岩石圈流变学研究进展

ADVANCES OF RESEARCH ON RHEOLOGY OF THE LITHOSPHERE

岩石圈流变学的目标是研究岩石圈物质的变形、流动及其机制。７０年代以来高温高压岩石力学实验和地热研究的丰硕成果，推动了该分支学科的进展。Ｒａｎａｌｉ等（１９８７）建立了７种岩石圈流变学剖面，并论述了岩石圈的流变学分层特性。此后，一些学者对不同地区的岩石圈做了研究，获得了类似的结果，建立了岩石圈流变学分层理论。运用这一理论，能解释地球科学许多分支学科所研究的不同尺度的构造现象。因为岩石圈的结构分层和流变性质，控制了大陆构造的形成演化，尤其是大陆构造变形。最新研究表明，一系列深成构造作用，如下地壳韧性剪切、造山带演化晚期或造山期后重力塌陷和莫霍面松驰等，与下地壳软化和塑性流动密切相关，而中上地壳（或汇聚带上地幔最上部）脆性域控制了地震震源的分布。

The objective of lithosphere rheology is to study deformation, flow and their mechanisms of lithospheric materials. With the rich results of the experimental rock mechanics under high temperature and high pressure and of geothermal study, this research field has made great progress since 1970′s. The significant advance was that Ranalli et al. (1987) constructed 7 lithospheric rheological profiles and expouded the properties of lithospheric rheological stratification and other scientists have achieved the similar results for different regions ever since. As a result, the theory of lithospheric rheological stratification has come into being. The tectonic phenomena of different scale studied in many subdisciplines of geoscience may be interpreted by applying this theory. Lithospheric structural stratificantion and rheological properties control the formation and evolution, especially deformation of continental tectonics. The studies of recent years have indicated that a series of plutonic tectonic actions, such as ductile shear of lower crust, gravitational collapse and relaxation of Moho topography in the late and post orogenic evolution of mountain belts, correlate closely with softening and plastic flow of lower crust while the brittle regime of mid upper crust or uppermost mantle in the convergent belt controls the distribution of earthquake foci.