The evolution of continental roots in numerical thermo-chemical mantle convection models including differentiation by partial melting

A characteristics-based method for solving the transport equation and its application to the process of mantle differentiation and continental root growth

“…Previous low-resolution experiments (De Smet et al 1998), in which the resolution was about 10 times coarser in the horizontal direction than the highest resolution used here, still reveal the same diapiric melting events as those presented here within the framework of an upper mantle continental model. The same type of melting phenomenon is found as in the models of De Smet et al (1999).…”

“…In this model the transport equation contains a source term, which describes the melt production in pressure-released partial melting. In this model, a characteristic phenomenon of small-scale melting diapirs is observed (De Smet et al 1998;De Smet et al 1999). High-resolution experiments with grid cells down to 700 m horizontally and 515 m vertically result in highly detailed observations of the diapiric melting phenomenon.…”

Thermal and crustal evolution of Mars

“…The viscous strength of partially molten systems, while a topic of intense interest (review by Kohlstedt and Zimmerman [1996]) may yet be lacking an adequate description that captures effects of a solid-liquid system as well as the dehydration of solids during melting [Hirth and Kohlstedt, 1996]. In addition, numerical work has begun to shed a little light on the dynamics of a system undergoing partial melting [Ogawa, 1993;DeSmet et al, 1999] but has yet to elucidate consequences for the efficiency of the convective system. In the absence of such physical knowledge we are left simply with the option of estimating the purely energetic effects due to the thermodynamics of melting.…”

Geochemistry of late Mesozoic mafic magmatism in west Shandong Province, eastern China: Characterizing the lost lithospheric mantle beneath the North China Block.

“…Gao et al (1998) noted that the thick lithosphere beneath NCB had been rapidly delaminated, followed by emplacement of extensive mafic rocks and voluminous granitic plutons and associated large-scale metal metallogeny. However, numerical modeling shows that a compositionally distinct Archean lithospheric root consisting of depleted peridotite can grow and remain stable during a period of secular cooling, even within a hot convecting mantle due to its intrinsically lower density and temperature-dependent rheology (De Smet et al, 1999). Hence, it is difficult for chemically refractory peridotites with lower density to be destroyed or delaminated unless they have been impacted by an upwelling mantle plume or entrained by lithospheric thickening related to plate subduction or collision which triggers gravitational instability.…”