Aluminium, the third most abundant element in the earth’s crust, occurs in nature in combination with silicon and oxygen (i.e. as aluminium silicate). When subject to tropical weathering, aluminium silicate may react to form aluminium hydroxide. Rock containing high concentrations of aluminium hydroxide is called bauxite. This rock is the usual starting material for the production of aluminium....

Observations and models of Ceres suggest that its evolution was shaped by interactions between liquid water and silicate rock. Hydrothermal processes in a heated core require both fractured rock and liquid. Using a new core cracking model coupled to a thermal evolution code, we find volumes of fractured rock always large enough for significant interaction to occur. Therefore, liquid persistence...

The East Lau Spreading Center (ELSC) and Valu Fa Ridge (VFR) comprise a ridge segment in the southwest Pacific Ocean where rapid transitions in the underlying mantle chemistry manifest themselves as gradients in seafloor rock geochemistry. We studied the geology and microbial diversity of three silicate rock samples and three inactive sulfide chimney samples collected, from north to south, at t...

We examine the possible extent of melting in rock-iron super-earths, focusing on those in the habitable zone. We consider the energetics of accretion and core formation, the timescale of cooling and its dependence on viscosity and partial melting, thermal regulation via the temperature dependence of viscosity, and the melting curves of rock and iron components at the ultra-high pressures charac...

Forested ecosystems diversified more than 350 Ma to become major engines of continental silicate weathering, regulating the Earth's atmospheric carbon dioxide concentration by driving calcium export into ocean carbonates. Our field experiments with mature trees demonstrate intensification of this weathering engine as tree lineages diversified in concert with their symbiotic mycorrhizal fungi. P...

The iron-titanium oxide minerals of three troctolites from the Freetown layered gabbro have been analysed using an electron microprobe. Comparisons of the analyses of the iron-titanium minerals with the data of Buddington and Lindsley (I964) provide temperature and oxygen fugacity information relating to particular magnetite-ilmenite grains. Magnetite-ilmenite grains occurring in different sili...

Global silicate weathering drives long-time-scale fluctuations in atmospheric CO(2). While tectonics, climate, and rock-type influence silicate weathering, it is unclear how these factors combine to drive global rates. Here, we explore whether local erosion rates, GCM-derived dust fluxes, temperature, and water balance can capture global variation in silicate weathering. Our spatially explicit ...

BACKGROUND In aerodynamic levitation, solids and liquids are floated in a vertical gas stream. In combination with CO2-laser heating, containerless melting at high temperature of oxides and silicates is possible. We apply aerodynamic levitation to bulk rocks in preparation for microchemical analyses, and for evaporation and reduction experiments. RESULTS Liquid silicate droplets (~2 mm) were ...

Introduction: The discovery of spinel rich rock on the Earth’s Moon, detected by the M near-IR mapping spectrometer on the Chandrayaan-1 spacecraft [1] is among the most intriguing discoveries in a time filled with lunar revelations (e.g., [2]). The M spectrometer discerned several areas on the rim of the far-side Moscoviense basin which had near-IR reflectance spectra characteristic of abundan...

Basalt: Volcanic lava rock containing silicate minerals rich in magnesium and iron plus plagioclase. CI or chrondritic standard: elemental and isotopic abundances in the sun and in carbonaceous chrondrites are the same except in some very special details. Differentiation: creation of chemical differences in magma by processes that separate minerals from it, usually as a result of contrasting de...