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大陆克拉通是地球表面上相对稳定的构造单元。从地热学的角度考虑,克拉通岩石圈的稳定意味着地表热流等于对流地幔岩石圈底部提供的热流加上岩石圈内部由放射性衰变产生的热量。太古代稳定克拉通一般具有冷的地热特征,且处于热平衡状态。打破克拉通热平衡的因素有多种,如岩石圈地幔的放射性生热、来自深部的地幔柱、板块俯冲等。华北是全球古老克拉通遭受破坏最明显和最典型的地区,其破坏与中生代太平洋板块向东亚的深俯冲密切相关。古太平洋板块快速俯冲并停滞在地幔转换带脱水、形成宽约1 000 km的低粘大地幔楔,导致地幔对流增强。在活跃地幔对流的热侵蚀与橄榄岩一熔体相互作用共同作用下,华北克拉通在中生代期间迅速减薄。经过中生代加热减薄的华北克拉通岩石圈强度显著变弱,在俯冲板块后撤作用下,岩石圈拉张并进一步减薄,地表热流升高。华北克拉通破坏是一个漫长的历程,期间大地热流的演化特征呈现出由中生代以前的低值演化至新生代的高值再过渡到现今的中等状态(接近全球大陆平均值)。
Continental craton is a relatively stable tectonic unit on the surface of the earth. From a geothermal point of view, the stability of the cratonic lithosphere means that the surface heat flux is equal to the heat flux provided at the base of the convective mantle lithosphere plus the heat generated by radioactive decay within the lithosphere. Archean stable craton generally has cold geothermal characteristics and is in thermal equilibrium. There are many factors that can break the heat balance of cratons, such as the radiative heat generation in the lithospheric mantle, the mantle plume in the deep, and the plate subduction. North China is the most obvious and typical area of ancient global craton destruction and its destruction is closely related to the deep subduction of the Mesozoic Pacific plate to East Asia. The Paleo-Pacific plate quickly subducted and stagnated in the mantle transition zone to form a low-viscous and large mantle wedge with a width of 1 000 km, resulting in enhanced mantle convection. Under the combined effect of active mantle convection thermal erosion and peridotite-melt interaction, the North China craton thinned rapidly during Mesozoic. The lithospheric strength of North China craton thinned by Mesozoic heat thinning was significantly weakened. Under the retreat of subducted plate, the lithosphere expanded and further thinned, and the surface heat flux increased. The destruction of the North China craton is a long process during which the evolution of the geothermal heat flow shows a transition from the low value of the Mesozoic to the high value of the Cenozoic and then to the present medium state (close to the average of the world continent).