000 documented arches in the park, plus pinnacles, balanced rocks, fins and other geologic formations. Some are more notable than others. Here is a sampling of some of the longest, tallest, and most famous rock formations in the park.

Desert sand dunes interact strongly with external drivers, including wind, vegetation, and groundwater. Given the ubiquity of sand dunes on Earth’s deserts and on extraterrestrial environments, this research attempts to understand how dune fields respond to these complex external forces.

In the southeast corner of Canyonlands, spires of Cedar Mesa Sandstone rise hundreds of feet above a network of canyons and grasslands know as "The Needles."

Every arch in the park is as unique as a fingerprint, telling its own personal story of rock, water, time and change. When discussing them scientifically, however, it's helpful to group them into categories by their shape or apparent mechanism of formation.

Park staff and scientists study geological change in the natural arches of Utah. Monitoring devices, like the crackmeter, measure vibration and expansion in arches that are actively eroding. The data collected could determine potential safety risks in the future.