Resistance (geology)

Geological resistance is a measure of how well minerals resist erosive factors, and is primarily based on hardness, chemical reactivity and cohesion.[1] The more hardness, less reactivity and more cohesion a mineral has, the less susceptible it will be to erosion. Differences in geological resistance in the same geological formation can lead, over time, to the formation of columns and arches like the ones in Moab, Utah and bridges like the Rainbow Bridge, also in Utah.

...
Wikipedia