Pollen Assemblage and Sedimentary Environment Evolution in the Coastal Zone in Qinzhou Bay , Guangxi Province
详细信息
- 责任者：Li Zhen(State Key Laboratory of Estuarine and Coastal Research ; East China Normal University ; Shanghai200062 ; China) ; Zhang Weiguo
- 刊名：Quaternary Sciences
- 出版年：2010
- 卷期：30(3)
- 关键词：沉积环境 ; sedimentary environment ; 孢粉组合 ; palynological assemblage ; 钦州湾 ; Qinzhou Bay
- 页码：p.598-608
- 图表：4 illus., 34 refs.
- 分类号：0200
- issnNo：ISSN1001-7410
- isbnNo：CN11-2708/P
摘要
The sedimentary environment evolution of the tidal zone in Qinzhou Bay，Guangxi Province during the last 150 years was studied by pollen and grain size analyses for 4 sediment cores longer than 1 m from 4 boreholes and in combination with sedimentation rates measured with the 210Pb method. In general，the high content of temperate pollen including Fagus in borehole LM01 core and Fagus，Aceraceae，and Juglandaceae in borehole Q24 core indicates that the regional climate in the 19th century was cooler than that at present. In the early 20th century，a rapid decrease of mangrove pollen Rhizophora and Aegiceras reflected a decline of mangrove beaches in the west coastal of Qinzhou Bay. In the 1960s and 1970s，the shoreline in the western area migrated landward and the high tidal flat evolved into the low tidal flat，which can be evidenced by the increased content of the fern spores and Pinus pollen in boreholes LM01，Q24 and Q37 cores. From the 1980s on，accompanied with high accumulation rates，the shoreline in the eastern area migrated rapidly seaward because of much more materials transported by the Qinjiang River，which can be evidenced by more arboreal pollen and Poaceae pollen. Human activities such as reclamation and embankment have also accelerated the evolution from the low tidal flat to the high tidal flat. On the whole，Qinzhou Bay has shown a trend of westward expansion and eastward reduction.