Environmental and provenance change since MIS 2 recorded by two sediment cores in the central North Jiangsu Plain, East China

Abstract

In order to reveal the evolution of sediment provenance and paleoenvironment of the central North Jiangsu Plain (NJP) since marine isotope stage 2 (MIS 2), we analyzed lithology, accelerator mass spectrometry (AMS) 14C dating, macrofossils and foraminifera, grain size, and geochemical compositions of sediments from two sediment cores (Core M and Core Y) recovered in the northern side of the Yangtze River. Our results show that fluvial environments prevailed in the central NJP during MIS 2, followed by alternations of coastal-marsh environments and shallow-bay environments in north central NJP and coastal-marsh environments in south central NJP during MIS 1. Provenance analysis suggests a major change in sediment provenance from the Yangtze River to the Yellow River at early MIS 1 in north central NJP; these Yellow River sediments might be transported from previously deposited sediments by strong tidal currents and intense waves to this area or be a reflection of a southward shift of the Yellow River during this period. However, the Yangtze River-derived sediments dominated the south central NJP since MIS 2. The depositional succession and sediment supplies since MIS 2 were dominantly controlled by sea-level fluctuations, regional geomorphic patterns, shift of the rivers, etc.