Cross-bedding occurs anytime a new depositional units is inclined to the previous depositional surface. Two types of cross-beds can form: trough and planar. Cross-beds are formed by both water and wind action. The steeper foreset beds are usually less than 30 degrees. The inclination of the beds is controlled by the rate of deposition, and the amount and coarseness of the material. Fast deposition of coarser material in large volumes creates steeper bedding. Cross-beds are common in scour-and-fill features where stream erosion creates a channel for the crossbed deposition. Truncation and unconformities (discontinuities between beds) are common.
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Development of cross beds Burchfield, B. Clark; Foster, Robert; Keller, Edward; Melhorn, Wilton; Brookins, Douglas; Mintz, Leigh; Thurman, Harold.
Physical Geology.
Charles E. Merrill Publishing Co., 1982.
