Search

Carbon-dioxide-rich kimberlitic melt explains the low velocity and high electrical conductivity of the mantle asthenosphere and controls the flux of incompatible elements at oceanic ridges.

Carbon cycling in the mantle may be a common mechanism that links the Great Oxidation Event and the subsequent Lomagundi increase in carbon isotope values, according to a box model that accounts for carbon and oxygen fluxes and reservoirs.

The planetary architecture of the Solar System and its isotopic dichotomy can be reproduced using a protoplanetary disk model structured with rings and gaps, as commonly seen in protoplanetary disks around other stars.

The carbon abundance in the Earth’s mantle is enhanced relative to sulfur. Experiments suggest that the accretion of a differentiated planetary body to the growing Earth could explain the silicate Earth’s carbon and sulfur budgets.

Little is known about the deep carbon cycle during the Archaean. High- pressure and -temperature experiments indicate that the subduction of organic carbon on a hotter, younger Earth was efficient, helping to sequester carbon in Earth’s interior.

Here it is shown that the ratio of zinc to total iron content constrains the valence state of iron in primary arc basalts and their mantle sources. Primitive arc magmas have identical Zn/Fe_T ratios (Fe_T = Fe²⁺ + Fe³⁺) as mid-ocean-ridge basalts, indicating a similar iron oxidation state of primary mantle melts in arcs and ridges and that the subduction of oxidized crustal material may not significantly alter the redox state of the mantle wedge. It is concluded that the observed higher oxidation states of arc lavas must therefore be, in part, a consequence of shallow-level differentiation processes.

By determining the solidus of carbonated peridotite at high pressure it was demonstrated that melting beneath mid-ocean ridges may occur at greater depths than usually assumed — down to 330 kilometres or more.

Correlation between large igneous province activity and iron formation ages suggests that subducted iron formations may have facilitated mantle plume upwelling in the Archaean and Proterozoic Earth.

Rates of protoplanetary accretion and differentiation control the depletion of nitrogen in rocky planets, according to high-pressure/temperature experiments that show that nitrogen is extremely siderophilic.

The resonant chain of the TRAPPIST-1 planets is dynamically fragile, as small perturbations during its lifetime would have disrupted it. N-body simulations show that the system could not have interacted with more than 0.05 Earth masses of material after its formation. Thus, any water in the planets must come from the planets’ original accretion.

Studies of iron meteorites show that volatile nitrogen originated in three isotopically distinct reservoirs in the early Solar System: the nebular gas, sampled by the Sun and Jupiter, and two others related to organic molecules and dust in the inner and outer Solar System, from which growing protoplanets incorporated nitrogen.

For the first billion years or so of the Earth's history, there may have been whole-mantle convection, but after this period differentiation of the Earth's mantle has been controlled by solid-state convection. Many trace elements — known as 'incompatible elements' — preferentially partition into low-density melts and are concentrated into the crust, but half of these incompatible elements should be hidden in the Earth's interior. It is now suggested that a by-product of whole-mantle convection is deep and hot melting, resulting in the generation of dense liquids that sank into the lower mantle.

A carbon content in Earth’s outer core between 0.3 and 2.0 % by weight, along with at least two other light elements, is compatible with observational constraints, according to molecular dynamics simulations, and could make the core Earth’s largest carbon reservoir.