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Bedrock mortar

BRM in a rock shelter on the Upper Cumberland Plateau.

A bedrock mortar (BRM) is an anthropogenic circular depression in a rock outcrop or naturally occurring slab, used by people in the past for grinding of grain, acorns or other food products.[1] There are often a cluster of a considerable number of such holes in proximity indicating that people gathered in groups to conduct food grinding in prehistoric cultures. Correspondingly the alternative name gossip stone is sometimes applied, indicating the social context of the food grinding activity. Typical dimensions of the circular indentations are approximately 12 centimeters in diameter by 10 centimeters deep, although a considerable range of depths of the cavities have been documented .[2] The bedrock mortar has been identified in a number of world regions, but has been particularly intensely documented in the Americas. An alternative term for the bedrock mortar site is bedrock milling station.


Bedrock metateEdit

A bedrock mortar should not be confused with a bedrock metate, which is a flat, trough-shaped depression often found with bedrock mortars.[3]

Example locations of occurrenceEdit


See alsoEdit

Line note referencesEdit

  1. ^ Archaeology online glossary
  2. ^ Discovering Prehistoric Sites: Objective and Subjective Survey Techniques, Daniel G. Foster, Brian D. Dillon, and Linda C. Sandelin, California Department of Forestry and Fire Protection, June 13, 2005
  3. ^ "Cultural Resources of the Santa Rita Experimental Range" (PDF). John H. Madsen. Retrieved 4 December 2013.
  4. ^ G. Deghi, J. Buxton et al., Earth Metrics, Environmental Impact Report for the Saxon Creek Water Project, Mariposa County, California, published by the County of Mariposa Planning Department and Mariposa County Water Agency, Report 10298, May, 1990
  5. ^
  6. ^ "C. Melvin Aikens, Cultural Continuity in the Sierra Tarahumara of Southern Chihuahua, Mexico, June 2003". Archived from the original on 2007-05-27. Retrieved 2007-07-02.
  7. ^ M. Del Pilar Babot, María C. Apella, Maize and Bone: Residues of Grinding in Northwestern Argentina, Archaeometry, Volume 45 Issue 1 Page 121-132, February 2003