EPMA Analysis of Hydrothermal Biotite from the Bangpu Porphyry Mo-Cu Deposit of Tibet, China and the Characteristics of Early Ore-forming Fluids

Yong WANG; Ju-xing TANG; Li-qiang WANG

doi:10.15898/j.cnki.11-2131/td.2016.04.017

2016 Vol. 35, No. 4

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Article navigation > Rock and Mineral Analysis > 2016 > 35(4): 440-447

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Yong WANG, Ju-xing TANG, Li-qiang WANG. EPMA Analysis of Hydrothermal Biotite from the Bangpu Porphyry Mo-Cu Deposit of Tibet, China and the Characteristics of Early Ore-forming Fluids[J]. Rock and Mineral Analysis, 2016, 35(4): 440-447. doi: 10.15898/j.cnki.11-2131/td.2016.04.017

Citation:

Yong WANG, Ju-xing TANG, Li-qiang WANG. EPMA Analysis of Hydrothermal Biotite from the Bangpu Porphyry Mo-Cu Deposit of Tibet, China and the Characteristics of Early Ore-forming Fluids[J]. Rock and Mineral Analysis, 2016, 35(4): 440-447. doi: 10.15898/j.cnki.11-2131/td.2016.04.017

EPMA Analysis of Hydrothermal Biotite from the Bangpu Porphyry Mo-Cu Deposit of Tibet, China and the Characteristics of Early Ore-forming Fluids

1.
School of Earth Sciences and Resources, China University of Geosciences(Beijing), Beijing 100083, China
2.
Key Laboratory of Metallogeny and Mineral Assessment, Ministry of Land and Resources, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China

More Information

Corresponding author: Li-qiang WANG, wlq060301@163.com

Received Date: 24 November 2015

Revised Date: 13 April 2016

Accepted Date: 12 July 2016

Abstract

Abstract

The chemical composition of hydrothermal biotite is important in revealing the physiochemical conditions and evolution of early ore-forming fluids. The Bangpu deposit is a large porphyry Mo(Cu) deposit in the eastern part of the Gangdese metallogenic belt, and hydrothermal biotite is extensive in the potassic alteration zone. Hydrothermal biotite in the potassic alteration zone of dioritic porphyry was analyzed by Electron Microprobe Analyzer (EPMA) and is reported in this paper. Results show that the biotite is characterized by the high content of K and low contents of Na and Ca. The average contents of SiO₂, TiO₂, Al₂O₃, FeO^T, MgO, K₂O are 38.95%, 1.42%, 13.55%, 14.22%, 16.23%, 9.77%, respectively. The anomalously high K/Na values (82.5) may be an important indicator for the porphyry Mo mineralization. Based on chemical components, the temperature and oxygen fugacity of the ore-forming fluids were calculated. Results show that the early ore-forming fluids of the potassic alteration have a high temperature and oxygen fugacity, and the average temperature (458℃) of the deep ore-forming fluids is much higher than that of the shallow ore-forming fluids (366℃) . The decreasing temperature and pressure during the migration of the early ore-forming fluids from deep to shallow resulted in the precipitation of the Mo and Cu sulfides. This research provides an important clue for studying the evolution of ore-forming fluids and the ore-forming mechanism.
- hydrothermal biotite /
- Electron Microprobe /
- physico-chemical condition /
- porphyry deposit /
- Bangpu

