Clay mineral assemblages and provenance in the surface sediment of Jiaozhou Bay

The content and composition of clay minerals from 150 surface sediment samples obtained in 2019 from the Jiaozhou Bay, Qingdao, East China were analyzed using XRD. The distribution characteristics and sediments resources were discussed. Results show that illite (65.1%) dominated in the surface sediments, smectite (17.1%) ranked the second, followed by chlorite (9.0%) and kaolinite (8.8%). On the spatial scale, the illite contents were higher in the west and lower in the east, and the higher value areas were mainly distributed near the mouths of Dagu River and Yanghe River. Smectite contents were higher in the northeast; chlorite contents were higher in the east and lower in the west area, and the higher area of chlorite showed a zonal distribution. The higher distribution of kaolinite was patchy and the regularity was not obvious. Provenance analysis showed that terrestrial materials carried by inflow rivers were the main material sources, including Dagu, Yanghe, and Nanjiaolai Rivers. Besides, the Dagu River was the main provenance of illite, smectite and kaolinite, while chlorite was jointly from the Dagu River borne materials and the erosion product of coastal materials.