STUDY OF GEOLOGIC CORRELATION BETWEEN SRI LANKA AND ANTARCTICA

冈瓦纳古陆残片之一的斯里兰卡前寒武纪高级变质岩，具有与东南极雪瓦站周围高级变质岩相同的年代学、岩石学和矿物学特征。第一，斯里兰卡岩石遭受了主要的区域变质作用。1100 Ma，局部再变质。500 Ma花岗岩侵位。其次，在高地岩系和西南岩群的岩石中都发现了残留蓝晶石，表明变质作用的初始条件是相对高压和低温。此外，还发现次生红柱石不仅出现在西南群岩石中，而且也出现在高地系列岩石中。这些事实表明，高地系和西南群经历了相似的压力-温度演化，尽管西南群后期低压变质叠加作用比高地系广泛得多。第三，斯里兰卡的重要宝石，蓝宝石和尖晶石，被确定出现在花岗岩大理石中。

In the Precambrian high-grade metamophic rocks from Sri Lanka, one of the Gondwana fragments, have been revealed several geochronological, petrological and mineralogical features in common to those of the high-grade metamorphic rocks around Syowa Station, East Antarctica. First, the Sri Lankan rocks suffered main regional metamorphism ca. 1100 Ma, and were remetamorphosed locally ca. 500 Ma when granitic rocks were emplaced. Secondaly, relict kyanite was found to occur in rocks of both the Highland Series and the Southwestern Group, suggesting initial relatively high-pressure and low-temperature conditions of metamorphism. In addition, secondary andalusite was found to occur not only in the Southwestern Group rocks but also in the Highland Series rocks. These facts show that both the Highland Series and the Southwestern Group have experienced similar pressure-temperature evolution, thoug the later low-pressure metamorphic overprinting was much more extensive in the Southwestern Group than in the Highland Series. Thirdly, supphire and spinel, important gems of Sri Lanka, was established to occur in dolomitic marbles.