第32届国际地质大会造山带和蛇绿岩研究进展

第32届国际地质大会反映了近年来造山带和蛇绿岩研究的最新成果。太古代与年轻造山带对比研究表明决定造山带几何特征的主要因素是它们与同造山及造山期后的伸展构造体制的响应方式。进一步分析了中新元古代罗得利亚超大陆的形成与裂解机理。分析了晚前寒武纪—古生代造山作用过程及可能模式。造山带形成后其深部表露、抬升和剥蚀过程与气候及环境演变有紧密的关系,是当前及今后地球科学的重要研究领域。蛇绿岩的岩浆成因并不能用一种简单的模式来解释,研究表明蛇绿岩岩浆具多成因。提出了蛇绿岩套的双离散侵位模式、多米诺旋转侵位模式、俯冲快速折返就位模式。对比表明特提斯及环太平洋蛇绿岩的来源、演化及就位特征具明显的多样性。

ADVANCES IN OREGENIC BELTS AND OPHIOLITES IN THE 32ND INTERNATIONAL GEOLOGICAL CONGRESS

There are a whole series of recent achievements about oregenic belts and ophiolites presented in the 32nd International Geological Congress. A comparative study of Archean and younger orogens lead to a conclusion that the key factor in determining these orogens' overall geometries is the way how they respond to the process of syn- to post-orogenic extensional tectonism. Mechanism of Rodinia supra-continent about Mesoproterozoic assembly and Neoproterozoic breakup is further discussed. Oregenic process and possible model during late pre-Cambrian period and Paleozoic were analyzed. Deep exhumation, uplift and denudation of oregens are closely related to changes of weather and environment evolution, which is an important geological field. Igneous petrogenesis of ophiolites can not be explained by a simple model. It is studied that igneous petrogenesis of ophiolites are multi-genesis. Recent studies also set up several ophiolite emplacement models, such as bidivergent emplacement, domino-like rotation emplacement and subduction and rapid exhumation emplacement. Ophiolites occurred in Tethys and circum Pacific Ocean display obvious variety.