Upstream-dipping foreset cross-stratification; origin and implications for paleoslope analyses

ABSTRACT Fluviatile cross-stratification dipping up paleoslope is not always backset cross-stratification. Investigations on the Barwon River, N.S.W., Australia show that upstream-dipping foreset cross-stratification of a type intermediate between Allen's Eta and Theta types can form on point bars due to flow separation at sharp bends, with consequent reverse (upstream) current flow. This cross-stratified sand gave an elongation function curve characteristic of the lower flow regime.