长江口北支有孔虫组合及其环境意义  

The Foraminiferal Assemblages and Its Paleoenvironmental Implications in the North Branch,Yangtze Estuary

作　　者：周开胜[1,2] 孟翊[3] 刘苍字[3] 洪雪晴[2] 

机构地区：[1]蚌埠学院食品与生物工程系,安徽蚌埠233030 [2]华东师范大学地理系,上海200062 [3]华东师范大学河口海岸国家重点实验室,上海200062

出　　处：《沉积学报》2009年第2期334-342,共9页Acta Sedimentologica Sinica

基　　金：国家重大基础研究发展规划项目(编号:2002CB4124);国家自然科学基金项目(批准号:40676028);国家自然科学青年基金项目(批准号:40206013);安徽省自然科学研究项目(KJ2008B195);蚌埠学院自然科学研究项目(BBXY2007-207B);蚌埠学院优秀人才计划专项资助

摘　　要：通过对长江口北支XL1、XL2和CY孔有孔虫组合进行对比分析,综合沉积物粒度特征和环境磁学特征,探讨了长江口北支沉积环境水动力条件演变特点。揭示了长江口北支各沉积相所对应的有孔虫组合,即潮流沙脊以E.naraensis、E.magellanicum和F.decorus组合为主;潮汐水道以A.convexidorsa、E.naraensis、E.magellanicum和A.bec-cariivars.组合为主;潮滩有孔虫组合则以A.beccarii vars.、E.magellanicum、E.naraensis和滨海沼泽特征种T.inflata及J.macrescens组合为主;河口沙坝则以A.beccarii vars.、E.naraensis等组合为主的沉积特征。On the basis of comparative analysis of foraminiferal assemblages zones for Holes XL1, XL2 and CY, integrating the characteristics of their aggradation and environmental magnetism, we probe into the evolvement of the deposit hydrodynamic condition in the North Branch, the Changjiang River Estuary. At the same time, it reveals the relation of sedimentary facies corresponding to their foraminiferal assemblages zones. That is the tidal current ridge corresponding to the E. naraensis, E. magellanicum and F. decorus assemblages zone; tidal channel to the A. convexidorsa, E. naraensis, E. magellanicum and A. beccarii vars. assemblages zone; supratidal zone to the A. beccarii vars. , E. mageUanicum, E. naraensis speciesassemblages zone, especially the T. inflate and J. macrescens are its characteristic species; sand dam to A. beccarii vars E. naraensis, et al. assemblages zone. The above sedimentary characteristics imply the function of tidal current during the burial of foraminiferal assemblage zones. Based on foraminiferal assemblages zones, magnetic properties and lithofacies, we also suggest that there are three modes of sedimentary environment for Hole XL1 , XL2 and CY in the North Branch estuary, the Changjiang River Esturary： tidal current ridge→tidal channel→supratidal zone, forming the sedimentary facial sequence of the filled estuary.

关 键 词：长江口北支 有孔虫 沉积环境 

分 类 号：P512.2[天文地球—地质学] Q141[生物学—生态学]