Source identification using heavy minerals for small floodplain lakes: a case study of Dongping Lake, North China

Abstract

Heavy minerals offer significant potential in elucidating sediment provenance in a variety of depositional systems. Nevertheless, source identification through heavy minerals remains a relatively understudied aspect, particularly for small floodplain lakes. Located in the North China Plain, Dongping Lake represents an exceptional site for validating the efficacy of this methodology. In this study, we collected 31 samples from Dongping Lake and surrounding floodplains and used analyses of heavy mineral compositions to establish the spatial distribution and characteristics of source regions and modern sediments of Dongping Lake. The heavy mineral assemblages demonstrate significant variations for sediments of the Yellow River and the Dawen River. The Yellow River floodplain samples are dominated by hornblende, epidote, limonite, and actinolite, with minor garnet, sphene, clinozoisite, etc. Samples from the Dawen River are dominated by epidote, hornblende, and actinolite, with minor sphene, clinozoisite, limonite, apatite, etc. Our data show that modern sediments of Dongping Lake exhibit significant variations in heavy mineral assemblages. The mineralogical composition at most sites except for the southeastern part of Dongping Lake is similar to that of sediments in the Yellow River, but differs markedly from that in the Dawen River. This variation indicates that the Yellow River contributes significant volumes of sediment to modern sediments of Dongping Lake. The results are also confirmed by the grain-size end-member unmixing analysis in modern sediments of the lake. Specifically, materials derived from the Yellow River exhibit a widespread dispersion across the lake, whilst those originated from the Dawen River are primarily concentrated in the river mouth. In addition, proximally eroded materials from the west shore of the lake also have some extent of influence, but are mainly distributed in the western region of the lake.