This section presents the substance of what the major kinds of cross stratification in the sedimentary record look like. They conveniently fall into (1) unidirectional-flow cross stratification, on a ...This section presents the substance of what the major kinds of cross stratification in the sedimentary record look like. They conveniently fall into (1) unidirectional-flow cross stratification, on a small scale corresponding to ripples and on a larger scale corresponding to dunes, and (2) oscillatory-flow cross stratification. Unfortunately there is little I can say at present about combined-flow cross stratification.