Porphyry deposits are large, low-grade metal ore bodies that are formed from hydrothermal
fluids derived from an underlying magma reservoir. They are important as major sources of …

Abstract Magnetite (Fe 3 O 4) is a well-recognized petrogenetic indicator and is a common
accessory mineral in many ore deposits and their host rocks. Recent years have seen an …

This textbook is a complete rewrite, and expansion of Hugh Rollinson's highly successful
1993 book Using Geochemical Data: Evaluation, Presentation, Interpretation. Rollinson and …

Global data for measured Fe 2 O 3/FeO ratios and Cu contents in unaltered volcanic and
intrusive arc rocks indicate that, on average, they are slightly more oxidized than other …

Chondrite normalized rare earth element (REE) patterns of zircons generally have enriched
Ce values relative to La and Pr, and depleted Eu values relative to Sm and Gd. High Ce …

Redox-sensitive transition group elements are involved in almost all fundamental
geochemical processes. Of these elements, vanadium (V) contributes a particularly powerful …

Arc magmas are important building blocks of the continental crust. Because many arc lavas
are oxidized, continent formation is thought to be associated with oxidizing conditions. On …

Exchange between a magma ocean and vapor produced Earth's earliest atmosphere. Its
speciation depends on the oxygen fugacity (f O2) set by the Fe3+/Fe2+ ratio of the magma …

Magmatic outgassing of volatiles from Earth's interior probably played a critical part in
determining the composition of the earliest atmosphere, more than 4,000 million years (Myr) …

The abundances of 60 elements in 616 Ocean Floor Basaltic (OFB) glasses from the
Abyssal Volcanic Glass Data File (AVGDF) of the Smithsonian Institution have been …