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涠洲岛(图1)位于我国广西壮族自治区北海市以南36海里,面积约26km~2,形状椭圆,南部海拔76.0—79.8m,北部海拨11—13m,向北平缓倾斜,是一个在更新世时期由火山喷发而形成的海岛。共有两个火山口,一个在南湾正南方约500m远的海中,另一个在岛的东部横岭山,海拔16.7m。岛的本部主要出露灰黑色橄榄玄武岩和火山碎屑岩,表土为火山碎屑岩的风化物及新生界含生物碎屑的砂泥沉积,丛生亚热带型的乔木、灌木和草本植
Weizhou Island (Figure 1) is located 36 nautical miles south of the Beihai City in Guangxi Zhuang Autonomous Region of China with an area of about 26km ~ 2 and an oval shape. The southern elevation is 76.0-79.8m and the northern elevation is 11-13m. The islands formed by volcanic eruptions during the Pleistocene. There are two craters, one in the sea about 500m south of Nanwan and the other at the Hengling Mountain in the east of the island, at an elevation of 16.7m. The main part of the island is exposed with gray-black olive basalt and pyroclastic rocks, topsoil with volcaniclastic weathering materials and Cenozoic bioclastic sediment deposition, tufted subtropical trees, shrubs and herbs