Martin J. Streck, John H. Dilles; Sulfur evolution of oxidized arc magmas as recorded in apatite from a porphyry copper batholith. Geology 1998; 26 (6): 523-526. doi: 10.1130/0091-7613(1998)026<0523:SEOOAM>2.3.CO;2
Download citation file:
Uniformly sulfur-rich cores abruptly zoned to sulfur-poor rims (∼1 to <0.2 wt% SO3) in apatite from the Yerington batholith, Nevada, indicate that early magma that is crystal poor, oxidizing, and sulfate rich evolved to sulfate-poor magma via crystallization of anhydrite, a mineral observed in magmas from Pinatubo and El Chichón. We predict that the characteristic zonation to sulfur-poor rims of apatite in the Yerington batholith is common in other oxidized, hydrous, calc-alkaline magmas, and can be used to track cryptic anhydrite saturation as well as to monitor sulfur evolution. Sulfate-rich arc magmas such as Yerington magmas may crystallize to produce hydrothermal fluids rich in chlorine, copper, and sulfur and porphyry copper ores.