On the composition of rare earth elements of suspended substance in lower reach of the Yangtze River and main rivers in Zhejiang Province in dry season

Sixty-four samples of suspended substance were collected in October–November, 2021 from the lower reaches of Yangtze River and major rivers in Zhejiang Province in dry season, from which the differences of distribution characteristics of rare earth elements (REEs) and provenance indication of the suspended substance were discussed. Results show that the average REE contents in the suspended substance from the lower reaches of the Yangtze River, Qiantang River, Jiaojiang River, and Oujiang River in dry season were about 209.52, 173.64, 211.86, and 228.70 mg/kg, respectively, and the contents of REEs of the Qiantang River and the Oujiang River were obviously higher than previous data. The normalized partition curve against the value of North American Shale Composition (NASC) was gentle in general and slightly incline to the right, with obvious MREE enrichment, which is consistent in overall with the previous studies of the Yangtze River and major rivers in Zhejiang Province. The diagrams of (La/Yb)_NASC vs (La/G)_NASC, the index of (La/Yb)_NASC, and (La/Gd)_NASC were used to distinguish provenance of the Yangtze River from rivers in Zhejiang Province. The distribution scope of (La/Yb)_NASC and (La/Gd)_NASC of suspended substance of this study is more concentrated than those of the historical data, which mean that suspended substance could be used for river provenance study.