On the Holocene Sea-Level Highstand Along the Yangtze Delta And

ARTICLES Chinese Science Bulletin 2003 Vol. 48 No. 24 2672ü2683 6000ü4500 aBP was a period characterized by the highest sea level of the Holocene, approximately 3.7 m higher On the Holocene sea-level than the current sea level (Fig. 1). highstand along the Yangtze Delta and Ningshao Plain, East China ZHU Cheng1, ZHENG Chaogui1,4, MA Chunmei1, YANG Xiaoxuan1, GAO Xizhen1, WANG Haiming2 & SHAO Jiuhua3 1. Department of Urban and Resources Sciences of Nanjing University, Nanjing 210093, China; 2. Zhejiang Institute of Cultural Relics and Archaeology, Hangzhou 310014, China; 3. Hemudu Site Museum of Zhejiang, Yuyao 315400, China; 4. Department of Chuzhou Normal College, Chuzhou 239012, China Correspondence should be addressed to Zhu Cheng (e-mail: zhuchengnj [4] @yahoo.com.cn) Fig. 1. Various curves of global sea-level changes since 13000 aBP . Abstract The temporal-spatial distribution of Neolithic The Greenland ice-core records[5] seem to support sites shows a long period of absence of human settlements during the early Holocene on the Yangtze Delta, and the area Fairbridge’s viewpoint (Fig. 2). Oxygen isotopic records has not been colonized until 7000 aBP, corresponding to the indicate that 7000ü4000 aBP was the Holocene Thermal onset of the Majiabang culture. Besides the regions east to Maximum, which might have caused an accelerated melt- the sandbar of Maqiao Site in Shanghai, foraminifera are not ing of the Antarctic Ice Sheet, thereby leading to the found in Neolithic cultural layers since 7000 aBP, indicating Holocene sea-level highstand. a widespread transgression between 10000 and 7000 aBP. However, the pattern of global sea-level rise during Evidence of radiocarbon-dated cultural relics, foraminifera the middle Holocene is still uncertain, and there has been and pollen records from the Hemudu Site suggests that the no definitive conclusion on sea-level changes along the Hemudu culture emerged and developed during the [6ü8] mid-Holocene Climatic Optimum. Therefore, the hypothesis Yangtze Delta. Zhao et al. suggest that considerable of a mid-Holocene sea-level highstand along the Yangtze fluctuations of sea level occurred during the Holocene and Delta and Ningshao Plain from 7000 to 5000 aBP is an open the highest sea level occurred between 7500 and 4000 aBP, debate. New evidence from archaeological excavations and wherein the sea level was 2ü3 m higher than that of pre- bio-stratigraphy suggests that, prior to 7000 aBP, a high sea sent. Yan and Xu et al.[9] believe that the sea level was 60 level occurred along the Ningshao Plain. Subsequently, the m at 10000 aBP, and seawater did not inundate the north- sea level was lowered between 7000 and 5000 aBP, and the area suffered from frequent floods from 5000 to 3900 aBP. ern Yangtze Delta where a front delta-shallow sea land- scape developed between 6500 and 5500 aBP. Then, a Keywords: Yangtze Delta, Ningshao Plain, Holocene sea-level high- tidal bank, fork, sand dam, riverbed, and river mouth were stand, Hemudu Site, foraminifera, pollen. in turn formed during the late Holocene. Yang and DOI: 10.1360/03wd0387 The influence of global sea-level rise on human live- lihood in the 21st century has become one of the important topics of the current global changes research. Under- standing past sea-level response to climate changes is necessary to forecast the future. Therefore, searching stratigraphic evidence of sea-level changes from archaeological sites in coastal regions has become one of the characteristic research strategies[1ü3]. Three patterns (cf. Mörner, Shepard and Fairbridge)[4] concerning postglacial sea-level changes have been proposed. One is the con- tinuous pattern, in which sea level rose gradually from the Fig. 2. Air temperature curve of the Earth's surface in the past 18000 a end of the Last Glacial Maximum and reached the present based on ice-core oxygen isotopic ratio records from Greenland[5] (modi- [4] level at about 4000 aBP. However, Fairbrige argues that fied from Houghton et al., 1990[5]). 2672 Chinese Science Bulletin Vol. 48 No. 24 December 2003 ARTICLES Xie et al.[10] documented significant fluctuations of sea elevation of 8 sites are the same as that of the Majiabang level along the eastern Chinese coast during the late-gla- culture with an altitude of 0ü2 m and the elevation of the cial and Holocene. From the last glacial onward, sea level other 4 sites is different. In this time, there were 28 sites rose rapidly and reached the current level along with the with elevation of 2ü5 m (more than those during the Ma- maximum transgression during the middle Holocene. jiabang culture). Among them, the elevation of 21 sites [11] However, according to Wang Fubao , high sea level oc- (including the important newly occurred sites, such as curred at 5000, 3500, 2600 and 1100ü700 aBP, and low Tongli of Wujiang, Dagangzhen