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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。
Large amount of sediments have been accepted since the Late Cenozoic in the Yangtze River Delta. The long time series of sedimentary stratigraphy research is of great significance to the evolution of sedimentary environment in the delta and the history of the Yangtze River. Based on the geomagnetic, magnetic susceptibility and lithology analysis of the DY03 porphyry in the Yangtze River Delta, the author has initially established a more reliable geochronostratigraphic framework for drilling. It is found that there are several short-term magnetic drift events in the sedimentary sequence of the Yangtze River Delta that have global significance and are of great significance to the further application of the magnetic stratigraphic dating. The analysis shows that the hard clay layer generally developed in the Late Cenozoic strata in the study area is not only an important marker for Late Quaternary stratigraphic correlation but also plays an important role in contrasting the sedimentary strata since the Late Cenozoic. Sedimentary evolution in the Yangtze River Delta basically showed that it was controlled by tectonic activities in the early stage and controlled by sea level rise and fall and climate change in the later period.