花东盆地晚中新世以来沉积演化特征

Sedimentary evolution characteristics since late Miocene in the Huatung Basin

利用近年来在台湾东部海域采集的多道地震和多波速测深资料,对该海域花东海盆区晚中新世以来的沉积充填演化特征进行描述和分析。通过对花东海盆区域地形特征描述、层序地层格架的建立和地震剖面的解译,在本区晚中新世以来的沉积充填中刻画出6种典型地震相类型,并分析其对应的沉积相类型,包括浊积扇、浊积水道充填、块体流、沉积物波、海底峡谷-伴生沉积物滑塌变形-充填、深水扇沉积。结合地震相平面分布及垂向沉积相叠置关系,将晚中新世-第四纪沉积充填演化划分为3个阶段:晚中新世晚期开始受到块体流冲蚀阶段,到海底峡谷冲刷-沉积物失稳-峡谷充填-再侵蚀阶段,到峡谷输送的大量沉积物在上新世以来主要堆积发育了沉积物波、浊积扇、深水扇等沉积体系阶段。

Using the multi-channel and multibeam bathymetry data collected in the eastern Taiwan sea area in recent years, the sedimentary and filling evolution characteristics of the Huatung Basin since the late Miocene in the eastern Taiwan sea area have been described and analyzed. Through the description of the regional topographic features of the Huatung Basin, the establishment of the sequence stratigraphic framework and the interpretation of seismic profiles, six types of seismic facies are identified in the Huatung Basin since the late Miocene, and their corresponding sedimentary facies types are analyzed, including turbidite fan, turbidite channels, mass transport deposits,sediment wave, slump deformation associated with canyon and deep-water fan. According to the plane distribution of seismic facies and vertical stacked patterns between sedimentary facies, the three phases of sedimentary evolution since the late Miocene in the Huatung Basin were rebuilt, which were mass transport deposits in the late Miocene, followed by sediments failures, erosion and sedimentation of submarine canyons and finally, a large number of sediments were unload and developed sediment wave, turbidite fan and deep water fan.