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References

[1]	Ayati F,Yavuz F,Noghreyan M,et al.Chemical Characteristics and Composition of Hydrothermal Biotite from the Dalli Porphyry Copper Prospect,Arak,Central Province of Iran[J].Mineralogy Petrology,2008,94(1):107-122. Google Scholar
[2]	Bath A B,Walshe J L,Cloutier J,et al.Biotite and Apatite as Tools for Tracking Pathways of Oxidized Fluids in the Archean East Repulse Gold Deposit,Australia[J].Economic Geology,2013,108(4):667-690. doi: 10.2113/econgeo.108.4.667 CrossRef Google Scholar
[3]	Afshooni S Z,Mirnejad H,Esmaeily D,et al.Mineral Chemistry of Hydrothermal Biotite from the Kahang Porphyry Copper Deposit (NE Isfahan),Central Province of Iran[J].Ore Geology Reviews,2013,54(32):214-232. Google Scholar
[4]	Parsapoor A,Khalili M,Tepley F,et al.Mineral Chemistry and Isotopic Composition of Magmatic,Re-equilibrated and Hydrothermal Biotites from Darreh-Zar Porphyry Copper Deposit,Kerman (Southeast of Iran)[J].Ore Geology Reviews,2015,66:200-218. doi: 10.1016/j.oregeorev.2014.10.015 CrossRef Google Scholar
[5]	Beane R E.Biotite Stability in the Porphyry Copper Environment[J].Economic Geology,1974,69(2):241-256. doi: 10.2113/gsecongeo.69.2.241 CrossRef Google Scholar
[6]	Wones D R,Eugster H P.Stability of Biotite:Experiment,Theory and Application[J].American Mineralogist,1965,50(9):1228-1272. Google Scholar
[7]	赵晓燕,杨竹森,刘英超,等.西藏邦铺斑岩矽卡岩矿床二长花岗斑岩Sr-Nd-Pb-Hf同位素及闪锌矿黄铁矿Rb-Sr等时线年龄研究[J].地质学报,2015,89(3):522-533. Google Scholar Zhao X Y,Yang Z S,Liu Y C,et al.Sr-Nd-Pb-Hf Isotope of Porphyritic Monzogranite and Rb-Sr Isochron Age of Sphalerite-Pyrite at the Bangpu Porphyry-Skarn Deposit[J].Acta Geology Sinica,2015,89(3):522-533. Google Scholar
[8]	王立强,唐菊兴,王登红,等.西藏墨竹工卡县邦铺钼(铜)矿床辉钼矿稀土-微量元素特征及对成矿流体性质的指示[J].地质论评,2012,58(5):887-892. Google Scholar Wang L Q,Tang J X,Wang D H,et al.Rare Earth Element and Trace Element Features of Molybdenite in Bangpu Mo(Cu) Deposite,Maizhokunggar,Xizang (Tibet),and Their Constraints on the Nature of Ore-forming Fluid[J].Geological Review,2012,58(5):887-892. Google Scholar
[9]	Wang L Q,Tang J X,Cheng W B,et al.Origin of the Ore-forming Fluids and Metals of the Bangpu Porphyry Mo-Cu Deposit of Tibet,China:Constraints from He-Ar,H-O,S and Pb Isotopes[J].Journal of Asian Earth Sciences,2015,103(1):276-287. Google Scholar
[10]	周雄,温春齐,霍艳,等.西藏墨竹工卡地区邦铺钼铜多金属矿床成矿流体的特征[J].地质通报,2010,29(7):1039-1048. Google Scholar Zhou X,Wen C Q,Huo Y,et al.Characteristics of Ore-forming Fluid of Bangpu Molybdenum-Copper Polymetallic Deposit, Maizhokunggar Area,Tibet,China[J].Geological Bulletin of China,2010,29(7):1039-1048. Google Scholar
[11]	罗茂澄,毛景文,王立强,等.西藏邦铺斑岩钼铜矿床岩浆——热液流体演化:流体包裹体研究[J].地球学报,2012,33(4):471-484. Google Scholar Luo M C,Mao J W,Wang L Q,et al.Fluid Inclusion Evidence for Magmatic-Hydrothermal Evolution in the Bangpu Porphyry Molybdenum-Copper Deposit,Tibet[J].Acta Geoscientica Sinica,2012,33(4):471-484. Google Scholar
[12]	赵晓燕,杨竹森,周金胜,等.西藏邦铺斑岩矽卡岩矿床成矿流体特征——来自流体包裹体及C-H-O同位素的制约[J].岩石矿物学杂志,2015,34(4):475-492. Google Scholar Zhao X Y,Yang Z S,Zhou J S,et al.Characteristics of Ore-forming Fluids in the Bangpu Porphyry-Skarn Deposit:Evidence from Fluid Inclusions and Stable Isotope Compositions[J].Acta Petrologica et Mineralogica,2015,34(4):475-492. Google Scholar
[13]	Yavuz F.Evaluating Micas in Petrologic and Metallo-genic Aspect:Ⅰ-Definitions and Structure of the Computer Program Mica⁺[J].Computer & Geoscience,2003,29(10):1203-1213. Google Scholar
