Deposits consist predominantly of beach conglomerate and features of the beachface depositional environment prevail. The upper sequence forms an onlap across the middle sequence, and represents a second transgressive unit. Theoretical evidence exists that a regressive erosional hiatus separated the two transgressive events. The upper sequence consists of tidal channel sandstone, accumulated in palaeoestuaries. Although dominated by sandstone, this upper sequence contains subordinate rudite and shale components.
Tidal features occur in palaeochannel deposits that display well-defined meander structures.
Depositional conditions varied within the palaeoestuaries, providing a range of habitats for burrowing organisms, and a variety of outstanding trace fossils is exposed in the upper sequence. Body fossils are poorly represented. Unusual depositional events interrupted the normal tidal sedimentary processes within the palaeoestuaries. These events included river floods, barrier overwash episodes and cataclysmic events, such as tsunamis or perhaps storm surges. Crustal movement in the tectonically active basin rather than eustatic change in sea level led to the changes in relative sea level that produced the transgressions and the intervening regression.