[1] The Coast Ridge Belt (CRB, Santa Lucia Mts., central California) comprises mid-crustal rocks (750–800 C and 0.8 GPa) of the California magmatic arc. We estimated the bulk composition of the CRB and converted our results to seismic velocities expected at the observed pressures and temperatures. The bulk composition of this arc section changes abruptly at 25 km depth from a granodiorite to a ...

[1] Among volcanic hot spots globally, Hawaii has the highest magma flux, yet there is significant controversy surrounding the composition of the mantle sourcing Hawaiian lavas. In order to place constraints on the source lithologies of Hawaiian lavas, we explore relationships between major elements and radiogenic isotopes in tholeiitic, shield-building lavas. Olivine-fractionation corrected la...

[1] Definitive exposures of pristine, ancient crust on Mars are rare, and the finding that much of the ancient Noachian terrain on Mars exhibits evidence of phyllosilicate alteration adds further complexity. We have analyzed high-resolution data from the Mars Reconnaissance Orbiter in the well-exposed Noachian crust surrounding the Isidis basin.We focus on data from the Compact Reconnaissance I...

The composition of the silicate portion of Martian regolith fines indicates derivation of the fines from mafic to ultramafic igneous rocks, probably rich in pyroxene. Rock types similar in chemical and mineralogical composition include terrestrial Archean basalts and certain achondrite meteorites. If these igneous rocks weathered nearly isochemically, the nontronitic clays proposed earlier as a...

The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) investigation, on board the European Space Agency Mars Express mission, is mapping the surface composition of Mars at a 0.3- to 5-kilometer resolution by means of visible-near-infrared hyperspectral reflectance imagery. The data acquired during the first 9 months of the mission already reveal a diverse and complex su...

Lithological, structural, metamorphic and geochronological data for the North China Craton enable its division into the Western and Eastern Blocks of Archean to Paleoproterozoic age separated by a north–south trending Paleoproterozoic orogenic belt: the Central Zone. The Central Zone is divisible into a series of lowto medium-grade granite–greenstone belts and high-grade metamorphic terrains co...

Introduction: The nature, origin and evolution of Mars' Noachian crust is relatively unknown [1]. Detailed analyses of meteorites point to an early differentiation event for the planet but the only rock definitively of Noachian age is the Martian meteorite; ALH84001, comprised of >95% orthopyroxene [2]. Our understanding of the composition of the Martian crust is derived mostly from Amazonian-a...