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The δ 18 O of UST Quartz in Two Porphyry Deposits, China
Author(s) -
Qu Huanchun,
Sun Maoyu,
Dong Pu
Publication year - 2017
Publication title -
resource geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 43
eISSN - 1751-3928
pISSN - 1344-1698
DOI - 10.1111/rge.12116
Subject(s) - quartz , geology , phenocryst , sericite , hydrothermal circulation , geochemistry , biotite , mineralogy , seismology , plagioclase , paleontology
The unidirectional solidification textures (UST) quartz is generally thought to form from fluids exsolved from shallow intrusions and/or magma chambers, but such an idea is still poorly constrained from the evidence of stable isotopes. In this study, we report for the first time the δ 18 O of quartz that shows UST from the Qulong Cu–Mo and the Yechangping Mo porphyry deposits in China. The analysis results show that the UST quartz samples from the Qulong deposit have δ 18 O values ranging from +6.2 ‰ to +7.6 ‰, which are similar to that of quartz phenocrysts (+6.7 ‰ to +7.8 ‰). In contrast, the UST quartz samples from the Yechangping porphyry Mo deposit yield a high δ 18 O value (+10.0 ‰). The δ 18 O water value of Yechangping UST quartz (+8.5 ‰) is also higher than that of Qulong (+4.6 ‰ to +5.8 ‰). Hydrothermal biotite from potassic alteration and sericite from early phyllic alteration at Qulong have similar δ 18 O values to UST quartz, suggesting the involvement of magmatic fluids during this stage of deposit evolution.