四川盆地东北部上三叠统须家河组四段物源分析

四川盆地东北部地区上三叠统须家河组须四段是油气勘探的重点层段，该地区的沉积受到多物源的影响.通过对研究区重矿物、碎屑组分、岩屑成分和古水流方向的分析，最终确定了研究区须四段的物源来自龙门山、大巴山和米仓山3个方向.其中，元坝西部地区物源来自于龙门山褶皱带方向；元坝东部地区物源来自大巴山褶皱带东南部方向；元坝中部部分地区表现为龙门山和大巴山的混合堆积；通南巴西部地区物源来自米仓山褶皱带方向，通南巴东部物源表现为大巴山和米仓山的混合堆积.

PROVENANCE ANALYSIS ON THE FOURTH MEMBER OF XUJIAHE FORMATION,UPPER TRIASSIC IN THE NORTHEASTERN SICHUAN BASIN

The 4th Member of Xujiahe Formation, Upper Triassic, in the northeastern Sichuan Basin is a key layer for oil-gas exploration. The deposition in the area is affected by multiple provenances. By analyzing the heavy minerals, clastic constituents, debris compositions and paleocurrent directions, it is finally determined that the provenances originate from three directions, namely, Longmenshan, Dabashan and Micangshan. The provenance of the western Yuanba is from Longmenshan fold belt; that of the eastern Yuanba, from the southeast of Dabashan fold belt; that of the central Yuanba, from the mixed accumulation of Longmenshan and Dabashan; that of the western Tongnanba area, from the Micangshan fold belt; while that of the eastern Tongnanba area, from the mixed accumulation of Dabashan and Micangshan.