马达加斯加前寒武纪变质基底特征综述

马达加斯加岛是全球重要的前寒武纪变质单元之一,是冈瓦纳大陆重要的组成部分.对其地质调查过程从19世纪初至今主要经历了4个阶段,上世纪90年代至今20几年新理论和新方法的应用使得其基础地质研究得到飞跃发展.根据现有研究,将马达加斯加岛构造单元划分为:太古宙Antongil块体、太古宙-元古宙Antananarivo块体、太古宙Tsaratanana绿岩带、南部元古宙块体和北部新元古宙块体5个部分,每个部分又可进一步细分不同的构造单元.该岛整体上经历中新太古代变质基底形成和新元古代构造活化两个阶段,其中新元古代构造活化与冈瓦纳大陆形成密切相关.

OVERVIEW OF THE PRECAMBRIAN GEOLOGY OF MADAGASCAR

The Madagascar Island, as one of the most important Precambrian metamorphic blocks of the earth, is a significant component of the Gondwana supercontinent. Geological survey in the island has been carried out since the beginning of the 19th Century. In the last 20 years, the applications of new theories and techniques improve the study of fundamental geology. Tectonically, the Madagascar Island can be divided into five units, i.e. the Archean Antongil block, the Archean-Proterozoic Antananarivo block, the Archean Tsaratanana greenstone belt, the southern Proterozoic block and the northern Neoproterozoic block, each of which can be subdivided into different tectonic units. As a whole, Madagascar experienced the Archean basement formation and the Neoproterozoic block activation. The stage of the Neoproterozoic block activation is closely related to the formation of Gondwana supereontinent.