The statistical correlation between the locations of hot spots at the surface of Earth and the distribution of ultra-low-velocity zones at the base of the mantle has about a 1 percent chance of arising randomly. This correlation is more significant than that between hot spots and negative velocity anomalies in tomographic models of deep mantle compressional and shear velocity. This correlation ...

A simplified model of earth structure based on the Nd and Sr isotopic characteristics of oceanic and continental tholeiitic flood basalts is presented, taking into account the motion of crustal plates and a chemical balance for trace elements. The resulting structure that is inferred consists of a lower mantle that is still essentially undifferentiated, overlain by an upper mantle that is the r...

Elastic anisotropy is present where the speed of a seismic wave depends on its direction. In Earth's mantle, elastic anisotropy is induced by minerals that are preferentially oriented in a directional flow or deformation. Earthquakes generate two seismic wave types: compressional (P) and shear (S) waves, whose coupling in anisotropic rocks leads to scattering, birefringence, and waves with hybr...

The effect of volatde exchange between surface reservoirs and the mantle on the evolution of proto-CO 2 atmosphere on the Earth is investigated using a global carbon cycle model coupled with thermal evolution of the mantle. Carbon is assumed to circulate among five reservoirs (atmosphere, ocean, continents, seafloor and mantle) and the carbon flux of each reservoir is calculated under varying c...

Introduction: Preliminary investigations by these authors concerning the comparison and contrast of characteristics associated with terrestrial layered mafic intrusives (LMI's) and Venusian coronae indicate some similarities in morphology and possibly origin. Our premise is that coronae, and processes related to their formation, may not be unique to Venus and that mantle plumes could have been ...

We use hydrodynamic modelling combined with known data on mantle melting behaviour to examine the potential for decompression melting of lithosphere beneath a large terrestrial impact crater. This mechanism may generate sufficient quantity of melt to auto-obliterate the crater. Melting would initiate almost instantaneously, but the effects of such massive mantle melting may trigger long-lived m...

Mantle convection is vital to our Earth system. The relentless deformation produced inside the Earth's mantle by slow, viscous creep has a far greater impact on our planet than might be immediately evident. Continuously reshaping the Earth's surface, mantle convection provides the enormous driving forces necessary to support large-scale horizontal motion in the form of plate tectonics and the a...

Iron excess of the Earth. The Fe/Mg ratio of the whole Earth is at least 10% higher than the Fe/Mg ratio of the average solar system. Improved estimates of the chemical composition of the primitive upper mantle yield an MgO content of 36.33 ± 0.4 wt% [1], which transforms into a whole Earth Mg content of 14.90 wt%, assuming 32% for the mass of the core and that the core is Mg-free. The FeO cont...