[1] Mountain building at convergent margins requires tectonic forces that can overcome frictional resistance along large-scale thrust faults and support the gravitational potential energy stored within the thickened crust of the orogen. A general, dynamic model for this process is still lacking. Here we propose that mountain belts can be classified between two end-members. First, those of “slab...

The potential effects of continental crust on mantle convection are explored using threedimensional numerical simulations. The simulations model the coupling between a thin, deformable layer of chemically buoyant crust and a deep layer of thermally convecting and chemically dense mantle. Simulations begin with a crustal layer embedded within the upper thermal boundary layer of a mantle convecti...

Numerical simulations in both twoand three-dimensions are performed to investigate the hypothesis that D” is a thermo-chemical boundary layer. A layer of dense, compositionally-distinct material above the CMB reduces the characteristic horizontal lengthscales and interior mantle temperature. In three-dimensions, the layer forms a spoke pattern, with entrainment in upwelling cylinders, even for ...

[1] Compositionally layered mantle models have often been invoked in order to explain the geochemistry observed at the Earth’s surface, specifically the discrepancy between ocean island basalt and mid-ocean ridge basalt compositions. One disadvantage of layered models is the reduction in cooling efficiency compared to whole-mantle convection as a direct result of the insulating nature of the th...

The four most recent large mass extinction events in the Phanerozoic – the Cretaceous–Tertiary (KT), the Triassic–Jurassic (TJ), and the Permo-Triassic (PT) and Guadalupian–Tatarian (GT) doublet – are associated with a major flood basalt eruption, with the timing of peak volcanic activity corresponding within measurement uncertainties to the extinction event. Three magnetic superchrons precede ...

Abstract Carbonate melts have been proposed to exist in the lower mantle, but their interaction with other mantle melt compositions is poorly understood. To understand miscibility carbonate‐silicate‐metal system, we simulate endmember, binary, and ternary mixtures study how Gibbs free energies of mixing evolve pressure. We find that carbonate‐metal carbonate‐silicate gaps close increasing press...

Using a semiempirical approach, we show that modified gravity affects the internal properties of terrestrial planets, such as their physical characteristics core, mantle, and core–mantle boundary. We also apply these findings for modeling two-layer exoplanet in Palatini f(R) gravity.

The boundary between the rocky mantle and iron core, almost 2900 km below the surface, is physically the most significant in the Earth's interior. It may be the terminus for subducted surface material, the source of mantle plumes and a control on the Earth's magnetic field. Its properties also have profound significance for the thermochemical and dynamic evolution of the solid Earth. Evidence f...