The shapes of beach pebbles

Professional Paper 131-C



There is much confusion in geologic literature as to the shapes of fluvial and beach pebbles and the differences between them, if differences exist. Though the contrary has been asserted, most geologists who have written on the subject appear to hold the view that beach pebbles are generally flatter than river pebbles, having discoid, lozenge-shaped, ellipsoid, or oval forms. It is asserted by some that these forms are produced by pushing of the rock fragments to and fro by the waves. Others have considered that the shapes of the original fragments and the inherent structure of the rock are dominant in determining the shapes of beach pebbles, and with this view the writer is in accord. That beach pebbles, even those composed of massive igneous rocks are commonly of a flattened oval form seems certain, as has been stated elsewhere, but this fact is probably to be attributed to the development of such forms from original flat fragments or from rocks of schistose structure or to the segregation of such forms under the peculiar action of the waves, rather than to their production by a specialized wave abrasion.

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title The shapes of beach pebbles
Series title Professional Paper
Series number 131
Chapter C
DOI 10.3133/pp131C
Year Published 1923
Language English
Description 11 p.
First page 75
Last page 83
Country United States
State Connecticut;Massachusetts
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