大陆岩石圈研究进展

从地震学、地球化学、岩石学等不同学科的角度,对大陆岩石圈研究进展做了简要介绍。不同学科的最新研究成果表明,岩石圈在热状态、化学成分和力学行为等方面具有高度非均匀性。这不仅表现为岩石圈性质和结构随深度的变化,而且还反映在不同时代、大陆与海洋以及克拉通和造山带岩石圈结构特征的显著差异上。性质和结构的差异体现了岩石圈形成和长期演化过程的复杂性。我们认为,不同岩石圈块体之间、岩石圈与深部对流地幔之间普遍存在着相互作用。这种相互作用被认为是稳定克拉通岩石圈遭受改造甚至破坏的深部机制,同时还是地球深、浅部物质交换的重要方式,因而显著影响着地球深部的对流和地表的构造过程。值得注意的是,由于岩石圈本身定义的模糊性及其厚度的不确定性,地震活动与岩石圈强度之间的关系以及大陆岩石圈演化的规律性等问题仍有待于进一步的研究和探索。

Progress in continental lithosphere studies

In this paper, recent progress in seismological, geochemical and petrological studies of the continental lithosphere studies are reviewed. These studies indicate that the continental lithosphere is characterized by heterogeneities in its thermal state, chemical composition and mechanical behavior. This is demonstrated not only by the apparent structural variations with depth in the lithosphere, but also by striking structural contrasts between different lithospheric types, including those of different ages, continental versus oceanic, and cratons versus orogens. Such variations in properties further indicate the complexity of the formation processes and evolution of the lithosphere over long geological periods. We consider that the interactions between lithospheric blocks and between the lithosphere and deep mantle occurred frequently in the evolutionary history of the Earth, and these interactions are the mechanisms for the alteration and destruction of some stable cratons. These interactions may also serve as important ways for lithosphere recycling and mass exchange between the shallow and deep parts of the Earth, which could significantly affect deep mantle convection and surface tectonic processes. We need to keep in mind that the relationship between seismicity and lithosphere strength, and the regularity in the evolution of continental lithosphere remain ambiguous and further studies are necessary to resolve issues and problems.