Two-stage gold mineralization of the Axi epithermal Au deposit, Western Tianshan, NW China: Evidence from Re–Os dating, S isotope, and trace elements of pyrite
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F20%3A00524203" target="_blank" >RIV/67985831:_____/20:00524203 - isvavai.cz</a>
Result on the web
<a href="https://link.springer.com/article/10.1007/s00126-019-00903-6" target="_blank" >https://link.springer.com/article/10.1007/s00126-019-00903-6</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1007/s00126-019-00903-6" target="_blank" >10.1007/s00126-019-00903-6</a>
Alternative languages
Result language
angličtina
Original language name
Two-stage gold mineralization of the Axi epithermal Au deposit, Western Tianshan, NW China: Evidence from Re–Os dating, S isotope, and trace elements of pyrite
Original language description
The Axi gold deposit is one of the largest epithermal deposits in northwestern China and is characterized by multistage generations of pyrite associated with gold mineralization. Genetic models for superjacent epithermal Au and porphyry Cu systems involve either contemporaneous or episodic mineralization, implying different metal sources and ore-forming events. Nine pyrite separates from disseminated ores associated with pyrite-sericite-quartz alteration in the Axi deposit yield a Re–Os isochron age of 350 ± 10 Ma (MSWD = 5.1, initial 187Os/188Os (IOs) = 0.20 ± 0.11). This age likely reflects a mixed contribution of two subtypes of disseminated pyrite (Py1) based on zoned pyrite crystals. The isochron age of 353 ± 6 Ma (MSWD = 1.6, IOs = 0.107 ± 0.021, n = 6), excluding samples with pyrite cores, overlaps previous ages for andesite from the Dahalajunshan Formation (ca. 356 Ma), indicating that the early mineralization event occurred shortly after the formation of host rocks (ca. 353 Ma). Pyrite from disseminated ores shows little variation of sulfur isotopic compositions (+ 2.9 to + 4.0‰) and has high Cu, Co, Ni, and V contents, which favors a magmatic-hydrothermal origin. Pyrite grains from gray quartz veins yield a younger Re–Os isochron age of 332 ± 8 Ma (MSWD = 0.22, n = 4). Vein-hosted pyrite shows characteristics of a mantle-derived magma source (IOs: 0.171 ± 0.024, δ34S: − 0.10~+ 3.10‰), which result from the intrusion-driven convective hydrothermal circulation accompanying fluid exsolution and metal remobilization from basement and wallrocks. Our data demonstrate that the Axi gold deposit was formed during two temporally separated hydrothermal events. This model of ore formation may apply to other epithermal-porphyry deposits within the Axi–Tawuerbieke district: disseminated Au and porphyry-style Au ± Cu mineralization occurred shortly after magmatic activity (356–353 Ma) whereas epithermal-style Au mineralization occurred at ca. 332 Ma.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Mineralium deposita
ISSN
0026-4598
e-ISSN
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Volume of the periodical
55
Issue of the periodical within the volume
June
Country of publishing house
DE - GERMANY
Number of pages
18
Pages from-to
863-880
UT code for WoS article
000531831900002
EID of the result in the Scopus database
2-s2.0-85068235703