Sedimentary characteristics of the Triassic braided river delta in Tarim Basin Platform

Braided river delta is an important reservoir type and hydrocarbon exploration target in continental sedimentary basins.Using core,log,and seismic data,this paper indicates that the braided river delta in the Triassic of platform area in Tarim Basin was deposited extensively in the shore-shallow lake background.The platform is generally in the sedimentary environments with in a gentle slope and shallow water.Sand bodies of braided river delta extended continuously from the periphery to the center of the basin.Progradational braided river delta was deposited which has the typical characteristics of arenaceous-conglomeritic sediments,large cross bedding,coarse intermittent positive rhythm,as well as typical incised valley or progradational seismic reflectance signatures.And sand bodies of underwater distributary channel are the backbone ones.The characteristics of sedimentary subfacies and microfacies are also discussed in the paper.At last,favorable lithologic and stratigraphic traps in the platform area are divided and evaluated.