北阿平宁蛇绿岩和西阿尔卑斯高压变质带——访意大利考察报告

THE NORTH APENNINE OPHIOLITES AND THE HIGH PRESSURE METAMORPHIC BELT IN THE WESTERN ALPS( A Geological Report about the Visit to Italy)

本文记叙了北阿于宁蛇绿岩所特有的岩石序列、形成和就位时代、洋底交质、造山变质和弗罗伦萨学者们对北阿平宁蛇绿岩成因的新见解:即转换断层产生的蛇绿岩.西阿尔卑斯与北阿平宁实为一体,但它在始阿尔卑斯发生了榴辉岩相变质.最近都灵大学的R.库潘尼奥尼发现了柯石芙及白片岩组合.本文记叙了Sesia带榴辉岩组合特点、温压条件和高压变质带的发育与欧亚板块、非洲板块碰撞的关系.最后作者提出三点改进我们研究工作的建议.

The present article describes the special rock sequence developed, the age of the ophiolites and their emplacement, the ocean floor metamorphism, the orogenic metamorphism and the new model for the origin of the north Apennine ophiolites proposed by the geologists in Florence. In fact, the western Alps and the north Apennine are in the same belt, but in western Alps eclogitic metamorphism is widely spread. Coesite and white schist mineral assemblages have been found in recent years. The present paper describes the high pressure rock association in Sesia Zone, the pt conditions prevailing in eclogitic metamorphism and the development of HP metamorphism in relation to the collision between the Eurasia and the African plates. In conclusion three proposals have been made for the improvement of the domestic research work.