AMS^(14)C测年揭示的渤海湾沿海低地第Ⅱ海相层年龄(Ⅱ)  

The age of the second marine layer in coastal lowland of Bohai Bay revealed by AMS^(14)C dating method(Ⅱ)

作　　者：商志文[1,2] 王福[1,2,3] 李建芬[1,2] 姜兴钰[1,2] 陈永胜[1,2] 王宏[1,2] 

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]中国地质调查局泥质海岸带地质环境重点实验室,天津300170 [3]天津地质矿产研究所年轻沉积物测年实验室,天津300170

出　　处：《地质通报》2016年第10期1607-1613,共7页Geological Bulletin of China

基　　金：中国地质调查局项目(编号:12120113005800、12120100600015008);国家自然科学基金项目(批准号:41476074)

摘　　要：在初步获得渤海湾海河南部沿海低地第Ⅱ海相层年龄大于43.5ka BP的基础上,在沧州北部和海河北部的沿海低地又利用6个新的机械钻孔岩心,建立了2条垂直于现代岸线的长剖面。根据沉积物岩性和有孔虫查明了第Ⅱ海侵层在剖面中的空间分布,并获得一组新的AMS^(14)C年龄数据。结果显示,在第Ⅱ海相层中新获得的9个AMS^(14)C年龄同样均大于43.5ka BP。至此,渤海湾3条垂直现代岸线剖面10个钻孔的第Ⅱ海相层的21个AMS^(14)C年龄均大于43.5ka BP,进一步证实了普遍发育于渤海湾沿海低地的第Ⅱ海相层形成于MIS 3阶段早期或MIS 5阶段,而不是前人认为的23~39ka BP。Preliminary result has indicated that the age of the second marine layer in the southern coastal lowland of Bohai Bay is 〉 43.5ka BP. Recently’ six boreholes have been drilled in the coastal lowlands north of Cangzhou and north of the Haihe River’ and two new profiles perpendicular to the moder^i shoreline were then established. Combined with the lithostratigraphy’ foraminiferal as-semblages and AMS 14C dating results’ the second marine layer in these cores has been identified spatio-temporarily. The dating re-sults of 9 samples collected from the second marine layer show that the ages are all older than 43.5ka BP. Up till now’ 21 AMS 14C ag-es collected from the second marine layer in 10 boreholes’ given by the authors’ indicate that the widely distributed second marine layer was formed in the early MIS 3 or MIS 5 stages rather than 23？ 39ka BP as previously believed.

关 键 词：ams14c测年 Ⅱ海年龄 沿海低地 渤海湾 

分 类 号：P736.223[天文地球—海洋地质]