黄河三角洲沉积环境和沉积模式

SEDIMENTARY ENVIRONMENT AND MODEL OF THE YELLOW RIVER DELTA

由于特殊的气侯、地理、河口区构造背景、黄河及蓄水体水动力等沉积条件.黄河三角洲形成了独特的沉积环境和沉积模式.经过实地考察和研究认为.黄河三角洲属于高建设性的扇形三角洲.可以划分为三角洲平原、三角洲前缘和前三角洲.三角洲平原包括分流河道、废弃河道、堤岸、沼泽、盐碱滩和风成沉积等微环境.黄河三角洲平原发育盐碱滩,与密西西比河三角洲经典模式有本质区别.三角洲前缘包括水下分流河道、水下分流间湾、水下天然堤和决口扇、河口砂坝、远砂坝和三角洲前缘席状砂等徽环境.现代黄河三角洲沉积环境和沉积模式研究对于古代三角洲研究以及开发和治理黄河三角洲具有十分重要的意义.

Owing to the special deposition conditions of climate, geography, tectonics setting in the river mouth area. and the hydrodynamic factors within the receiving basin, the Yellow River delta is characterized by unique sedimentary environment and model. Field investigation and study showed that the Yellow River delta is a high-constructive fan-like delta which can be divided into delta plain, delta front and pro-delta. The delta plain can be subdivided into microenvironments, including distributary channels, abandoned channels, natural levee and overbank splays, marshes, salinized land and eolian deposits, etc. There is essential differentiation between the Yellow River delta and the classical model of Mississippi river delta. The salinized land was developed on the Yellow River delta plain. The delta front associated with subaqueous environment consists of micro-environments, including distributary channels and crevasse splay, interdistributary bays, subaqueous natural levees, mouth bar, distal bar and delta front sheet sand, etc.