Landscape Evolution In The Liangzhu Area Since The Early Holocene: A Comprehensive Sedimentological Approach

The Liangzhu culture (5300- 4300 cal yr BP) is considered to be the testification of the five thousand year history of Chinese civilization, and has thus attracted a great deal of attention from the archaeological community. However, the rise and fall of the Liangzhu culture, especially the cause of its vanishing, is still a topic of intense debate. Since the Liangzhu Ancient City area is a low-lying littoral region with a dense network of waterways, the landscape evolution would have had great impact on human-environment interactions. In this study, we will reconstruct the evolutionary history of the landscape by using sedimentological approach. Five sediment cores, together with trenches exposed in the archaeological sites were investigated. The chronology of the sediments was established by using twelve accelerator mass spectrometry (AMS) C-14 dates. Sedimentary proxies, including calcium content, grain size, diatoms, and dinoflagellates are used for paleoenvironmental reconstruction. The results showed that: (1) from the last deglaciation to the early Holocene (before ca. 9400 cal yr BP), the Liangzhu area was widely exposed, and the cores contain coarse sand, gravel, and hard clay layers; (2) during the early to middle Holocene (ca. 9400 - 7600 cal yr BP), the area was rapidly submerged by a westward marine transgression, and the subsequent marine regression moved eastward from the Liangzhu area at approximately 7900 - 7600 cal yr BP when the rate of sediment supply exceeded the rate of relative sea level (RSL) rise; (3) during the middle to late Holocene (after ca. 7600 cal yr BP), the deposits mainly originated from overbank flooding or from storm surge events rather than from direct RSL rise from ca. 7600 - 6600 cal yr BP. The Liangzhu Ancient City area remained a swamp and an area of salinization until ca. 5100 cal yr BP.