ARCH TYPES PRESENT IN EROSIONAL FEATURES: A STUDY OF ARCHES NATIONAL PARK

Arches National Park is widely known for having over 2,000 natural arch features present within the boundaries of the park, and there have been many attempts over the years to answer why so many arches exist in this small geographic area. This study evaluates a sample of 297 arches present within the park, with spans of over ten feet (considered geologically significant), categorizes them to different erosional areas of the park, and assigns a taxonomic classification based on the method of weathering. Previous attempts to taxonomically classify arches have been based on how the arch presently appears, rather than how it geologically came to be. This study re-defines arch classifications and interprets correlations of arch types with erosional structures such as canyons, fins, and domes within geographic areas of Arches National Park. Arches were evaluated with data available on the World Arch Database, with several requiring inspection in person to ensure proper interpretation. The majority of arches in the dataset (45%) were classified as alcove arches and found to occur in fins and canyons with excessive jointing and areas prone to freeze-thaw weathering, with pothole and surface bridge types occurring primarily in domed sandstone features; fin types were found to be prevalent throughout the entire park. This research provides insight into how and why certain arch types are present in sandstone-based erosional landscapes, allowing for a better understanding of the present erosional processes seen in the geomorphological features of Arches National Park and could be applied to other geologically similar areas.