Precarious boulder

Precarious boulder

Precarious boulder refers to a large rock or boulder resting either on the ground or on another rock in an apparently unstable position. This can arise by a few mechanisms:
*Erosion may have removed the basal rock or sediment, leaving the boulder exposed
* The rock may have been transported from an ice sheet and was left exposed when the ice retreated—this is more accurately called a glacial erratic
*The rock may have been transported and placed at the location from a catastrophic geologic process, such as:
** Through a rockfall
** From a volcanic eruption, which results in lava bombs
** From a cataclysmic flood, such as a glacial lake outburst flood

ee also

*Glacial erratic
*Hoodoo (geology)


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