摘要
对渤海湾西岸CH114孔岩心全新世沉积硅藻进行了系统研究，发现硅藻17属28种。与沉积岩石学、年代学（AMS 14C）研究相结合，将该孔自下而上划分为6个硅藻组合带，显示研究区全新世以来经历了从陆到海的演化过程：全新世初期为陆相（组合1带下部）至受海水影响的盐沼低地环境（组合1带上部）；6646~4280 cal BP年间为受风暴强力事件影响的浅海环境（组合2带）；4280年以来为水深不断变浅的浅海环境（组合3-6带）。CH114孔沉积速率的阶段性变化与河流供给有较好的对应关系：3.6~2.6 ka cal BP和0.4ka cal BP以来两个时段相对较高的沉积速率，分别与黄河三角洲超级叶瓣5的形成和海河独立入海相对应。由硅藻记录的海洋影响的波动变化与全新世气候变化对比显示：研究区海洋影响的增强与气候变暖具有一定的正相关性。CH114孔全新世以来陆海环境的演化，总体上是对气候与海面变化的响应。
The diatoms of the borehole CH114,located on the west coast of the Bohai Bay,have been systematically stud-ied,and 28 species in 17 genera were identified. Six diatom zones have been divided according to the characteristics of the diatom assemblages,the sediments and AMS 14C chronological framework of the borehole as well. The diatom and chronos-tratigraphical results revealed that the study area was changed from the lacustrine to the marine environment in the Holocene. The diatom zone 1,indicating the beginning of the Holocene,was from the terrestrial environment to salt marsh environment which was influenced by the sea water. Zone 2 indicated a shallow sea environment which was affected by storms during 6 646~4280cal BP. Since 4 280 cal BP,the area entered a long period of shallow sea environment with the water depth de-creased（zone 3 to 6）. The sedimentation rates of the borehole CH114 have a good relationship with the sediment supply. The high sedimentation rates during 3.6~2.6 ka cal BP and since 0.4 ka cal BP were corresponding to the formation of super lobes five of the Yellow River Delta and Haihe River independently flowing into the sea respectively. Comparison between the di-atom-based marine influence curve and the Holocene climate change showed that the increase of the marine influence almost corresponded positively to those warm periods. Generally,the Holocene environmental evolution was governed mainly by the climate and sea level change.
出处
《海洋通报》
CAS
CSCD
北大核心
2013年第5期527-534,共8页
Marine Science Bulletin
基金
中国地质调查局项目(12120113005800
1212011120169)
天津市海域地质地貌调查项目(908-TJ-06)
关键词
渤海湾
全新世
沉积环境
海洋影响
河流供给
Bohai Bay
Holoeene
sedimentary environment
marine influence
sediment supply
