莱州湾南岸XZK2钻孔晚更新世以来的沉积环境探讨

Discussion on Depositional Environment of XZK2 Borehole in South Costal Zone of Laizhou Bay since Late Pleistocene

摘要:

通过钻孔岩性特征、沉积构造及沉积物粒度、磁化率与测井曲线对莱州湾南岸XZK2钻孔上部晚更新世以来的松散沉积物进行了沉积相划分，结合14C同位素年龄测定，划分了深海氧同位素阶段，表明该地区沉积物磁化率与砂含量曲线具有明显的正相关关系，结合已有研究，证明该地区晚更新世以来古环境经历了三次冷暖交替，而莱州湾西南海岸所发现的相当于沧州海侵、献县海侵和黄骅海侵的三次海侵事件，钻孔上仅见全新世黄骅海侵，沧州海侵、献县海侵相应层位为滨海沉积。

Abstract:

Through study on drilling lithology, sedimentary structures, grain size, magnetic susceptibility and logging curve, loose sediments of XZK2 borehole in south coastal zones of Laizhou Bay since late Pleistocene have been divided. Combining with 14C isotopic age determination, the oxygen isotope stages in deep sea have been divided. It is showed that the curve of magnetic susceptibility of sediments and sand content has significant positive correlation. Combining with existing research, it is proved that the ancient environment has experienced in this area three alternating cold and warm since late Pleistocene. Three transgression events which are equivalent to Cangzhou marine transgression transgressive, Xianxian marine transgression transgressive and Huanghua marine transgression have been found in the southwest coast of Laizhou Bay. Through drilling holes study, only Holocene Huanghua transgression can be found, while Cangzhou marine transgression and Xianxian transgression are corresponding with coastal deposition layers.