热带地理 ›› 2016, Vol. 36 ›› Issue (3): 388-398.doi: 10.13284/j.cnki.rddl.002851

• 论文 • 上一篇    下一篇

珠江口岛屿全新世沙堤的年代与沉积环境

万一兴1,郑 卓1,萧一亭2,汤永杰1,陈 聪1   

  1. (1.中山大学 地球科学与地质工程学院,广州 510275;2.珠海市博物馆,广东 珠海 519000)
  • 出版日期:2016-05-05 发布日期:2016-05-05
  • 通讯作者: 郑卓(1956―),男,广东人,教授,博士生导师,主要从事第四纪地质学、全球变化科学、古环境生态学、环境考古学、海岸带环境地质与地质灾害研究,(E-mail)eeszzhuo@mail.sysu.edu.cn。
  • 作者简介:万一兴(1991―),女,新疆人,硕士研究生,主要从事第四纪古环境研究,(E-mail)jane.wyxing@gmail.com
  • 基金资助:
    国家自然科学基金(41230101)

Dating and Sedimentary Environment Reconstruction of Holocene Beach Profile in the Pearl River Estuary Islands

WAN Yixing1,ZHENG Zhuo1,XIAO Yiting2,TANG Yongjie1,CHEN Cong1   

  1. (1.Department of Earth Sciences and Geological Engineering,Sun Yat-sen University,Guangzhou 510275,China; 2.Zhuhai Museum,Zhuhai 519000,China)
  • Online:2016-05-05 Published:2016-05-05

摘要: 通过对珠江口岛屿小型海湾如珠海淇澳岛和澳门黑沙滩一级阶地上的古沙坝/沙丘进行光释光(OSL)年代测定、粒度分析,结果表明,全新世潮间带砂体沉积的底部年代根据光释光测年结果和沉积速率推算,超过9 ka。海岸带形成的古沙坝或风成砂质沉积的光释光测年结果大部分老于新石器文化堆积的器物年代,表明全新世高海面期砂质滨海相沉积的形成先于新石器人类活动遗迹。潮间带砂质滨海相沉积的上覆地层常在6.5 ka左右快速转变为潮上带的风成沉积-人类活动混合堆积,导致文化层中沉积物粒度分选变差,参数波动较大。淇澳岛小沙澳湾9―4.3 ka的滨海相砂质沉积的顶部目前位于海拔+4.8 m,这一高程可能与构造抬升运动有关。

关键词: 珠江口岛屿, 全新世, 滨海相沉积, 粒度分析, 光释光, 海平面

Abstract: Holocene sand flat and sand dune deposits, which may be formed during the high sea level period in Holocene, are widely distributed in the coastal zone and islands of the Pearl River Estuary. These deposits contain rich information on Holocene marine transgression and environmental changes. Furthermore, rich Neolithic remains are found in these sediments in the islands around the Pearl River Estuary. Therefore, the coastal sandy marine deposits of Holocene, with evidences of both natural and cultural histories, have drawn great attention from scientists. In this paper, optical stimulated luminescence (OSL) dating and grain-size analysis were conducted. The results showed that the bottom of the coastal sandy marine deposits of Holocene might be formed more than 9 ka B.P. ago. Most of the OSL dating results showed that the Holocene sand flat and sandy eolian deposits were older than the Neolithic remains, which indicated that the former was formed before the latter. Another finding was that the overlying strata of the coastal sandy marine deposits often shifted rapidly to alluvial face of supratidal zone or dune at about 6.5 ka B.P., resulting in worsened grain-size sorting and great parameter fluctuations. The marine facies reached +4.8 m (modern elevation), which might be related to regional tectonic movement or the descending of sea level in Holocene. Combining grain-size analysis and archaeological excavation remains with other relevant records, the Holocene sedimentary environment was reconstructed; sea level change and differential tectonic movement, and relationship between man and nature in Holocene were revealed.

Key words: Pearl River Estuary Islands, Holocene, littoral deposit, grain-size analysis, optical stimulated luminescence, sea level