The provenance of radial sand ridges off the Jiangsu coast, East China: Constraints from the heavy mineral compositions and zircon geochronology

Abstract

The radial sand ridges (RSRs) off the Jiangsu coastal zone, East China, is a large special sedimentary landform formed by land-ocean interactions. Its sedimentary provenance is a scientific issue worthy of attention. However, there still existed some debates on the provenance or which source is the dominant to the RSRs. To constrain the provenance of the RSRs, the in-situ micro-area X-ray fluorescence spectroscopy, the statistics of heavy minerals and the detrital zircon U-Pb geochronology are employed in this study. The results show that the heavy mineral combination of the RSRs is amphibole-epidote-iron oxide minerals, and the content of amphibole is much higher than that of epidote. The detrital zircon U-Pb ages yield five significant age ranges of 160-330 Ma (22.89 %, peaking at ~200 Ma), 350-550 Ma (18.61 %, peaking at ~430 Ma), 650-1200 Ma (29.32 %, peaking at ~750-800 Ma), 1700-2000 Ma (10.58 %, peaking at ~1850 Ma) and 2400-2600 Ma (5.09 %, peaking at ~2500 Ma). Through the comparison with the potential source area, we found a strong similarity of the heavy mineral combination and zircon U-Pb ages between the RSRs and Yangtze River (YtR), indicating the YtR as the major source for the RSRs. In addition, the sediments of the ancient Yellow River Delta (AYRD) could have limited impacts on the coast of northern Jiangsu, while the modern Yellow River (YR) possibly only influences the northern edge of the RSRs.