rockfall

(from the article `mass movement`) The types of mass movements caused by the above factors include: the abrupt movement and free fall of loosened blocks of solid rock, known as ...
Found on http://www.britannica.com/eb/a-z/r/59

Rockfall

Type of mass movement that involves the detachment and movement of a small block of rock from a cliff face to its base. Normally occurs when the rock has well defined bedding planes that are exaggerated by freeze-thaw action or thermal expansion and contraction.
Found on http://www.physicalgeography.net/physgeoglos/r.html

Rockfall

A rockfall or rock-fall refers to quantities of rock falling freely from a cliff face. A rockfall is a fragment of rock (a block) detached by sliding, toppling, or falling, that falls along a vertical or sub-vertical cliff, proceeds down slope by bouncing and flying along ballistic trajectories or by rolling on talus or debris slopes,” (Varnes, ...
Found on http://en.wikipedia.org/wiki/Rockfall

rockfall

The sudden fall of one or more large pieces of a rock from a cliff.
Found on https://www.encyclo.co.uk/local/22327

Rockfall

The most rapid type of mass movement, in which rocks ranging from large masses to small fragments are loosened from the face of a cliff.
Found on http://www.evcforum.net/WebPages/Glossary_Geology.html
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