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The tribology of cupules

Published online by Cambridge University Press:  05 March 2015

ROBERT G. BEDNARIK
ROBERT G. BEDNARIK*
Affiliation:
International Federation of Rock Art Organisations (IFRAO), PO Box 216, Caulfield South, Melbourne, VIC 3162, Australia
*
*E-mail: [email protected]
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Abstract

This paper describes a newly observed phenomenon, a rare form of lamina protecting petroglyphs from weathering, and it attempts an explanation of such features. These laminae are not precipitates but represent the floors of the original cupules that have become more resistant to erosion through conversion to tectonite. The process involves crystallization of the syntaxial quartz overgrowths on quartz grains that constitute the cement component of quartzite and silica-rich schist. It is attributed to the cumulative application of kinetic energy that derives from the tens of thousands of hammerstone blows that produced the cupule. The tribological process results in products similar to those formed in ductile shear zones when sandstone has been subjected to great kinetic stresses. In the cupules reported here, the re-metamorphosed lamina preserves their original surface and prevents the erosion of the protolith (parent rock) concealed by the modified layer. The thickness of the layer is a function of the cumulative amount of energy applied to the rock's cement, and the process of alteration is defined as ‘kinetic energy metamorphosis’.

Keywords

cupulemetamorphismtribochemistrykinetic energyquartzitesandstoneschist
Type
Rapid Communication
Information
Geological Magazine , Volume 152 , Issue 4 , July 2015 , pp. 758 - 765
Copyright
Copyright © Cambridge University Press 2015 

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References

Anderson, D. H. & Hawkes, H. E. 1958. Relative mobility of the common elements in weathering of some schist and granite areas. Geochimica et Cosmochimica Acta 14, 204–10.Google Scholar
Beaumont, P. B. & Bednarik, R. G. 2013. Tracing the emergence of palaeoart in sub-Saharan Africa. Rock Art Research 30, 33–54.Google Scholar
Beaumont, P. B. & Bednarik, R. G. In press. Concerning a cupule sequence on the edge of the Kalahari Desert in South Africa. Rock Art Research 32 (2).Google Scholar
Bednarik, R. G. 1993. Palaeolithic art in India. Man and Environment 18 (2), 33–40.Google Scholar
Bednarik, R. G. 1997. Microerosion analysis of petroglyphs in Valtellina, Italy. Origini 21, 7–22.Google Scholar
Bednarik, R. G. 2000. Age estimates for the petroglyph sequence of Inca Huasi, Mizque, Bolivia. Andean Past 6, 277–87.Google Scholar
Bednarik, R. G. 2007. Rock Art Science: The Scientific Study of Palaeoart, 2nd ed. New Delhi: Aryan Books International.Google Scholar
Bednarik, R. G. 2008. Cupules. Rock Art Research 25, 61–100.Google Scholar
Bednarik, R. G. 2010. A short ethnography of cupules. In Mysterious Cup Marks: Proceedings of the First International Cupule Conference (eds Lewis, R. Querejazu & Bednarik, R. G.), pp. 109–14. BAR International Series 2073, Oxford: Archaeopress.Google Scholar
Bednarik, R. G. & Khan, M. 2005. Scientific studies of Saudi Arabian rock art. Rock Art Research 22, 49–81.Google Scholar
Bednarik, R. G., Kumar, G., Watchman, A. & Roberts, R. G. 2005. Preliminary results of the EIP Project. Rock Art Research 22, 147–97.Google Scholar
Bhushan, B. 2013. Principles and Applications of Tribology, 2nd ed. New York: John Wiley and Sons.Google Scholar
Bowden, F. P. & Leben, L. 1939. The nature of sliding and the analysis of friction. Proceedings of the Royal Society of London A 169, 371–91.Google Scholar
Chigira, M. 1990. A mechanism of chemical weathering of mudstone in a mountainous area. Engineering Geology 29, 119–38.Google Scholar
Fahey, B. D. 1983. Frost action and hydration as rock weathering mechanisms on schist: a laboratory study. Earth Surface Processes and Landforms 8, 535–45.CrossRefGoogle Scholar
Francaviglia, V. M. 2005. Le copelle dell’area di El-Geili (Sudan). Rapporto preliminare. Sahara 16, 169–72.Google Scholar
Jost, P. 1966. Lubrication (Tribology): A Report on the Present Position an Industry's Needs. London: Department of Education and Science, Her Majesty's Stationery Office.Google Scholar
Kajdas, C. 2013. General approach to mechanochemistry and its relation to tribochemistry. In Tribology in Engineering (ed. Pihtili, H.). InTech. doi: 10.5772/50507.Google Scholar
Kumar, G. 1996. Daraki-Chattan: a Palaeolithic cupule site in India. Rock Art Research 13, 38–46.Google Scholar
Kumar, G. & Krishna, R. 2014. Understanding the technology of the Daraki-Chattan cupules: the cupule replication project. Rock Art Research 31, 177–86.Google Scholar
Macaulay, C. 2003. Low Temperature Quartz Cementation of the Upper Cretaceous White Sandstone of Lochaline, Argyll, Scotland. University of Edinburgh Micro-analysis Unit, 4 pp.Google Scholar
McBride, E. F. 1989. Quartz cement in sandstones: a review. Earth-Science Reviews 26, 69–112.Google Scholar
Murakami, T., Isobe, H., Sato, T. & Ohnuki, T. 1996. Weathering of chlorite in a quartz-chlorite schist: I. mineralogical and chemical changes. Clays and Clay Minerals 44, 244–56.Google Scholar
Pereira, J. P. & de Freitas, M. H. 1993. Mechanisms of shear failure in artificial fractures of sandstone and their implication for models of hydromechanical coupling. Rock Mechanics and Rock Engineering 26, 195–214.CrossRefGoogle Scholar
Repas, R. 2008. Sensor sense: piezoelectric force sensors. Some materials generate an electric charge when placed under mechanical stress. Machinedesign.com, http://machinedesign.com/sensors/sensor-sense-piezoelectric-force-sensors [Date last accessed: 11 December 2013].Google Scholar
Wells, T., Binning, P. & Willgoose, G. 2005. The role of moisture cycling in the weathering of a quartz chlorite schist in a tropical environment: findings of a laboratory simulation. Earth Surface Processes and Landforms 30, 413–28.CrossRefGoogle Scholar
Wells, T., Binning, P., Willgoose, G. & Hancock, G. 2006. Laboratory simulation of the salt weathering of schist: I. weathering of schist blocks in a seasonally wet tropical environment. Earth Surface Processes and Landforms 31, 339–54.Google Scholar
Zauyah, S. & Stoops, G. 1990. A study of the ferralitic weathering of an amphibole schist in peninsular Malaysia. Pertanika 13, 85–93.Google Scholar