摘要
长江三角洲地区晚新生代以来接受了大量沉积,长时间序列沉积地层研究对于三角洲沉积环境演化和长江变迁历史都具有重要研究意义。通过对长江三角洲DY03孔古地磁、磁化率以及岩性分析,初步建立了研究钻孔较为可靠的年代地层框架。研究发现,长江三角洲地区沉积序列中有多个具有全球对比意义的短时期磁性漂移事件,对磁性地层定年的进一步应用具有重要意义。分析表明,研究区晚新生代地层中普遍发育的硬黏土层不仅是晚第四纪地层对比的重要标志层,而且对整个晚新生代以来的沉积地层对比都会发挥重要作用。长江三角洲沉积演化基本呈现出早期受构造活动控制,后期受海平面升降和气候变化的制约。
A large amount of sediment has been deposited in the Yangtze River delta area since the late Ce- nozoic, which has important implications for long-term research of sedimentary environmental evolution and changes of the Yangtze River. With methods of paleomagnetism, magnetic susceptibility and lithological analysis, a reliable chronostratigraphic framework of core DY03 in the Yangtze River delta was estab- lished. It is found that there are several short term magnetic excursion events which have global signifi- cance recorded in the sedimentary sequences, and are useful for the further application to the magne- tostratigraphic dating in this area. It is indicated by the analyzed results that hard-clay layers which devel- oped universally in the Cenozoic strata in this area play an important role in the stratigraphic correlation, not only in the late Quaternary but also in the whole late Cenozoic. The sedimentary evolution of the Yangtze River delta, which was controlled by tectonic activities in the early period of formation, has been mainly affected by sea-level fluctuations and climate changes in the followed period.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2008年第6期87-93,共7页
Marine Geology & Quaternary Geology
基金
国家自然科学基金项目(40621063,40830107)
关键词
古地磁
地层
晚新生代
长江三角洲
paleomagnetism
stratigraphy
the late Cenozoie
the Yangtze River delta
