讨论防城湾水动力条件、地貌特征及沉积物组成。其中，水下动力地貌有６种类型：潮间浅滩、潮流冲刷深槽、水下拦门沙坝、水下沙嘴、水下岸坡、海底平原。表层沉积物类型有６种：砂砾、粗砂、粗中砂、中细砂、细砂、粉砂质粘土。沉积物中重矿物组合为钛铁矿—锆石—电气石。沉积物中有孔虫、介形虫，划分为４个组合带：卡纳利拟单栏虫组合；毕克卷转虫变种组合；毕克卷转虫—异地希望虫组合；毕克卷转虫变种—球室刺房虫—异地希望虫组合 Discuss Fangchengwan hydrodynamic conditions, topography and sediment composition. Among them, there are 6 types of underwater dynamic landscape: Intertidal shoal, tidal current scouring deep groove, underwater barrage sand bar, underwater spit, underwater bank slope, seabed plain. There are six types of surface sediments: gravel, coarse sand, coarse sand, fine sand, fine sand, silty clay. Heavy mineral assemblages in sediments are ilmenite-zircon-tourmaline. Foraminifera and ostracods in sediments are divided into four zones: Canary single canola combination; Bike rotavirus variety combination; Insect variant - Ball room Bungee worm - Exotic hope that the worm combination