Many studies exist on magmatic volatiles (H, C, N, F, S, Cl) in and on the Moon, within the last several years, that have cast into question the post-Apollo view of lunar formation, the distribution and sources of volatiles in the Earth-Moon system, and the thermal and magmatic evolution of the Moon. However, these recent observations are not the first data on lunar volatiles. When Apollo sampl...

This study investigates petrology and major, minor, and rare earth elements ‎geochemistry of ‎East Iranian Eocene–Oligocene volcanic rocks in Sistan suture ‎zone, to examine their ‎petrogenesis and magma evolution. The volcanic rocks include andesite, trachy-andesite, dacite ‎and rhyolite. ‎These calc-alkaline rocks of high-K series are enriched in Large ‎Ion Lithophile ‎Elements of Rb and Ba a...

Introduction: Chondrites have been used to ascertain the Earth abundances of all but the most volatile elements. Of these, H abundance has dramatic ramifications for the properties of the planet, including rheology and melting relations of the mantle and density and phase relations in the core, yet is poorly known. The very mechanisms of formation of Earth and degassing history depend on the am...

The effects of compositional discontinuities of density and viscosity in the Earth's mantle on the ascent of mantle plume heads is studied using a boundary integral numerical technique. Three specific problems are considered: (1) a plume head rising away from a deformable interface, (2) a plume head passing through an.interface, and (3) a plume head approaching the surface of the Earth. For the...

Both geophysical and geochemical techniques contribute to our understanding of the complex nature of the Earth’s mantle, but the two sources of information provide very different viewpoints. Most geophysical evidence provides an instantaneous snapshot of current structure, whilst geochemical evidence has much more information on age. Further, geophysical probes are naturally integrative since t...

Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacit...

The Earth—and the other terrestrial planets—are differentiated bodies, a metallic core overlain by a sili­ cate mantle. But the nebula from which these planets ultimately formed originally consisted mainly of undif­ ferentiated dust grains. The aim of this chapter is to review how and when the process of differentiation is thought to have taken place. In the first half of this chapter we focus ...

New geochemical data for Pleistocene magmatic rocks from the Surigao peninsula, eastern Mindanao, the Philippines, demonstrate typical adakitic traits, including elevation of Sr /Y and depletion of the heavy rare earth elements. Sr / Sr and Nd / Nd ratios of the adakites do not support melting of the subducted Philippine Sea Plate but resemble Pliocene arc lavas generated in the same subduction...

The Earth's engine is driven by unknown proportions of primordial energy and heat produced in radioactive decay. Unfortunately, competing models of Earth's composition reveal an order of magnitude uncertainty in the amount of radiogenic power driving mantle dynamics. Recent measurements of the Earth's flux of geoneutrinos, electron antineutrinos from terrestrial natural radioactivity, reveal th...

[1] Deformation and texture formation in (Mg, Fe)SiO3 post perovskite (ppv) is a potential explanation for the strong seismic anisotropy that is found in the D00 layer of the Earth. However, different experimental approaches have resulted in different lattice preferred orientations (LPO) in deformed ppv that have led to ambiguity in the interpretation of deformation in the lowermost mantle. Her...