Clinopyroxene on the join CaMgSi2O6-CaFe3+AlSiO6-CaTiAl2O6 at low oxygen fugacity

Fe-Ti Oxide Minerals Geothermometry and Oxygen Fugacity at the Dar Gaz Anomaly, Kahnuj

In the southeast of Iran, titaniferous magnetite deposits associated with the gabbro rocks occur in Kahnuj ophiolitic complex. Mineraloghraphy studies have revealed the primary and secondary ore mineral consist of titanomagnetite, ilmenite, hematite, goethite, martite, pyrite, chalcopyrite, pyrrhotite and silicate minerals (plagioclase, pyroxene, hornblende, olivine, alkali feldspar). Trellis-s...

Estimates of Oxygen Fugacity in the Basaltic Shergottites from Electron Microprobe Oxygen Analysis

Oxygen Fugacity at High Pressure: Equations of State of Metal-oxide Pairs. A

Introduction: Oxygen fugacity (fO 2) varies by orders of magnitude in nature, and can induce profound changes in the chemical state of a substance, and also in the chemical equilibrium of multicomponent systems. One prominent area in high pressure geochemistry, in which fO 2 is widely recognized as a principal controlling factor, is that of metal-silicate partitioning of siderophile trace eleme...

The Aurora volcanic field, California-Nevada: oxygen fugacity constraints on the development of andesitic magma

The Aurora volcanic field, located along the northeastern margin of Mono Lake in the Western Great Basin, has erupted a diverse suite of high-K and shoshonitic lava types, with 48 to 76 wt% SiO2, over the last 3.6 million years. There is no correlation between the age and composition of the lavas. Three-quarters of the volcanic field consists of evolved (,4 wt% MgO) basaltic andesite and andesi...

On the Controls of Oxygen Fugacity in the Generation and Crystallization of Peralkaline Melts

The formation of peralkaline melts is generally recognized to be related to enrichment of the mantle in sodium or potassium during a metasomatic event that predated magma generation. The wide range in mineral assemblages, mineral compositions, and fluid compositions in peralkaline melts are, to a large extent, a function of the sodium/potassium content of these mantle-metasomatizing fluids, whi...