1.地质背景金岛位于巴斯海峡西部入口处,大致在东南面的塔斯马尼亚和北面的维多利亚之间的中途地段(图1)。金岛南北长约60公里,最大宽度为25公里,较浅的海底山脊从塔斯马尼亚向北北西伸展。这个山脊界于两个重要的中生代—第三纪沉积盆地之间,东边为巴斯盆地,西边为奥特韦盆地。这些盆地是在中生代时期由于与冈瓦纳大陆解体有关的构造活动复活而形成的。 1. Geological Background Gold Island is located at the western entrance to the Bass Strait, roughly midway between Tasmania in the southeast and Victoria in the north (Figure 1). Gold Island, about 60 km north-south, the maximum width of 25 km, the shallow sea ridge stretching from Tasmania north and west. The ridge is between two important Mesozoic-Tertiary sedimentary basins, the Bath Basin to the east and the Otway Basin to the west. These basins formed during the Mesozoic Era due to the tectonic activity associated with the dissolution of the Gondwanaland.