超高压变质岩的全球分布与地球演化节律

高压、超高压变质作用不是一个局部的孤立的地质现象，而是一个时空跨度大、范围广、影响构造观的重要科学问题。文中讨论了世界上三类（１３个）典型超高压变质地区的地质学岩石学特点，从全球构造的角度研讨了超高压变质的时空分布，从而得到下列认识：（１）所有高压、超高压变质岩均分布于全球活动带及其次级褶皱带内，超高压变质岩常常保存于多期变质和变形的基底片麻岩块体中，与深位壳型剪切带关系密切。（２）现有的年代学资料说明大部分超高压变质带出现于显生宙不同时代的褶皱带（造山带）内。（３）超高压变质演化的多阶段性，说明了地球从收缩到膨胀的节律现象。（４）从欧亚大陆范围看来，从北而南，从陆到洋超高压变质有逐渐变新的趋势，可能说明欧亚大陆从中生代以来，有从大陆向大洋方向增生的总趋势。

THE GLOBAL DISTRIBUTION OF ULTRAHIGH PRESSURE METAMORPHIC ROCKS AND ITS IMPLICATION IN THE RHYTHMS OF EARTH′S EVOLUTION

The high pressure (HP) and ultrahigh pressure (UHP) metamorphism is not an occasional or local geological event in the geological history, its large range of distribution in space and time implies its importance in the forming of a current tectonic view in geoscience. In light of the rhythm of the earth evolution, three kinds (13 localities) of typical ultrahigh pressure metamorphic domains are discussed and the global distribution of the UHP rocks are investigated in the present paper. It comes to the author that: (1) All of the UHP metamorphic rocks are distributed along the globally mobile belts or its second order tectonic belts. The UHP metamorphic rocks are mostly preserved in the polymetamorphic and multi stage deformational basement gneiss complex and are closely related to the deep seated crustal shear zones; (2) According to the available geochronological data, most of the UHP metamorphic belts were formed in the Phanerozoic Era in fold belts or orogens of different ages; (3) The multi stage evolution of the UHP metamorphism illustrates the rhythmic evolution of the Earth; (4) In Eurasia from north to south, from inland to oceanwards the age of the HP and UHP metamorphic belts is younging with time. It probably implies that the Eurasian continent has been growing oceanwards since the Mesozoic time.