The Jianchuan Basin is a key region for determining the spatial-temporal evolution of paleodrainage and tectonic at the southeastern Tibetan Plateau. New detrital zircon U-Pb geochronology and paleocurrent data from Eocene formations in this basin suggest that the sediment sources switched from the remote sources (including Hoh-Xil, Songpan-Ganzi, North Qiangtang, Yidun and western Yangtze terranes) to local lithologies (adjacent Triassic and Eocene igneous rocks and western Yangtze block) from the early-middle Eocene Baoxiangsi to the late Eocene Shuanghe and Jianchuan Formations. Such provenance changes support that large-scale drainage reorganization occurred in the late Eocene (prior to ~36 Ma). This significant late Eocene provenance and drainage changes occurred as one of the responses to coeval topographic uplift in the southeastern Tibetan Plateau.

中文翻译：

---

青藏高原东南部剑川盆地碎屑锆石U-Pb年代学及其对构造古排水演化的意义

剑川盆地是确定青藏高原东南部古排水和构造时空演化的关键区域。该盆地始新世地层新碎屑锆石 U-Pb 年代学和古洋流资料表明，沉积物来源由偏远源（包括可可西里、松潘-甘孜、北羌塘、义墩和扬子地体西部）转变为局部岩性（邻近三叠系和始新世火成岩和扬子地块西部）早中始新世宝相寺至晚始新世双河组和剑川组。这种物源变化支持大规模的水系重组发生在始新世晚期（~36 Ma 之前）。