Geochemical evidence suggests that the material accreted by the Earth did not change in nature during Earth's accretion, presumably because the inner protoplanetary disc had uniform isotopic composition similar to enstatite chondrites, aubrites and ungrouped achondrite NWA 5363/5400. Enstatite meteorites and the Earth were derived from the same nebular reservoir but diverged in their chemical e...

The Pontlyfni meteorite fell on Coch-y-Bug Farm, Pontlyfni, Llanwnda, Caernarvonshire, Wales at 11 : 53; April 14, 1931 [1]. Most of the mass is believed to have fallen into the sea, but a 150-g stone was seen to fall on land and was recovered. L.J. Spencer was allowed to examine the stone shortly after its fall, but he could only state that it was a meteori te of an unusual type. The meteorite...

S U M M A R Y We develop a self-consistent thermodynamic description of silicate liquids applicable across the entire mantle pressure and temperature regime. The description combines the finite strain free energy expansion with an account of the temperature dependence of liquid properties into a single fundamental relation, while honouring the expected limiting behaviour at large volume and hig...

[1] The concentration and incorporation mechanisms of hydrogen into (Mg, Fe)2SiO4 olivine have been studied under water saturated conditions at 12.5–14.0 GPa and 1100–2000 C. The hydrogen content of olivine (Fo90–Fo95) coexisting with enstatite and hydrous melt increases from about 4600 ppmw at 1100 C to a maximum of 6250 ppmw at 1200 C. Above 1400 C, the hydrogen content of olivine decreases n...

Chondrites stem from undifferentiated asteroidal parent bodies that nevertheless experienced a certain degree of metamorphism after their formation in the early solar system. Maximum temperatures depend mainly on time and abundance main heating source, which is short-lived 26Al (half life 720 000 yr). Enstatite chondrites formed under reducing conditions include many strongly metamorphosed memb...