Sr, Nd and Pb isotope data for basalts from spreading axes and off-axis volcanoes near the Pacific–Antarctic risecrest, from Vacquier transform to just south of Udintsev transform, reveal an isotopically heterogeneous upper mantle. The Ž . isotopic composition of the mantle is represented by three end-members: 1 the ‘depleted’ source of the bulk of Pacific Ž . Ž . normal-type mid-ocean ridge ba...

Northwest Africa (NWA) 4898 is the only low-Ti, high-Al basaltic lunar meteorite yet recognized. It predominantly consists of pyroxene (53.8 vol%) and plagioclase (38.6 vol %). Pyroxene has a wide range of compositions (En12–62Fs25–62Wo11–36), which display a continuous trend from Mg-rich cores toward Ca-rich mantles and then to Fe-rich rims. Plagioclase has relatively restricted compositions (...

Newly determined ilmenite-melt and orthopyroxene-melt partition coefficients are used to construct quantitative forward models of the evolution of high field strength element (HFSE, Zr, Nb, Hf, Ta, Th, U) and rare earth element (REE: Nd, Sm, Lu) concentrations during crystallisation and subsequent remelting of the Lunar Magma Ocean (LMO). Crystallisation models suggest that the initial LMO must...

Introduction: Mare Moscoviense is an enigma in many ways. Located within some of the thickest crust (80 km [1]) and at ~4 km above the mean lunar radius [2], these basalts were able to overcome buoyancy forces that have been proposed to impede the eruption of farside basalts [3]. In contrast, South Pole-Aitken basin exists in an area of the thinnest crust and 4-6 km below the mean lunar radius;...

Magma genesis, migration, and eruption have played prominent roles in the chemical differentiation of the Earth. Plate tectonics has provided the framework of tectonic environments for different suites of igneous rocks and the dynamic mechanisms for moving masses of rock into melting regions. Petrology is rooted in geophysics. Petrological and geophysical processes are calibrated by the phase e...