一、地质、沉积、地貌背景 珠江口外西侧近岸海岛主要包括荷包岛,高栏岛,三灶岛,交杯沙滩,大、小杧洲岛,大、小横琴岛等。岛屿空间展布受燕山运动控制,主要表现为断裂及伴随的岩浆活动。本文仅涉及砂质沉积比较发育的高栏、三灶、大横琴和交杯沙,即“三岛一滩”。 I. Geology, Sediment and Geomorphology Background The coastal islands on the west side of the Pearl River estuary mainly include Puao Island, Gaolan Island, Sanzao Island, Jiaobei Beach, Xiaobei Island, and Xiaoqin Island. The spatial distribution of the island is controlled by the Yanshan movement, which is mainly characterized by faults and accompanying magmatism. This article deals only with Gaolan, Sanzao, Daqinqin and Sanda Sand which are relatively well developed in sandy sediment, namely, “Three Islands and One Beach.”