The amalgamation of continental blocks naturally results in a lithosphere with lateral variations in thickness due to the juxtaposition of thicker cratonic and thinner orogenic lithospheres, which in turn evolve together through time. After the amalgamation, this mosaic of continental blocks can experience longstanding periods of relative tectonic quiescence until the next tectonic event, for instance continental rifting. Using geodynamic numerical models, we explored the internal deformation of the continental lithosphere during periods of tectonic quiescence taking into account lateral variations of lithospheric thickness. We observed that the orientation of lateral flow of the thick cratonic lithosphere depends primarily on the compositional density contrasts (Δρ) between the asthenosphere and continental lithospheric mantle and on the width of the juxtaposed mobile belt lithosphere. In the case of mobile belts wider than 300 km, the margin of the thick craton flows towards (or underplates) the base of the thin lithosphere when Δρ ≥ 32−48 kg/m³, whereas for smaller Δρ values, the thick cratonic margin flows away from mobile belt, preserving a sharp thickness variation. For mobile belts narrower than 300 km, the Δρ threshold between underplate or outward behavior decreases with the mobile belt width. Underplating of cratonic lithosphere beneath the thin lithosphere is efficient in mobile belts narrower than 300 km and for higher Δρ, which allows them to cool, thicken and stiffen. Lateral flow of cratonic lithosphere is not efficient to underplate wide mobile belts thoroughly, so the latter are influenced by asthenospheric heat for prolonged periods and thus remain less rigid. Therefore, we propose that protracted tectonic quiescence of supercontinents can develop lithospheric rheological inheritances that may or may not facilitate post-quiescence continental lithospheric rifting.

大陆块的合并自然会导致岩石圈的厚度发生横向变化，这是由于较厚的克拉通和较薄的造山岩石圈并置造成的，而岩石圈又随时间一起演化。合并后，大陆块的这种马赛克可能经历长期的相对构造静止期，直到下一次构造事件，例如大陆裂谷。利用地球动力学数值模型，我们考虑了岩石圈厚度的横向变化，探讨了构造静止期岩石大陆内部的变形。我们观察到厚克拉通岩石圈的侧向流动方向主要取决于软流圈和大陆岩石圈地幔之间的成分密度对比（Δρ）以及并列的活动带岩石圈的宽度。对于宽于300 km的移动带，当Δρ≥32−48 kg / m时，厚克拉通边缘向薄岩石圈底部流动（或下冲）。³，而对于较小的Δρ值，较厚的克拉通容限从移动带上流走，从而保持了急剧的厚度变化。对于小于300 km的活动带，底板或向外行为之间的Δρ阈值随活动带宽度而减小。在小于300 km的窄带和较高的Δρ的移动带中，克拉通岩石圈的下方镀层是有效的，这使它们能够冷却，变厚和变硬。克拉通岩石圈的侧向流动不能有效地在宽的运动带上充分铺垫，因此后者长期受到软流层热的影响，因此保持较低的刚性。因此，我们提出，超大陆的长期构造静止可以发展岩石圈流变学的遗传，这可能会或可能不会促进静止后的大陆岩石圈裂谷。