STUDY OF GEOLOGIC CORRELATION BETWEEN SRI LANKA AND ANTARCTICA

在斯里兰卡前寒武纪高级变质岩中，冈瓦纳碎屑之一的一些地质年代学、岩石学和矿物学特征已被发现，这些特征与东南极Syowa站周围的高级变质岩相似。首先，斯里兰卡岩石经历了约1100 Ma的主要区域变质作用，并在花岗岩侵位时局部再变质约500 Ma。其次，在高地系和西南群的岩石中都发现了残留的蓝晶石，这表明最初的高压和低温变质条件。此外，次生红柱石不仅存在于西南群岩中，而且还存在于高地系列岩石中。这些事实表明，高地组和西南群都经历了相似的压力-温度演化，尽管后期的低压变质叠置在西南组比高地组广泛得多。第三，蓝宝石和尖晶石，斯里兰卡的重要宝石，被确定产于白云岩大理石中。

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.