ZHANG Kai, LING Ken, LIU Chunlian, et al. Holocene diatom records in the Rongjiang Plain and implications for palaeoenvironmental changes[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 2020,59(3):32-42.
ZHANG Kai, LING Ken, LIU Chunlian, et al. Holocene diatom records in the Rongjiang Plain and implications for palaeoenvironmental changes[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 2020,59(3):32-42. DOI: 10.13471/j.cnki.acta.snus.2020.03.004.
通过对榕江平原揭阳地区钻孔ZK01和ZK02硅藻记录的分析,结合沉积学特征和年代数据,重建榕江平原全新世以来的古环境演化。约10.4~8.5 ka B.P.,钻孔所在地尚未受到海水影响,发育河漫滩-淡水沼泽环境。8.5~5.5 ka B.P.海水入侵,形成潮间带沼泽-潮滩相沉积。5.5~3.9 ka B.P.本区为河口湾环境,约5.5 ka B.P.海侵影响达到最大,硅藻总丰度和分异度达到最高值。3.9~3.7 ka B.P.发生一次短暂海退,硅藻总丰度明显下降,ZK01孔发育咸水沼泽相沉积,ZK02孔仍为河口湾相沉积。3.7~2.4 ka B.P.海平面再次上升至相对稳定,研究区持续发育河口湾环境,期间出现3次小规模的水深变化旋回。2.4 ka B.P以来海水退出,河流作用增强,研究区发育三角洲平原相沉积。
Abstract
Holocene palaeoenvironmental reconstruction was carried out based on diatom records
together with sedimentology analysis and dating results of boreholes ZK01 and ZK02 from the Rongjiang Plain. A flood plain-freshwater swampy environment developed between
10.4 and 8.5 ka B.P..
During this time the seawater has not intruded into the study area yet. At around
8.5ka B.P.
diatoms showed up for the impact of seawaters and the environment was characterized by an intertidal marsh. Between
5.5 and 3.9 ka B.P.
an estuary environment dominated in the study area with the rapid transgression. The maximum transgression occurred around 5.5 ka B.P.
evidenced by the highest abundance and diversity of diatoms. A short-time regression occurred between 3.9 and 3.7 ka B.P. while a brackish marsh environment existed. From 3.7 to 2.4 ka B.P.
the sea level gradually rose to a stable level and an estuary environment developed. Three short-term fluctuations were recorded by diatoms in this period
indicating changes in water depth and salinity. Since 2.4 ka B.P.
the seawater retreated and an alluvial plain developed in the study area.