THE MAGMA OCEAN CONCEPT AND LUNAR EVOLUTION, Page 1 of < Previous page | Next > /docserver/preview/fulltext/earth/13/1/annurev.ea.13.050185.001221-1.gif

KREEP is a lunar material having very high concentrations of incompatible elements; its name an acronym for the incompatibles K, rare‐earth elements (REE), and P. Although few pristine (endogenously igneous) KREEPy samples were returned from Apollo 15 17 sites, most are polymict breccias. Most models petrogenesis have been based on partial melting variety sources. Such fail to explain veritable absence variations in element patterns over sampled portion moon. We defined component average...

Foreword. 1. Introduction. 1.1. Semantic Web Technologies. 1.2. The Goal of the Web. 1.3. Ontologies and Ontology Languages. 1.4. Creating Managing Ontologies. 1.5. Using 1.6. Applications. 1.7. Developing References. 2. Knowledge Discovery for Construction. 2.1. 2.2. Discovery. 2.3. Definition. 2.4. Methodology Semi-automatic 2.5. Learning Scenarios. 2.6. Learning. 2.7. Related Work on 2.8. Discussion Conclusion. Acknowledgments. 3. Annotation Human Language Technology. 3.1. 3.2....

Earth and Moon are shown here to be composed of oxygen isotope reservoirs that indistinguishable, with a difference in {\Delta}"17O -1 +/- 5ppm (2se). Based on these data our new planet formation simulations include realistic model for isotopic reservoirs, results favor vigorous mixing during the giant impact therefore high-energy high- angular-momentum impact. The indicate late veneer impactors had an average within approximately 1 per mil terrestrial value, suggesting were water rich.

Geochemical evidence suggests that the material accreted by Earth did not change in nature during Earth's accretion, presumably because inner protoplanetary disc had uniform isotopic composition similar to enstatite chondrites, aubrites and ungrouped achondrite NWA 5363/5400. Enstatite meteorites were derived from same nebular reservoir but diverged their chemical evolutions, so no chondrite sample meteorite collections is representative of building blocks. The similarity (Δ(17)O, ε(50)Ti...

Abstract— New data for lunar meteorites and a synthesis of literature have significant implications the interpretation global Th Moon's bulk composition. As presently calibrated (Prettyman et al. 2002), Lunar Prospector gamma‐ray imply that average surface = 1.58 μg/g. However, calibration yields implausibly high concentrations three most Th‐poor documented sampling sites, it extrapolates to nonzero Th, ˜0.7 μg/g, at zero sample results in misfit toward too‐high when compared with regolith...

A group of 32 meteorites, the SNC ( S hergotty, N akhla, C hassigny) group, was derived from Mars as a product 4–7 ejection events, probably Tharsis and Elysium–Amazonis. The SNCs either have basaltic mineralogy or some are ultramafic cumulates crystallized melts. can be classified both petrographically geochemically. We classify shergottite meteorites on basis their light rare earth element (LREE) depletion into highly depleted, moderately depleted slightly depleted. samples (which mainly...

Research Article| November 01, 2000 Los Angeles: The most differentiated basaltic martian meteorite Alan E. Rubin; Rubin 1Institute of Geophysics and Planetary Physics, University California, Angeles, California 90095-1567, USA Search for other works by this author on: GSW Google Scholar Paul H. Warren; Warren James P. Greenwood; Greenwood Robert S. Verish; Verish 2P.O. Box 237, Sunland, 91040, Laurie A. Leshin; Leshin 3Department Geology Center Meteorite Studies, Arizona State University,...

The moon is covered by a blanket of porous impact rabble (megaregolith) that probably averages about 2–3 km in thickness, and has thermal conductivity roughly 0.20 W m −1 K , i.e., 13 × lower than the mean lunar lithosphere, 5–10 subjacent anorthositic crust We employ finite difference models to study effects insulation megaregolith on evolution. Results indicate two important influences heat flow: (1) Because exceptionally thin mare regions, passes more readily through them highland even...

The cooling histories, and in particular the core rates, of differentiated asteroids are calculated, employing a variety thermal conductivity structures order to simulate potential insulating effects regolith megaregolith (brecciated impact rubble) layers. is assumed have 0.005×the unbrecciated mantle conductivity, its thickness, our most typical model, be 0.003×the parent body radius. megaregolith, if present, 0.1×that mantle. We find that combination relatively thick can potentially reduce...

The final stage of terrestrial planet formation consists the clean-up residual planetesimals after giant impact phase. Dynamically, a planetesimal population is needed to damp high eccentricities and inclinations planets circular coplanar orbits stage. Geochemically, highly siderophile element (HSE) abundance patterns inferred for Moon suggest that total about 0.01 M⊕ chondritic material was delivered as "late veneer" by end impacts. Here, we combine these two independent lines evidence...

The lunar magma ocean (or magmasphere) hypothesis, always controversial, has required considerable revision in recent years. geochemical bimodality of pristine rocks, epitomized by a diagram Na/(Na + Ca) versus mg′ ratio, led to proposals that major fraction the crust (the Mg‐rich suite) formed as cumulates numerous intrusions slightly younger than magmasphere. precise origin been elusive, however. One previous suggestion was Na lost volatile before ferroan anorthosites crystallized from...