闽北近岸海域末次盛冰期古河道体系平面展布以及垂向反射特征

根据采集的3 500 km浅地层剖面资料，对闽北近岸海域末次盛冰期古河道体系的平面展布特征(宽度、深度变化特征)和垂向剖面反射特征(反射界面、层序内部反射特征)进行了详细的描述，系统地分析了研究区在末次盛冰期古河道体系的平面展布和古河道典型断面反射特征，初步推测了其起源及形成时的地质环境。结果表明：①研究区内存在一个古河道体系，结合当时古地形及地理位置综合分析，古河道分布与当时海底的地形变化大致对应，推测其中一条走向大致为EW向的古河道可能来源于闽江，另外一条走向为SN向的古河道可能来源于长江支流，具体起源尚待进一步探讨；②进一步验证了自末次盛冰期以来，研究区从发生海退裸露地表发育古河道到再次遭受海侵形成浅海环境的历史变迁。

SPATIAL DISTRIBUTION AND VERTICAL REFLECTION OF THE RIVER SYSTEMS IN COASTAL WATERS OFF NORTH FUJIAN IN LAST GLACIAL MAXIMUM

3 500 km shallow seismic profiles are acquired from the nearshore area off the North Fujian for study of the spatial distribution pattern, such as width and depth variations, and vertical reflection characteristics, such as interface reflection and internal boundaries, of the fluvial system prevailed in the Last Glacial Maximum. Based upon the data, we made a systematic investigation of the paleo-river system. Results show that: (1) A paleo-river system occurred in the study area. The distribution of the rivers roughly follows the current submarine topography. One of the paleo-river courses roughly in east-west direction might be from the Minjiang River, another one, which is in north-south direction, might be derived from one of the tributaries of the Yangtze River. (2) The area which is exposed to air in Last Glacial Maximum was flooded by the transgression later on.