Craton Destruction Induced by Drastic Drops in Lithospheric Mantle Viscosity

Abstract The disruption of the mantle roots cratons is common after cratonization. Craton destruction, which characterized by severe lithospheric thinning, extensive thrust and extensional deformation, basin filling, intense thermal activities, relatively rare generally attributed to intensely reduced viscosity contrasts between root underlying asthenosphere. However, extent required contrast remains unclear. North China craton (NCC) a typical example partially destroyed craton, with its eastern part experiencing destruction in Early Cretaceous. In this study, we measured water content clinopyroxene phenocrysts Middle Jurassic mantle‐derived, weakly alkaline volcanic rocks from Shanhaiguan area. Our data those previous studies show that NCC contained substantial amounts (650–2,900 ppm) before destruction. addition, continuous supply subducted Paleo‐Pacific slab resulted more hydrous (up ca. 9,000 during asthenosphere (with an average 3.7 × 10 18 Pa s) were 2–8 0.3–2 respectively. study indicates drastic drop viscosity, controlled synergic effects high elevated temperature, induce