GEOLOGY

Detailed explanation-1: -Most people understand that erosion plays an important role in creating arches and bridges. There are two types of erosive forces that account for most arches and bridges – weather erosion and water erosion. If a crack forms in the soft layers of a sandstone fin, it allows wind to penetrate into the rock.

Detailed explanation-2: -In winter, snowmelt pools in fractures and other cavities, then freezes and expands, breaking off chunks of sandstone. Small recesses develop and grow bigger with each storm. Little by little, this process turns fractured rock layers into fins, and fins into arches.

Detailed explanation-3: -The softer rock stratum erodes away creating rock shelters, or alcoves, on opposite sides of the formation beneath the relatively harder stratum, or caprock, above it. The alcoves erode further into the formation eventually meeting underneath the harder caprock layer, thus creating an arch.

Detailed explanation-4: -Arches are naturally occurring rock formations shaped like an upside-down letter U and are usually a result of mechanical weathering. An example of chemical weathering is carbonic acid, a compound of carbon dioxide and water that can dissolve limestone, leaving formations of columns, caves, and sinkholes called karst.