琼东南盆地南部隆起带丘状地震相成因讨论

琼东南盆地南部隆起带地震剖面上梅山组普遍存在丘状反射现象,关于该丘状反射存在两种成因认识,即冲刷水道或生物礁。为了辨别梅山组丘状反射成因,分析总结了典型的水道冲刷和生物礁地震反射特征,认为两者在地震相上明显不同:冲刷水道具有典型的下切特征,常呈明显的期次性;生物礁多呈透镜状、塔状,常见上覆岩层的披覆构造。利用地震相分析技术、瞬时属性技术、地层切片技术对丘状反射体进行了识别和刻画,结合琼东南盆地梅山期构造运动的背景,认为该丘状反射为生物礁。

Discussion on the genesis of domal reflections at the uplift zone of the southern Qiongdongnan Basin

Meishan Formation at the uplift of the southern Qiongdongnan Basin commonly displays domal reflections on the seismic section. There are two recognitions on the genesis of the domal reflection formerly,including erosion channels and reef. In order to identify the genesis of the domal reflections,we analyzed and concluded the typical seismic reflection characteristics of channels and reef,which indicates that the two are obviously different. Erosion channels display typical down cutting feature and always shows obvious multiphase. However,reef mostly displays lenticular,tower,commonly draping structure of its overburden. By applying seismic facies analysis,instantaneous attribute and strata slice technique,the domal reflections were identified and characterized. Combined with the tectonic movement background of Meishan stage within Qiongdongnan Basin,the geology body with domal reflections is identified as reef.