The Hawkesbury Sandstone south of Sydney, Australia: Triassic analogue for the deposit of a large, braided river.

Unidirectional paleoflow in the sandstone, its freshwater biota, and abundant mudrock intraclasts indicate fluvial deposition. Sheet morphology, low paleocurrent variance, abundant erosion surfaces, and the paucity of in situ mudrocks point to a braided fluvial system. Three facies assemblages have been recognized: stratified sandstone, massive sandstone, and a minor mudrock assemblage. The Sandstone does not conform to existing models for braided-fluvial deposition in that planar cross-strata accumulated in deeper parts of channels, whereas trough cross-strata formed in shallower water. The Hawkesbury River was very large, with deep main channels and high but variable discharge. -from Authors