PROVENANCE STUDY OF YELLOW RIVER SEDIMENTS BY U-Pb DATING OF THE DETRITAL ZIRCONS

Six major U-Pb age groups of detrital zircons are recognized in the modern Yellow River sediments. They are 200~350 Ma、350~500 Ma、700~1 000 Ma、1 000~1 800 Ma、1 800~2 000 Ma and 2 000~2 600 Ma respectively with 200~350 Ma、350~500 Ma、1 800~2 000 Ma and 2 000~2 600 Ma dominating. By comparison of the U-Pb age patterns with the potential source areas of the Yellow River drainage basin, it is deduced that the upper reach sediments of the Yellow River are mainly derived from the Songpan-Ganzi block and the loess nearby transported by rivers. These clastic sediments might come from the North China Carton, the Yangtze Carton, the Qinling orogen, the East-Kunlun Orogenic Belt, the Qilian Terrane and the northern margin of the Qaidam basin. The deposits from the middle and lower Yellow River, however, show significant contribution from the North China Carton and the Sulu orogen. Learnt from the great progress achieved based on integrated provenance study of the Changjiang River delta by deep holes, we suggest similar approach being taken for high-resolution provenance analysis of the Yellow River Delta so as to reveal the spatio-temperal evolution of the river.