岩石圈HPE热弱化与陆内构造变形

大陆内部变形在很大程度受制于大陆岩石圈流变侧向不均一性,而温度(地热梯度)是影响地壳和地幔岩石流变性质的主导因素。由热引起的地壳/地幔岩石材料的热弱化是弱化的主要途径,为陆内变形准备了物质条件。在构造外力(板块相关的或非相关的)的作用下,这些受到热弱化的岩石材料极易发生变形,导致岩石圈内部的造山带和变形带的形成。文章试图在广泛的国内外文献搜集和综合分析基础上,介绍由生热元素(heat-producing elements)聚集产生的地壳/地幔(岩石)热弱化以及随后地幔下降流构造力作用造成的大陆内部应变局部化和陆内构造变形。这些地幔下降流是由大陆岩石圈地幔重力(瑞利-泰勒型)不稳定性发育引起的。

Thermal weakening of lithosphere by heat-producing elements and intracontinental deformation

To a large degree,the intracontinental deformation is controlled by lateral rheological heterogeneities of lithosphere,and temperature(thermal gradient) is the major factor affecting the rheology of crust and mantle.The thermal weakening of crust/mantle rocks induced by heat represents a main way in rock weakening,which provides material condition for intracontinental deformation.Under the tectonic forcing(plate-related or non-plate-related),these weakened rock materials are easily deformed and formed orogenic belt and deformation belt at continental interiors.This paper,based on the study of a great deal of relevant publications,introduces the thermal weakening of crust and mantle rocks caused by heat-producing element enrichment in the lithosphere and occurrence of strain localization and intracontinental deformation under the tectonic force produced by mantle downwelling induced by lithospheric mantle gravitational(Rayleigh-Taylor type) instabilities.