【摘要】 河口湾由一套变化明显的复杂的亚环境组成。对其相模式研究标明 ,河口湾沉积特征及岩相分布受波浪、潮汐和河流三种水动力所控制 ,据此可将河口湾分成潮控河口湾和浪控河口湾 .在典型的浪控河口湾中 ,潮汐影响小 ,河口处波浪作用相对较高 .波浪作用促使河口处形成水上障壁或水下砂坝 .这种障壁阻止了大部分波能进入河口湾 ,形成了三分性明显的岩相分带 ;而在潮控河口湾处潮汐能量超过波浪能量 ,主要发育长形潮汐砂坝 .由于潮汐伸入湾头方向比波浪远 ,因此 ,潮控河口湾的岩相三分性不明显 .更多还原

【Abstract】 Estuaries consist of a complex set of intergraditional subenvironments that display considerable variation. Study on the facies models indicates that sedimentary features and the distribution of lithofacies of estuaries are controlled by the interplay between marine processes (waves and tides) and fluvial processes. Estuaries can be divided into wave-dominated estuary and tide-dominated estuary. In a typical wave- dominated estuary, tidal influence is small and the mouth of the system experiences relatively high wave energy. These waves cause sediment to move alongshore into the mouth of the estuary where a subaerial barrier/spit or submerged bar is developed. This barrier prevents most of the wave energy from entering the estuary. This distribution of total energy produces a clearly-defined tripartite distribution of lithofacies. Tide-current energy exceeds wave energy at the mouth of tide-dominatde estuaries, and elongate sand bars are typically developed. Tidal energy penetrates further headward than wave energy, thus the tripartite facies distribution is not as obvious as that of wave-dominated estuaries.更多还原