Beaches and sand-bars developed well in the Shahejie Formation

Banqiao Depression.They are mainly high matured medium or fine grained sandbodies with good degree of sorting and good psephicity

platy-wedged shaped and parallel cross-bedding

formed in transgression or regression process.The beaches usually occur normal cyclic sequence and the bars are in reversal cyclic sequence.Their porosity and permeability are high

and lithophysical property is better than other sediments.So they are good oil and gas reservoirs.