Boulder
Get Boulder essential facts below. View Videos or join the Boulder discussion. Add Boulder to your PopFlock.com topic list for future reference or share this resource on social media.
Boulder
This balancing boulder, "Balanced Rock" stands in Garden of the Gods park in Colorado Springs, Colorado, United States.
Boulder in British Columbia, Canada
Boulder in a bay in Bic National Park, Québec
Kämmenkivi stone on the Pisa hill in Kuopio, Finland
Devonian conglomerate in Scotland with clasts up to boulder in size

In geology, a boulder is a rock fragment with size greater than 256 millimetres (10.1 in) in diameter.[1] Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive.[2] In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called rocks (American English) or stones (In British English a rock is larger than a boulder).[disputed ] The word boulder is short for boulder stone, from Middle English bulderston or Swedish bullersten.[3]

In places covered by ice sheets during Ice Ages, such as Scandinavia, northern North America, and Siberia, glacial erratics are common. Erratics are boulders picked up by ice sheets during their advance, and deposited when they melt.[2] They are called "erratic" because they typically are of a different rock type than the bedrock on which they are deposited. One of them is used as the pedestal of the Bronze Horseman in Saint Petersburg, Russia.

Some noted rock formations involve giant boulders exposed by erosion, such as the Devil's Marbles in Australia's Northern Territory, the Horeke basalts in New Zealand, where an entire valley contains only boulders, and The Baths on the island of Virgin Gorda in the British Virgin Islands.

Boulder-sized clasts are found in some sedimentary rocks, such as coarse conglomerate and boulder clay.

The climbing of large boulders is called bouldering.

See also

References

  1. ^ Neuendorf, K.K.E.; Mehl, Jr., J.P.; Jackson, J.A. (editors) (2005). Glossary of Geology (5th ed.). Alexandria, Virginia: American Geological Institute. p. 79. ISBN 978-0922152896.CS1 maint: extra text: authors list (link)
  2. ^ a b "Boulder". Dictionary.com. Retrieved 2013.
  3. ^ boulder. (n.d.) Online Etymology Dictionary. Retrieved December 9, 2011, from Dictionary.com website.

External links

Media related to Boulders at Wikimedia Commons


  This article uses material from the Wikipedia page available here. It is released under the Creative Commons Attribution-Share-Alike License 3.0.

Boulder
 



 



 
Music Scenes