闽北近岸海域晚更新世以来沉积地层特征及其演化

根据2015年青岛海洋地质研究所地质调查船在闽北近岸海域采集的3 500 km高分辨率的浅层地震剖面资料,结合所处海域水深35~40 m、长度90.2 m、穿过测线Z3和测线L9地震剖面的交叉处的一口地质岩芯ECS1601的分析,对闽北近岸海域晚更新世以来的沉积地层进行了精细的划分。研究结果表明:闽北近岸海域浅层地震剖面,可以识别出5个地震层序,自上而下分别为SU1(QT0-QT1)、SU2(QT1-QT2)、SU3(QT2-QT3)、SU4(QT3-QT4)、SU5(QT4-QT5);根据沉积特征和测年数据,地质岩芯ECS1601可以划为4个沉积地层单元,从上往下依次命名为DU1、DU3、DU4、DU5(DU5a、DU5b、DU5c)。将两者进行对比发现,SU1对应于DU1,SU3对应于DU3,SU4对应于DU4,SU5对应于DU5。综合分析地震剖面和地质浅钻,建立了闽北近岸海域的年代地层框架和沉积地层演化模式,探讨了研究区的沉积演化过程。

Sedimentary Stratigraphic Characteristics and Evolution since the Late Pleistocene in the Offshore Area of Northern Fujian

A 3 500 km high-resolution shallow stratigraphic seismic profile data was collected by the geological investigation ship of the Qingdao Institute of Marine Geology in 2015 in the coastal waters of northern Fujian. Combining the analysis of a core from geological borehole ECS1601 at depths 35-40 m with a length of 90.2 m at the intersection of survey line Z3 with line L9 of the seismic section, the sedimentary strata since the Late Pleistocene were found to be finely divided. The analysis identified six major seismic reflection interfaces (QT0, QT1, QT2, QT3, QT4, QT5 from top to bottom) in the seismic section. The reflective interfaces were divided into five seismic sequences (SU1, SU2, SU3, SU4, SU5 from top to bottom). Micropaleontological and OSL dating data indicated that the core was divided into six sedimentary stratigraphical units (DU1, DU3, DU4, DU5a, DU5b, and DU5c from top to bottom). Finally, the seismic section and geological shallow drilling were comprehensively analyzed to establish the chronological framework and sedimentary stratigraphic evolutionary patterns of the nearshore waters of northern Fujian. The sedimentary evolution process of the study area is discussed.