Key Points: 13 • Mantle flow leads to inwardly convergent tractions around the edges of cratons, 14 and compressive stresses within. 15 • Convergent tractions result from the downward diversion of mantle flow. 16 • This convective self-compression could help stabilize older lithosphere against con-17 vective erosion. Abstract 19 Despite being exposed to convective stresses for much of the Earth's history, cratonic roots 20 appear capable of resisting mantle shearing. This tectonic stability can be attributed to 21 the neutral density and higher strength of cratons. However, the excess thickness of cra-22 tons and their higher viscosity amplify coupling to underlying mantle flow, which could 23 be destabilizing. To investigate the stresses that a convecting mantle exerts on cratons 24 that are both strong and thick, we developed instantaneous global spherical numerical 25 models that incorporate present-day geoemetry of cratons within active mantle flow. Our 26 results show that mantle flow is diverted downward beneath thick and viscous cratonic 27 roots, giving rise to a ring of elevated and inwardly-convergent tractions along a craton's 28 periphery. These tractions induce regional compressive stress regimes within cratonic in-29 teriors. Such compression could serve to stabilize older continental lithosphere against 30 mantle shearing, thus adding an additional factor that promotes cratonic longevity. 31 Plain Language Summary 32 Cratons are the oldest continental relicts on Earth. Due to plate tectonics and man-33 tle convection, many non-cratonic rocks get recycled. However, cratons have escaped tec-34 tonic recycling, and some have remained stable for more than ∼ 3 billion years. Previ-35 ous studies have shown that cratons' high strength and neutral buoyancy provide them 36 with tectonic stability. Here we show that the deep roots of cratons also help to stabi-37 lize them. This is because mantle flow is deflected downward beneath thick cratonic roots, 38 and this deflection generates a ring of inwardly-directed forces around the edges of the 39 craton. These inward forces compress the craton interior. Such self-induced compressive 40 stresses may further help to stabilize Earth's oldest lithosphere. 41

In this study, we develop two dimensional (2-D) box models to identify the most viable reasons for the destruction of the North China Craton (NCC). We examine the role of flat slab-induced hydration, high-density lower crust, and weak mid-lithospheric discontinuity in our models. Results indicate that flat slab-induced hydration weakening of the eastern part of the NCC can lead to rapid craton destruction if hydration weakening rates are sufficiently fast. This accelerated hydration rate may be attributed to the extensive carbonatite magmatism within the eastern part of the NCC, facilitating a faster pathway for water diffusion throughout the craton. Craton destruction is contingent upon the craton’s density exceeding the surrounding mantle density, and its viscosity decreasing below 1022 Pa s. We observe that the presence of a dense lower crust or a weak mid-lithospheric discontinuity fail to destroy the NCC unless it is weakened.