ABSTRACT

Two well exposed outcrops of the Homewood Sandstone in western Pennsylvania provide an excellent opportunity to document and compare local dip azimuth variability of tabular and trough types of cross-bedding. Tabular-shaped cross-beds occur at one locality; trough-shaped units at the other.

All measures of scatter--consistency ratio, standard deviation, and spread--are appreciably greater for the randomly measured foreset dip azimuths of trough cross-bedding. If readings along trough axes only are considered, the scatter is greatly reduced and is comparable to that displayed by tabular cross-bedding foresets. At each locality the current direction is uniform both stratigraphically and areally. Thus, the markedly different distributions of foreset azimuths for these two cross-bedding types is related to an inherent property of the sedimentary structure, the curvature of foresets within individual units.