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Titolo:
MINERALOGIC AND STABLE-ISOTOPE STUDIES OF CASSITERITE GREISEN MINERALIZATION IN THE ULJIN AREA, KOREA
Autore:
MOON SH; PARK HI; RIPLEY EM; LEE I;
Indirizzi:
KOREA INST GEOL MIN & MAT,YUSONG KU,GAJUNG DONG 30 TAEJON 305333 SOUTH KOREA SEOUL NATL UNIV,DEPT GEOL SCI SEOUL 15742 SOUTH KOREA INDIANA UNIV,DEPT GEOL SCI BLOOMINGTON IN 47405 KOREA BASIC SCI INST,KUSUNG KU TAEJON 305333 SOUTH KOREA
Titolo Testata:
Economic geology and the bulletin of the Society of Economic Geologists
fascicolo: 5, volume: 91, anno: 1996,
pagine: 916 - 933
SICI:
0361-0128(1996)91:5<916:MASSOC>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
REPUBLIC-OF-KOREA; TUNGSTEN-MOLYBDENUM MINE; W-MO MINE; FLUID INCLUSION; HYDROTHERMAL SYSTEM; HYDROGEN ISOTOPE; SULFUR ISOTOPE; TRANSPORT; EVOLUTION; OXYGEN;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
68
Recensione:
Indirizzi per estratti:
Citazione:
S.H. Moon et al., "MINERALOGIC AND STABLE-ISOTOPE STUDIES OF CASSITERITE GREISEN MINERALIZATION IN THE ULJIN AREA, KOREA", Economic geology and the bulletin of the Society of Economic Geologists, 91(5), 1996, pp. 916-933

Abstract

Vein-type, greisen-related cassiterite deposits occur at the Uljin, Yuchang, and Dongseog mines in eastern Korea within a Precambrian pegmatite dike swarm, and locally, within granite gneiss and metasedimentary rocks. Paragenetic stages of mineralization and alteration are as follows: greisen I, albitization, K feldspathization, and greisen II. A late-stage of quartz-fluorite vug filling is present locally. K-Ar agedating of muscovite from the greisen I stage mineralization indicatesa crystallization age of 158 to 179 +/- 6 Ma, in close agreement withpreviously determined ages of 151 to 179 Ma (Chon et al., 1993). Two samples of muscovite from the pegmatites give ages of 696 +/- 15 and 778 +/- 14 Ma. Greisen-related tin mineralization occurred during the Middle Jurassic to Early Cretaceous and is much younger than either thepegmatite (Late Proterozoic) or the granite gneiss (Early Proterozoicbased on Rb/Sr studies of Hong, 1985, and Lee, 1988), Temperatures ofgreisen I stage mineralization, determined from fluid inclusion homogenization studies, arsenopyrite composition, and quartz-muscovite delta(18)O values, range from 450 degrees to 600 degrees C. The coexistence of sulfide and oxide minerals suggest that during ore deposition f(S2) increased and f(O2) was constant or decreased slightly. Fluid inclusion analyses indicate that the ore fluid was of low to moderate salinity (2.89-8.55 wt % NaCl equiv), with variable CO2 content. Oxygen andhydrogen isotope values of quartz and muscovite decrease along a distance of 1,500 m from the northeast (Uljin mine) to the southwest (Dongseog mine) and suggest that fluid delta(18)O and delta D values decreased from similar to 11 to 9 permil, and -55 to -61 per mil, respectively. A similar decrease in fluid delta(18)O and delta D values is recorded temporally with the paragenetic stage at the Uljin mine. Sulfur isotope values of arsenopyrite and molybdenite range from -1.2 to 1.2 per mil. A genetic model of fluid derivation from an underlying Mesozoicgranitic pluton, accompanied with the involvement of meteoric water in later stages, is proposed. Isotopic data are consistent with temporal and spatial variations in fluid delta D and delta(18)O values causedeither by tapping of a magmatic fluid during various stages of chemical and isotopic evolution, or by reaction and isotopic exchange,ae with high O-18 sedimentary rocks along a fluid Bow path. Variations in delta(18)O values of carbonate country rocks from 19.3 to 12.3 per mil are suggestive of selective fluid transport through particularly permeable units in the limestone. Low delta(18)O values of vug-filling quartz suggest the involvement of low-temperature meteoric water in the latest hydrothermal stages of mineralization.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/07/20 alle ore 21:41:13