Variable redox states of sulfur in porphyry copper-fertile arc magmas.

Authors

Xuyang Meng, Adam C Simon, Jingwen Mao, Brian A Konecke, Kouki Kitajima, Owen K Neill

Published in

Science advances. Volume 12. Issue 36. Pages eaed1386. Sep 04, 2026. Epub Sep 04, 2026.

Abstract

Porphyry copper systems formed in magmatic arcs represent the largest concentrations of copper and most massive anomalies of sulfur worldwide. Whether the ore-fluid-source magmas were dominated by oxidized or reduced sulfur remains the subject of intense debate. Here, we quantitatively measured in situ the relative abundances of S⁶⁺, S⁴⁺, and S^2- in sulfur-bearing primary apatite grains hosted in zircon, amphibole, and biotite in igneous rocks related to porphyry and skarn copper-gold deposits in the Middle-Lower Yangtze River metallogenic belt, Eastern China. Calculated S⁶⁺/ΣS ratios of the sulfur-bearing apatite grains vary from 0.18 to 0.97 and are independent of the crystallization pressure and temperature of their host minerals. The data reveal two distinct groups of ore-fluid-source magmas: (i) highly oxidized, dominantly sulfate (anhydrite)-saturated and (ii) relatively reduced, dominantly sulfide-saturated. The results demonstrate that economic porphyry copper systems can form from intermediate-felsic magmas over a broad range of S⁶⁺/ΣS ratios and oxygen fugacities (fO₂), possibly throughout Earth history including the Proterozoic and Archean.

PMID:
42696598
Bibliographic data and abstract were imported from PubMed on 05 Sep 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.