Hostname: page-component-5c6d5d7d68-txr5j Total loading time: 0 Render date: 2024-08-15T05:09:24.318Z Has data issue: false hasContentIssue false

Particle rounding in beach gravels

Published online by Cambridge University Press:  01 May 2009

Brian J. Bluck
Affiliation:
Department of Geology, The University, Glasgow, W. 2.

Summary

Splitting, crushing and spalling which occur when boulders move against each other, generate fine material and so give rise to angular large and small sizes. The nature of the rounding process can be deduced from the analysis of moments of the roundness frequency distribution of the size range 4–128 mm. A low standard deviation indicates the dominance of one process—either abrasion or breakdown; a high standard deviation indicates the presence of both. The relationship between mean roundness, standard deviation of roundness, skewness of roundness and mean size allows for an analysis of the size reduction processes at work on the sediment; and for a comparison between the reactions of different rocks. A model, based on actual data, is given for the evolution of roundness of limestone clasts on a beach.

Type
Articles
Copyright
Copyright © Cambridge University Press 1969

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Bartrum, J. A., 1947. The rate of rounding of beach boulders. J. Geol., 55, 514–5.CrossRefGoogle Scholar
Bluck, B. J., 1967. Sedimentation of beach gravels: examples from South Wales. J. sedim. Petrol., 37, 128156.Google Scholar
Bretz, J. H., 1929. Valley deposits immediately east of channelled scabland of Washington II. J. Geol., 37, 505541.CrossRefGoogle Scholar
Grogan, R. M., 1945. Shape variation of some Lake Superior beach pebbles. J. sedim. Petrol., 15, 310.CrossRefGoogle Scholar
Krumbein, W. C., 1941. Measurement and geological significance of shape and roundness of sedimentary particles. J. sedim. Petrol., 11, 6472.CrossRefGoogle Scholar
Kuenen, Ph. H., 1956. Experimental abrasion of pebbles 2. Rolling by currents. J. Geol., 64, 336368.CrossRefGoogle Scholar
Landon, R. E., 1930. An analysis of beach pebble abrasion and transportation. J. Geol., 38, 437446.CrossRefGoogle Scholar
Moss, A. J., 1963. The physical nature of common sandy and pebbly deposits. Part II. Am. J. Sei., 261, 297343.Google Scholar
Pettijohn, F. J., 1957. Sedimentary rocks. 2nd. Edit. Harper and Brothers, New York.Google Scholar
Sneed, E. D., & Folk, R. L., 1958. Pebbles in the Lower Colorado River, Texas. A study in particle morphogenesis. J. Geol., 66, 114150.CrossRefGoogle Scholar
Wentworth, C. K., 1922a. A field study of the shapes of river pebbles. Bull. U.S. geol. Surv., 730, 103114.Google Scholar
Wentworth, C. K., 1922b. The shapes of beach pebbles. U.S. geol. Surv. Prof. Pap., 131–C, 7583.Google Scholar