摘要
通过分别对辽东半岛东侧大洋河平原中部的D65孔岩心做连续的硅藻分析,以及对辽东半岛西侧的长兴岛八岔沟古泻湖平原B3孔、下辽河平原的机械钻孔X33及手动钻孔X11和X21等钻孔岩心做连续的粘土混浊水电导率测定,得到各岩心的硅藻图谱/或粘土混浊水电导率图谱。显示出在这些海岸平原均有厚度在6m以上的海相层存在。表明全新世海侵时海水达到并长期占据这些海岸平原。同时还显示在这些海相地层的5～7m深处,普遍存在一层陆相或海陆交互相地层,通过对各地点已有的14C年代数据分析,推测这层陆相层或海陆交互相地层应该形成于全新世海面上升的早全新世—中全新世时期。表明全新世海进期当中,辽宁沿海普遍存在一次海退地质事件。从下辽河平原样品的14C测年数据,推测这次海退时期大致在9300～8000aB.P.(校正年)。
We have carried out the diatom analysis of the cores of hand drilling D65 in the central Dayanghe plain of the eastern Liaodong peninsula, and made the successive electric conductivity measurements on the cores of hand drilling B3 of Bachagou in Changxing island in the west of Liaodong peninsula and on the cores of hand drilling X11 and X21 and mechanical drilling X33 in the lower-reach of Liaohe plain. Based on these diatom analysis and conductivity measurements, we obtained the diatom mappings and electric conductivity mappings of the cores, respectively. It is shown that there are marine facies layers over 6 meters in thickness throughout the plain and indicated that the seawater had reached the coastal plain in the Holocene, and that the transgression of the seawater had occupied the coast for a long period. In addition, it is revealed that there are continental facies or marine-terrigenous facies formation widely deposited beneath the marine facies bed in the depth about 5-7 meters, which indicates that the widespread marine regression event had occurred during the transgressive period in the Holocene. It can be presumed that they were formed in the time span from the early Holocene to the middle Holocene （9 300-8 000 cal. a B. P. ） according to the known 14^C age dating.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2009年第2期396-403,共8页
Earth Science Frontiers
基金
日本笹川研究助成金项目(11-393M)
国土资源部基金项目(40201052)
关键词
全新世海侵
硅藻分析
粘土混浊水电导率
海相层
陆相层
Holocene transgression
diatom analysis
electric conductivity
marine facies bed
continental facies bed