[14]	秦克章,张连昌,丁奎首,等.东天山三岔口铜矿床类型、赋矿岩石成因与矿床矿物学特征[J].岩石学报,2009,25(4):845-861. Google Scholar Qin K Z,Zhang L C,Ding K S,et al.Mineralization Type,Petrogenesis of Ore-bearing Intrusions and Mineralogical Characteristics of Sanchakou Copper Deposits in Eastern Tishan[J].Acta Petrologica Sinica,2009,25(4):845-861. Google Scholar
[15]	Foster M D.Interpretation of the Composition of Triocta-hedral Micas[R].Virginia:United States Geological Survey,1960,354-B:1-146. Google Scholar
[16]	Stone D.Temperature and Pressure Variations in Suites of Archean Felsic Plutonic Rocks,Berens River Area,Northwest Superior Province,Ontario,Canada[J].The Canadian Mineralogist,2000,38:455-470. doi: 10.2113/gscanmin.38.2.455 CrossRef Google Scholar
[17]	于玉帅,杨竹森,高原,等.西藏尼雄矿田滚纠铁矿花岗闪长岩成因的矿物化学证据[J].地质与勘探,2013, 49(5):897-906. Google Scholar Yu Y S,Yang Z S,Gao Y,et al.Genesis of Granodiorite in the Gunjiu Iron Deposit of the Nixiong Ore Field,Tibet: Evidence from Mineral Chemistry[J].Geology and Exploration,2013,49(5):897-906. Google Scholar
[18]	Jacobs D C,Parry W T.Geochemistry of Biotite in the Santa Rita Porphyry Copper Deposit,New Mexico[J].Economic Geology,1979,74(4):860-887. doi: 10.2113/gsecongeo.74.4.860 CrossRef Google Scholar
[19]	Siahcheshm K,Calagari A A,Abedini A,et al.Halogen Signatures of Biotites from the Maher-Abad Porphyry Copper Deposit,Iran:Characterization of Volatiles in Syn- to Post-Magmatic Hydrothermal Fluids[J].International Geology Review,2012,54(12):1353-1368. doi: 10.1080/00206814.2011.639487 CrossRef Google Scholar
[20]	谢富伟,唐菊兴,郎兴海.西藏雄村矿区Ⅰ号矿体斑岩含矿性研究——来自热液蚀变矿物和副矿物的证据[J].岩石矿物学杂志,2015,34(1):51-64. Google Scholar Xie F W,Tang J X,Lang X H.Ore Potential of the Porphyry in No.Ⅰ Deposit of the Xiongcun Ore District,Tibet:Evidence from Hydrothermal and Accessory Minerals[J].Acta Petrologica et Mineralogica,2015,34(1):51-64. Google Scholar
[21]	Boomeri M,Nakashima K,Lentz D R.The Sarcheshmeh Porphyry Copper Deposit,Kerman,Iran:A Mineralogical Analysis of the Igneous Rocks and Alteration Zones including Halogen Element Systematics Related to Cu Mineralization Processes[J].Ore Geology Reviews,2010,38(4):367-381. doi: 10.1016/j.oregeorev.2010.09.001 CrossRef Google Scholar
[22]	Wones D R.Significance of the Assemblage Titanite+Magnetite+Quartz in Granitic Rocks[J].American Mineralogist,1989,74(7):744-749. Google Scholar
[23]	Albuquerque A C.Geochemistry of Biotites from Granitic Rocks,Northern Portugal[J].Geochimica et Cosmochimica Acta,1973,37(7):1779-1802. doi: 10.1016/0016-7037(73)90163-4 CrossRef Google Scholar
[24]	Rusk B G,Reed M H,Dilles J H.Fluid Inclusion Evidence for Magmatic-Hydrothermal Fluid Evolution in the Porphyry Copper-Molybdenum Deposit at Butte,Montana[J].Economic Geology,2008,103(2):307-334. doi: 10.2113/gsecongeo.103.2.307 CrossRef Google Scholar
[25]	Sillitoe R H.Porphyry Copper Systems[J].Economic Geology,2010,105(1):3-41. doi: 10.2113/gsecongeo.105.1.3 CrossRef Google Scholar
[26]	刘彬,马昌前,刘园园,等.鄂东南铜山口铜(钼)矿床黑云母矿物化学特征及其对岩石成因与成矿的指示[J].岩石矿物学杂志,2010,29(2):151-165. Google Scholar Liu B,Ma C Q,Liu Y Y,et al.Mineral Chemistry of Biotites from the Tongshankou Cu-Mo Deposit:Implications for Petrogenesis and Mineralization[J].Acta Petrologica et Mineralogica,2010,29(2):151-165. Google Scholar
[27]	弥佳茹,袁顺达,原垭斌,等.湘南宝山矿床花岗闪长斑岩中黑云母的矿物学特征及其指示意义[J].矿床地质,2014,33(6):1357-1365. Google Scholar Mi J R,Yuan S D,Yuan Y B,et al.Mineral Chemistry of Biotites in Baoshan Granodiorite-Porphyry,Southern Hunan Province:Implications for Petrogenesis and Mineralization[J].Mineral Deposits,2014,33(6):1357-1365. Google Scholar