Sediment samples collected in blowouts were analyzed.Results indicate that particle size and sorting parameters vary systematically with blowout position.Sediment in a trough blowout is mainly composed of medium and fine sand

with less coarse sand and silt.No gravel is observed in the trough blowout.Because of relatively uniform composition of sediment particles

frequency curve varying with different depths of the trough blowout show the single peak symmetry.In response to wind erosion and accumulation

the contents of coarse sand and fine sand

the plural size for frequency curve

and the average particle size change significantly.The results testify the flow models of blowout.