Volcanism provides an important mechanism for transferring heat and matter (including volatiles and nutrient elements) from the Earth's interior to its surface reservoirs (Mather, 2015). Studies on the linkage between large igneous provinces (LIPs) and mass extinction events have shown that the volatiles, such as F, Cl, and S, released by giant magmatic events can have strong global-scale effects on the biotic, environmental, and climatic evolution (Callegaro et al., 2014;Oppenheimer et al., 2014;Sobolev et al., 2011). However, what are the effects of less extensive continental magmatism on the evolutionary history of regional biota remain largely unconstrained. Climate-modifying volcanic gases (CO 2 , SO 2 , and halogens) may cause biota poisoning, environmental acidification, ozone depletion, and climatic warming or cooling (Ernst & Youbi, 2017). In contrast, nutrients (e.g., P, Fe)

The disruption of the mantle roots of cratons is common after cratonization. Craton destruction, which is characterized by severe lithospheric thinning, extensive thrust and extensional deformation, basin filling, and intense thermal activities, is relatively rare and is generally attributed to intensely reduced viscosity contrasts between the lithospheric mantle root and the underlying asthenosphere. However, the extent of the required viscosity contrast remains unclear. The North China craton (NCC) is a typical example of a partially destroyed craton, with its eastern part experiencing destruction in the Early Cretaceous. In this study, we measured the water content of clinopyroxene phenocrysts in Middle Jurassic lithospheric mantle‐derived, weakly alkaline volcanic rocks from the Shanhaiguan area. Our data and those of previous studies show that the lithospheric mantle in the eastern NCC contained substantial amounts of water (650–2,900 ppm) before craton destruction. In addition, the continuous supply of water by the subducted Paleo‐Pacific slab resulted in a more hydrous lithospheric mantle (up to ca. 9,000 ppm) during the craton destruction. The viscosity contrasts between the lithospheric mantle root and the asthenosphere (with an average viscosity of 3.7 × 1018 Pa s) were 2–8 and 0.3–2 before and during the craton destruction, respectively. Our study indicates that a drastic drop in the lithospheric mantle viscosity, which is controlled by the synergic effects of a high water content and elevated temperature, is required to induce craton destruction.

Volcanism provides an important mechanism for transferring heat and matter (including volatiles and nutrient elements) from the Earth's interior to its surface reservoirs (Mather, 2015). Studies on the linkage between large igneous provinces (LIPs) and mass extinction events have shown that the volatiles, such as F, Cl, and S, released by giant magmatic events can have strong global-scale effects on the biotic, environmental, and climatic evolution (Callegaro et al., 2014;Oppenheimer et al., 2014;Sobolev et al., 2011). However, what are the effects of less extensive continental magmatism on the evolutionary history of regional biota remain largely unconstrained. Climate-modifying volcanic gases (CO 2 , SO 2 , and halogens) may cause biota poisoning, environmental acidification, ozone depletion, and climatic warming or cooling (Ernst & Youbi, 2017). In contrast, nutrients (e.g., P, Fe)