Boulder

In geology, a boulder (or rarely bowlder)^[1] is a rock fragment with size greater than 25.6 cm (10.1 in) in diameter.^[2] Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive.^[3] In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called rocks or stones.

^ Webster’s New International Dictionary of the English Language. Springfield, Massachusetts: G. & C. Merriam Company. 1913.
^ Neuendorf, K.K.E.; Mehl, J.P. Jr.; Jackson, J.A., eds. (2005). Glossary of Geology (5th ed.). Alexandria, Virginia: American Geological Institute. p. 79. ISBN 978-0922152896.
^ "Boulder". Dictionary.com. Retrieved 24 August 2013.

[1] Webster’s New International Dictionary of the English Language. Springfield, Massachusetts: G. & C. Merriam Company. 1913.

[Glossary2005-2] Neuendorf, K.K.E.; Mehl, J.P. Jr.; Jackson, J.A., eds. (2005). Glossary of Geology (5th ed.). Alexandria, Virginia: American Geological Institute. p. 79. ISBN 978-0922152896.

[Boulder-3] "Boulder". Dictionary.com. Retrieved 24 August 2013.

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