Estimates of the chemical composition of the bulk (entire) Moon fall into two drastically different categories. One group of estimates claims that the Moon is enriched in refractory elements (those that boil at high temperatures, such as calcium and aluminum) by about 50% compared to Earth. The other group claims that the abundances of refractory elements are the same in the Earth and Moon. Two...

A compilation of geochemical data from >50 active volcanoes where seismically defi ned Moho depth measurements are available, representing most volcanic arcs around the world, indicates a relation exists between crustal thickness (Moho depth) and the trace element composition of basalts. The best correlation exists for maximum light/heavy rare earth element (REE) ratios, and we use maximum Ce/Y...

[1] We have used new compositional information on Martian basaltic rocks from the Mars Exploration Rover Spirit and data from new stereo imaging by the High Resolution Stereo Camera (HRSC) on the Mars Express orbiter to constrain an existing analyticalnumerical computer model to assess the potential of Martian lavas to form lava channels by erosion of substrate. The basaltic rocks studied in Gu...

The ratio 3He/4He (R) plays a central role in models of mantle evolution that propose an undegassed lower mantle, rich in the primordial isotope 3He. A large primordial volatile-rich reservoir, a feature of recent models, is inconsistent with high-temperature accretion and with estimates of crustal and bulk Earth chemistry. High R can alternatively reflect high integrated 3He/(U+Th) ratios or l...

The Wadi Hodein area contains a wide variety of late Precambrian igneous and metamorphic rocks, represented by gneisses, serpentinites, metagabbros, metasediments, metavolcanics, metagabbro-diorite, granodiorite and granitoids. The Wadi Hodein metavolcanics (WHV), including G. Khashab and G. El Anbat, represent one of the significant metavolcanic suites in the southern part of the Nubian Shield...

Origin of Lunar Basalts: A Geophysical Interpretation J. Arkani-Hamed Lunar Pyroclastic Soils of the Apollo 17 Double Drive Tube 74001/2 A. Basu, D. S. McKay, and S. J. Wentworth Lunar Explosive Volcanism: The Remote Sensing Perspective C. R. Coombs and B. R. Hawke The Optimal Lunar Resource: Ilmenite-rich Regional Pyroclastic Deposits C. R. Coombs, B. R. Hawke, and B. Clark Pyroclastic Volcani...