"Plotting of shape functions of clastic particles against size provides strong evidence that most natural sandy and pebbly deposits (particles longer than 0.1 mm) are deposited as composites, whereas they are often assumed in granulometric analysis to represent single homogeneous particle populations. Basic data used were p, q, and r, approximately equivalent to particle length, breadth, and depth respectively. Plots of the elongation function (p/q) against p indicate that samples of water-laid sandy and pebbly deposits taken from single sedimentary laminae consist of natural mixtures of up to three distinct particle populations and that these, named A, B, and C, combine to make four sediment types composed of A, AB, ABC, and AC. Three-dimensional studies of the particles forming these sediments strongly support this interpretation."