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Spatio-Temporal Variation of Polymetallic Mineralization in the Wooseok Deposit
우석광상 다금속 광화작용의 시공간적 특성변화
Econ. Environ. Geol. 2018 Dec;51(6):493-507
Published online December 31, 2018;  https://doi.org/10.9719/EEG.2018.51.6.493
Copyright © 2018 the Korean society of economic and environmental gelology.

Heonkyung Im, Dongbok Shin*, Junyeong Jeong, Moontaek Lee
임헌경 ·신동복* ·정준영 ·이문택

Department of Geoenvironmental Sciences, Kongju National University
공주대학교 지질환경과학과
Received November 5, 2018; Accepted December 15, 2018.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
 Abstract
The Wooseok deposit in Jecheon belongs to the Hwanggangri Mineralized Distict of the northeastern Ogcheon Metamorphic Belt. Its geology consists mostly of limestone of the Choseon Supergroup and the Cretaceous Muamsa granite intruded at the eastern area of the deposit. The deposit shows vertical occurrence of skarn and hydrothermal vein ores with W-Mo-Fe and Cu-Pb-Zn mineralization and skarn is developed only at lower levels of the deposit. Skarn minerals are replaced or cut by ore minerals in paragenetic sequence of magnetite-hematite, molybdenite-scheelite-wollframite, and higher abundances of pyrrhotite-chalcopyrite-pyrite-sphalerite-galena. Garnet has chemical compositions of Ad65.9-97.8Gr0.3-32.0Pyr0.9-3.0, corresponding to andradite series, and pyroxene compositions are Hd4.5-49.7Di42.3-93.9Jo0.5-7.9, prevailing in diopside compositions, both of which suggest oxidized conditions of skarnization. On the FeS-MnS-CdS ternary diagram, FeS contents of sphalerite in vein ores decrease with increasing MnS contents from bottom to top levels, possibly relating to W mineralization in deep and Pb-Zn mineralization in shallow level. Sulfur isotope values of sulfide minerals range from 5.1 to 6.8‰, reflecting magmatic sulfur affected by host rocks. W-Mo skarn and Pb-Zn vein mineralization in the Wooseok deposit were established by spatio-temporal variation of decreasing temperature and oxygen fugacity with increasing sulfur fugacity from bottom to top levels.
Keywords : Wooseok deposit, polymetallic mineralization, skarn, sphalerite, sulfur isotope

 

December 2018, 51 (6)