Peridotite xenoliths in arc volcanoes are very rare, usually small and remain poorly studied. Much of the earlier work focused on peridotites affected by re-crystallization, metasomatism and veining that took place shortly before the eruption of the host magmas; such lithologies may not be widespread in the mantle wedge.This study reports petrographic, major and trace element data for 17 large,...

The composition of continental subduction-zone fluids varies dramatically from dilute aqueous solutions at subsolidus conditions to hydrous silicate melts at supersolidus conditions, with variable concentrations of fluid-mobile incompatible trace elements. At ultrahigh-pressure (UHP) metamorphic conditions, supercritical fluids may occur with variable compositions. The water component of these ...

Mineral inclusions in pyrope crystals from Garnet Ridge in the Navajo Volcanic Field on the Colorado Plateau are investigated in this study with emphasis on the oxide minerals. Each pyrope crystal is roughly uniform in composition except for di€usion halos surrounding some inclusions. The pyrope crystals have near constant Ca:Fe:Mg ratios, 0.3 to 5.7 wt% Cr2O3, and 20 to 220 ppm H2O. Thermobaro...

Chemical weathering indices (one-dimensional/1D index values) and accompanying ternary plots (two-dimensional/2D compositional space) facilitate quantitative comparison of whole-rock mineral major-element data, empirical chemical trends with predicted vectors. However, data analysis in is restricted by poles grouping elements that are hosted different minerals or influenced selectively later al...

Abstract Whiteschists from the Monte Rosa Nappe were examined in field as well with petrographic, geochemical, and isotopic methods to constrain controversial origin of these rocks their Alpine metamorphic context. occur ellipsoidal-shaped, decametric-sized bodies, within a Permian metagranite, consist mainly chloritoid, talc, phengite, quartz. The transition whiteschist metagranite is marked b...