中文摘要：

运用砂岩碎屑组分、古水流、微量和稀土元素方法对西藏南部仁布地区上三叠统朗杰学群和涅如组的物源进行了分析。碎屑组分和地球化学研究结果显示,盆地中的碎屑物源主要来自再旋回造山带,部分来自造山之前的混合区,少数源于大陆基底,且物源区蕴含有造山前的大陆边缘岛弧过程;物源区母岩主要为沉积再旋回和后太古代再旋回沉积物;古水流测量分析表明,朗杰学群和涅如组的物源可能均来自北边,但前者物源偏于东北方向,后者物源偏于西北方向,且前者较后者离物源区相对较近,符合现今二者地层的分布特征。这些认识为研究区上三叠统复理石可能来自北部甚至拉萨地块的观点提供了新的支持。

英文摘要：

The sandstone clastic composition,paleocurrent,trace element and rare earth clement are combined to analyze the provenance of the Upper Triassic Langjiexue Group and the Nieru Formation in Renbu area,southern Tibet.Results of the clastic composition and geochemistry indicate that most of the clastic materials were derived from the recycled orogenic belt;Some of them were from the mixed area before the orogeny;Few was from the continental basement and recorded continental margin arc process prior to the orogeny.It is verified that parent rocks came from the recycled sediments of the orogen and post-Archean.Paleocurrent measurement shows that the Langjiexue Group and the Nieru Formation were probably sourced from the North.The former was from the northeast,but the latter was from the northwest.The latter is closer to the source region than the former.These are consistent with the present distribution of strata.These results suggest that the upper Triassic flysch were probably sourced from the north or even the Lhasa Block.