银川盆地晚上新世物质来源及其对黄河上游形成年代的约束

黄河上游河段的形成年代依然存在争论，而银川盆地是黄河上游物质的主要沉积区之一，该盆地沉积序列的研究能为了解黄河上游的物质来源和形成年代提供重要线索。对银川盆地钻孔（PL02）底部进行了碎屑锆石U-Pb测年和碎屑组分统计研究，并与上游黄河沉积物以及盆地周边贺兰山和鄂尔多斯高原西部的锆石U-Pb年龄数据和碎屑组分数据进行了对比分析。结果表明贺兰山和鄂尔多斯高原西部并不是银川盆地晚上新世沉积物的物质供应区，而是黄河将银川盆地以上河段地区物质输送到银川盆地。这一结果进一步证明了黄河上游兰州—银川段在晚上新世已经形成的观点。

Late Pliocene Sedimentary Provenance of the Yinchuan Basin and Its Constraints on the Formation Age of the Upper Yellow River

The formation age of the upper reaches of the Yellow River is still debated. The Yinchuan Basin is one of the main sedimentary areas in the upper reaches of the Yellow River， and its sedimentary sequence provides important clues to an understanding of the material source and formation age of the upper Yellow River. In this study， detrital zircon U-Pb age geochronological and petrographic composition data were determined for Late Pliocene sediments from the bottom of drill core PL02 in the Yinchuan Basin. This information was compared with other data for potential sources. The results show that the Helan Mountain and the western Ordos Plateau were not the source areas of Late Pliocene sediments in the Yinchuan Basin. Rather， the Yellow River transported material from the upper-reach areas to the Yinchuan Basin. This result further supports the view that the Lanzhou-to-Yinchuan portion of the upper Yellow River was formed in the Late Pliocene.