梁钰莹^1,,
李冬玲^1,,,
沙龙滨¹,
舒军武²,
王伟铭²
1. 宁波大学地理与空间信息技术系, 浙江 宁波 315211
2. 中国科学院南京地质古生物研究所, 资源地层学与古地理学重点实验室, 江苏 南京 210008

基金项目: 国家自然科学基金项目（批准号：41302134和41371207）、中国科学院战略性先导科技专项项目（批准号：XDA05120101）、浙江省自然科学基金项目（批准号：LY17D060001）和华东师范大学河口海岸学国家重点实验室开放专项项目（批准号：SKLEC-KF201708）共同资助


详细信息

作者简介: 梁钰莹, 女, 25岁, 硕士研究生, 自然地理学专业, E-mail:liangyuying93@163.com

通讯作者: 李冬玲, E-mail:lidongling@nbu.edu.cn

中图分类号: Q949.27⁺1;P941.78

收稿日期:2018-02-28
修回日期:2018-05-07
刊出日期:2018-07-30

Early to mid-Holocene sedimentary environment evolution in Xianghu Lake area, Zhejiang Province, based on a diatom record

Liang Yuying^1,,
Li Dongling^1,,,
Sha Longbin¹,
Shu Junwu²,
Wang Weiming²
1. Department of Geography & Spatial Information Techniques, Ningbo University, Ningbo 315211, Zhejiang
2. State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, Jiangsu


More Information

Corresponding author: Li Dongling,E-mail:lidongling@nbu.edu.cn

MSC: Q949.27⁺1;P941.78

--> Received Date: 28 February 2018
Revised Date: 07 May 2018
Publish Date: 30 July 2018


摘要
摘要:通过对浙江省萧山湘湖地区XH-2孔上部24 m（全新世以来）沉积物的粒度及硅藻组合进行分析，揭示了研究区早-中全新世期间的沉积环境及相对海平面变化。结果显示，约9300~8850 cal.a B.P.期间，淡水硅藻占绝对优势，半咸水种含量极少，表明湘湖地区当时基本未受海水影响，主要为淡水环境；8850~8550 cal.a B.P.期间，半咸水硅藻含量上升，但整个硅藻组合中仍以淡水硅藻为主，表明湘湖地区虽仍以淡水环境为主，但开始受到间歇性潮汐或风暴潮的影响，对应潮上带的沉积环境；8550~8150 cal.a B.P.期间，淡水种硅藻显著减少，半咸水种、沿岸种及海水种含量增加，表明湘湖地区当时受海水影响显著，对应潮下带的沉积环境；8150~7700 cal.a B.P.期间，淡水种含量开始逐渐回升，海水种含量减少，表明湘湖地区受海水影响开始减弱；7700 cal.a B.P.以后几乎没有发现硅藻，研究区当时可能已经为陆地环境，古人类开始居住，对应于跨湖桥文化（8000~7000 cal.a B.P.）的出现与发展。综合XH-2孔上部24 m沉积物中的粒度变化及硅藻组合结果，发现该地区在8550~8150 cal.a B.P.期间可能存在一个海平面上升事件，该事件在长江三角洲、东南亚甚至世界其他地区均有记录，其成因很可能与全新世早-中期劳伦泰德冰盖融水事件以及Agassiz和Ojibway两个冰川湖溢水事件导致的全球海平面快速上升有关。
关键词: 湘湖/
硅藻/
沉积环境/
全新世

Abstract:Xianghu Lake is located in the Ningshao Plain and very close to the Kuahuqiao archaeological site. A 60-m-long core named XH-2(30°07'17″N, 120°11'38″E) was collected in the Xianghu Lake area, and we analyzed the diatom assemblages and grain size of 24-m-long in upper core XH-2 to study the sedimentary environment evolution during the Early to mid-Holocene in this area. The diatom records show that freshwater species were dominant during 9300~8850 cal. a B.P.(2400~1900 cm) whereas brackish water species were rare, indicating a freshwater environment in the Xianghu Lake area, with little influence of seawater. A remarkable increase in brackish water species occurred at the interval 8850~8550 cal. a B.P.(1900~1550 cm), but freshwater species are still dominated this period, which indicates that tidal water especially storm tide had an intermittent impact on the Xianghu Lake area, corresponding to a supratidal sedimentary environment. Abrupt increase in the abundance of marine and costal water species with the remarkable decline in the freshwater species characterized the period of 8550~8150 cal. a B.P.(1550~1175 cm), which indicated strong influence of seawater on the Xianghu Lake area, inferring an obviously subtidal sedimentary environment. At the interval 8150~7700 cal. a B.P.(1175~950cm), there was a gradually increase in freshwater species and decrease in marine species. This implies the weakened impact of seawater on the Xianghu Lake area. Diatoms disappeared after 7700 cal. a B.P., possibly resulted from the land exposure due to the decelerated sea level rise, when the Kuahuqiao culture developed during 8000~7000 cal. a B.P. The rapid sea level rise based on the diatom and grain size record in Xiang Lake area during 8550~8150 cal. a B.P. corresponded well with records from the Yangtze delta, Southeast Asia and other places in the world. And the rapid deglaciation of the Laurentide Ice Sheet and Agassiz-Ojibway outbrust flood may cause rapid sea-level rise in Xianghu Lake area during the early to mid-Holocene.
Key words:Xianghu Lake area/
diatom/
sedimentary environment/
Holocene



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