渤海莱州湾晚第四纪底栖有孔虫分布特征及古环境意义

发布时间：2018-09-14 12:11

【摘要】：通过对渤海莱州湾GK138、GK111及GK95孔的255个沉积物样品中的有孔虫定量统计分析,共鉴定出底栖有孔虫15属32种。根据底栖有孔虫的丰度和分异度等分布特征和AMS14 C和光释光(OSL)测年结果,揭示晚第四纪以来研究区共发育3套海相地层,分别是中更新世晚期的第三海相层、晚更新世的第二海相层和全新世的第一海相层,通过与全球海面变化曲线对比,发现其与MIS7、MIS5和MIS1阶段的高海面有良好的对应关系。样品的Q型聚类及主成分分析划分出3组代表不同沉积环境的有孔虫化石组合,第Ⅲ化石组合带为中更新世晚期海侵的产物,为河口-滨岸浅海环境。第Ⅱ化石组合为晚更新世海侵的产物,为潮间带-潮下带沉积环境,第Ⅰ化石组合带为潮上带-潮间带沉积环境。海相地层顶、底板高程和厚度的分析结果显示中更新世晚期至晚更新世期间发生过不同期次、不同强度的构造活动,而进入全新世以后构造活动相对减弱。
[Abstract]:A total of 32 species of benthic foraminifera belonging to 15 genera were identified by quantitative statistical analysis of foraminifera in 255 sediment samples from GK138,GK111 and GK95 holes in Laizhou Bay of Bohai Sea. According to the distribution characteristics of benthic foraminifera abundance and differentiation and AMS14 C and (OSL) dating, it is revealed that three sets of marine strata have developed in the study area since the late Quaternary, respectively, which are the third marine strata in the late Middle Pleistocene. By comparing the second marine layer of late Pleistocene and the first marine layer of Holocene with the global sea surface variation curve, it is found that there is a good correspondence between the second marine layer and the high sea level in MIS7,MIS5 and MIS1 stages. The Q cluster and principal component analysis of the samples can be divided into three groups of foraminiferal assemblages representing different sedimentary environments. The third fossil assemblage zone is a product of the late Middle Pleistocene transgression and a estuarine shoreline shallow sea environment. The second fossil assemblage is the product of late Pleistocene transgression and belongs to the intertidal to subtidal sedimentary environment and the first fossil assemblage to the upper tidal and intertidal sedimentary environment. The results of the analysis of the top, bottom height and thickness of the marine strata show that the tectonic activity of different intensity occurred during the late Middle Pleistocene to the late Pleistocene, but the tectonic activity weakened relatively after entering the Holocene.
【作者单位】：山东科技大学地球科学与工程学院;山东省地质调查院;
【基金】：中国地质调查局“山东半岛蓝色经济区地质环境调查评价”项目(编号1212011220001) 山东科技大学研究生科技创新基金项目(编号YC150320)共同资助
【分类号】：P618.13

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