of Danyang, Jianbi of sea level appeared at around 6300ü5600, 4500ü4000, Zhenjiang, Lucheng of Wujin, Sidun Sanhuangmiao of and 3000 aBP. The amplitude of these fluctuations varies Zhenglu in Changzhou, Mashan of Wuxi, Tangqiao of from 3 to 4 m. According to Shao Xusheng[12], the maximum Shazhou, Qiandixiang of Xinguang in Changshu and transgression reached the westmost Yangtze Delta over the Zhanglingshan of Wuxian, etc.) differs from those of the period of 6910f540 aBP, and the coastline shifted Majiabang culture. These newly occurred sites with eleva- westward to the line along Wangxian-Pangu-Zhulin- tion of 2ü5 m were distributed mostly in the north and Qingchun-Tangwang-Shetou-Xiangyang to the east of Mt. east Taihu Lake, particularly in the Zhangjiagang-Shazhou Maoshan (However, Neolithic sites distributed densely in region. This phenomenon is the result of the Holocene the region east to this line, where rice cultivation was migration of the Yangtze River channel. Deposition of the originated and also distributed widely in the Yangtze Delta south convex bank of the Yangtze River created enough as well). space for human settlement. Note that although there were What mentioned above indicated that, for a long time, 5 primary sites (3 more than those of the Majiabang cul- most Chinese geologists are in favor of the existence of a ture) with altitude of 2ü5 m and 1 with altitude of 10ü Holocene sea level high and believe that it occurred be- 50 m, Cultural sites with altitude of 0ü5 m were found tween 7000 and 5000 aBP. Nevertheless, archaeological on the bed of the Chenghu Lake of Wuxian, indicating that evidence since the middle of the 20th century seems to no high sea level occurred at that time. prove the contrary conclusion. Most of those 205 Neo- (3) The Liangzhu culture (5000ü4000 aBP ), char- lithic sites with an age range of 7000ü4000 aBP were acterized by jade articles, was the most prosperous pre- ascertained by archaeological instrument typology, ar- historic civilization in the Yangtze Delta. There are 30 chaeological stratigraphy and radiocarbon dating on bur- sites (newly occurred 21) with altitude of 0ü2 m. In con- ied tree trunks and charcoal in the sites. These sites are trast with those of the Songze culture, the situation of located in the seawater-submerged area of high sea level these sites with the same altitude changed to a certain ex- between 7000 and 4000 aBP. tent. The newly occurred sites are the Dasanjin Site of 1 Spatial and temporal distribution of Neolithic sites Tuanjiecun in Wujiang, Huangtushan Site of Mocheng in on the Yangtze Delta Changshu, Maqiao Site in Shanghai, Jiefangcun Site of Figs. 3ü5 demonstrate the distribution of the 205 Luojiajiao in Qingpu of Shanghai, Longnan Site of Mei- archaeological sites during 7000ü4000 aBP on the Yang- yan in Wujiang, Shengjiadai Site of Yanguan in Haining, tze Delta. A total of 34 sites belong to the Majiabang Nanrongzhuang Site adjoins the railway station of Kun- culture, 47 to the Songze culture, and 124 to the Liangzhu shan, Tushandun Site of Zhengdian Town in Qingpu of culture. Figs. 3ü5 demonstrate the distribution character- Shanghai, Tinglin Site of Jinshan in Shanghai, Qianshan- istics of the Neolithic archaeological sites as follows: yang Site of Huzhou in Zhejiang, Tangmiaocun Site of (1) During the Majiabang culture (7000ü5800 aBP), Qingpu in Shanghai, etc. In this period, there was a ten- of the 34 sites, 11 sites were located mostly on the dency that the changing scope of the sites’ location with low-lying and flooding plain to the east and west of Taihu an altitude of 0ü2 m expanded further toward the east Lake; 20 sites are mostly on water-net plain and high-land and south of Taihu Lake. There are 83 sites with an alti- plain to the northwest and southeast parts of Taihu Lake; tude of 2ü5 m, 55 more than those of the Songze culture. and 3 sites are at the mound mesa of the piedmont alluvial Compared with the Songze culture, the location of the plain to the west of Taihu Lake and the lakeshore plain to sites with the same altitude changed to a certain extent. the northeast of Taihu Lake. Therefore, it is clear that, the The 67 newly occurred sites mainly include the Liangzhu Neolithic man began to dwell on lakeshore plains with a Site of Yuhang in Zhejiang, Mojiaoshan Site in Yuhang low and flat terrain (altitude range of 0ü5 m a.s.l.) and (the area covers 300000 m2), Shuitianpan Site in Hang- accessible water sources since 7000 aBP. zhou, Quemuqiao Site in Jiaxing, Zhelin Site of Fengxian (2) During the Songze culture (5800ü5000 aBP), of in Shanghai, etc. The changing range of the sites’ location the 47 sites, 12 sites were located mostly at the low-lying with an altitude of 2ü5 m expanded further to the north, lacustrine plain and lakeshore plain with altitude of 0ü2 east and south of the Taihu Lake.

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