Clast Analysis Assumptions/ Resources
Some things that may or may not help and in no particular order:
- Be sure you understand the transport model of Menzies, 1995, fig 8.14. and the results of roundness/ shpericity measurements on alpine glaicer
- What does a plot of Sphercity vs. Roundness show?
- Sneed and Folk, 1958 suggest that sphericity (S) can be calculated from:
- S = (cube root of C axis squared) / A axis x B axis.
- Consider the effect of total transport distance on roundness. Figure 8.13 from Drewery helps. Be careful how you use this graph. The % contours are the amount of a given rock type remaining for each roundness value. Thus at 5 km less that 0.1 % of the clasts remaining have roundness of .1, but 0.5 % have roundness values of .3.
- Does this plot help? After Koster and others, 1980, Can J. Earth Sci., p. 1725-1739. Use with caution, this based on boulders not pebbles.
- A reference to rock shape: Barrett, P.J., 1980, The Shape of rock particles, a critical review, Sedimentology, 27, p. 291-303. Probably more than you would ever care about.
- Perhaps consider the techniques suggested in - Benn and Ballantyne, 1994, Reconstructing the transport history of glacigenic sediments: A new approach based on the co-variance of clasts form indices, Sedimentary Geology, v. 91, p. 215-227.
- One more critical resource.
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Erosion and Transport
