Zircon U-Pb age, trace element and Hf isotope composition of Sepon Au-Cu deposit, Laos: tectonic and metallogenic implications

Xin-yu Wang; Dian-hua Cao; Zong-qi Wang; An-jian Wang; Yu-dong Wu

doi:10.31035/cg2018006

2018 Vol. 1, No. 1

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Article navigation > China Geology > 2018 > 1(1): 36-48

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Xin-yu Wang, Dian-hua Cao, Zong-qi Wang, An-jian Wang, Yu-dong Wu, 2018. Zircon U-Pb age, trace element and Hf isotope composition of Sepon Au-Cu deposit, Laos: tectonic and metallogenic implications, China Geology, 1, 36-48. doi: 10.31035/cg2018006

Citation:

Zircon U-Pb age, trace element and Hf isotope composition of Sepon Au-Cu deposit, Laos: tectonic and metallogenic implications

a.
School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
b.
MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China

More Information

Corresponding author: Cao Dianhua email address: dianhuacao@gmail.com

Received Date: 28 November 2017

Revised Date: 28 January 2018

Accepted Date: 02 February 2018

Available Online: 27 February 2018

Publish Date: 25 March 2018

Abstract

Abstract

The Truong Son Fold Belt, located at the northeastern margin of the Indochina Block, is considered to be tectonically linked to the subduction of the Paleotethys Ocean and subsequent collision. Sepon is one of the most important super large deposits of the Truong Son Fold Belt. Our LA-ICP-MS zircon U-Pb dating results show that granodiorite porphyry samples from the Sepon deposit have ages of 302.1±2.9 Ma, which is a crucial phase for magmatic-tectonical activities from the Late Carboniferous to Early Permian and has avital influence on the mineralization of copper and gold. Zircon from granodiorite porphyry yields ε_Hf (t) values of 4.32 to 9.64, and T_DM2 has an average age of 914 Ma, suggesting that the source of the granodiorite porphyry in the region were mainly mantle components but underwent mixing and contamination of crust materials. The Ce⁴⁺/Ce³⁺ value of zircon in the granodiorite porphyry varys greatly from 2.4 to 1438.29, which shows magma mixing might occur. Considering the characteristics of trace elements in the zircon and the whole rock geochemical characteristics of intrusion rocks as well as the characteristics of regional volcanic-sedimentary association, it is indicated that the tectonic setting may be the continental arc environment. The Sepon Au-Cu deposit is derived from emplacement of calc-alkaline intermediate-acid magma with coming from deep sources in the subduction process of the Paleotethys Ocean, forming porphyry Mo-Cu, skarn Cu-Au mineralization and a hydrothermal sedimentary-hosted Au mineralization in the wall rocks.
- granodiorite porphyry /
- Zircon U-Pb ages /
- Hf isotope /
- Trace elements /
- Sepon /
- Laos

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References

[1]	Amelin Y, Lee DC, Halliday AN. 2000. Early-Middle Archaeancrustal evolution deduced from Lu-Hf and U-Pb isotopic studies ofsingle zircon grains. Geochimica et Cosmochimica Acta, 64(24), 4205-4225. Google Scholar
[2]	Andersen T. 2002. Correction of common lead in U-Pb analyses that don’t report ²⁰⁴Pb. Chem. Geol., 192(1-2), 59-79. Google Scholar
[3]	Backhouse D. 2004. Geological Setting, Alteration and Nature of Mineralization at the Phu KhamCopper-Gold Deposit. Laos PDR. CODES.University of Tasmania, Hobart, 75. Google Scholar
[4]	Ballard JR, Palin MJ, Campbell IH. 2002. Relative oxidation states of magmas inferred from Ce(IV)/Ce(III) in zircon: application to porphyry copper deposits of northern Chile. Contributions to Mineralogy & Petrology, 144(3), 347-364. Google Scholar
[5]	Bea F, Pereira, MD, Stroh, A. 1994. Mineral/leucosome trace-element partitioning in a peraluminous migmatite (a laser ablation-ICP-MS study). Chemical Geology, 117, 291-312. Google Scholar
[6]	Breiter K, Müller A, Shail R, et al. 2016. Composition of zircons from the Cornubian Batholith of SW England and comparison with zircons from other European Variscan rare-metal granites. Mineralogical Magazine, 80(7), 1273-1289. Google Scholar
[7]	Cannell J, Smith S. 2008. High-grade supergene enriched and exotic copper deposits in the Sepon Mineral District, Lao PDR. Proceedings of PACRIM Congress 2008, Gold Coast, Queensland, 355-361. Google Scholar
[8]	Cromie PW. 2010.Geological setting, geochemistry and genesis of the Sepon gold and copper deposits, Laos. PhD thesis, University of Tasmania. Google Scholar
[9]	Cromie PW, Khin Z, Smith S. 2006. New insights through LA- ICPMS and sulphur isotope investigations into the occurrence of gold in the Sepon gold deposits, Laos//18th Australian Earth Sciences Convention (AESC), Melbourne. Google Scholar
[10]	Elhlou S, Belousova E, Griffin WL, Pearson NJ, O’Reilly SY. 2006. Trace element and isotopic composition of GJ-red zirconstandard by laser ablation. Geochimica et Cosmochimica Acta, 70(18), A158. Google Scholar
[11]	Fontaine H, Workman DR. 1978. Review of the geology and mineral resources of Kampuchea, Laos and Vietnam: Third regional conference on geology and mineral resources of southeast Asia, Bangkok, Thailand, 541-603. Google Scholar
[12]	Grimes CB, John B E, Kelemen PB, Mazdab FK, Wooden JL, Cheadle MJ, Hanghøj K, Schwartz JJ. 2007. Trace element chemistry of zircons from oceanic crust: A method for distinguishing detrital zircon provenance. Geology, 35(7), 643-646. Google Scholar
[13]	Hoskin PW, Ireland TR. 2000. Rare earth element chemistry of zircon and its use as a provenance indicator. Geology, 28, 627-630. Google Scholar
[14]	Hotson MD. 2009. The geochronology and tectonic framework of Cu-Au Prospects in the Phonsovan district, northern Laos. Unpublished BSc (Hons) thesis, ARC Centre of Excellence in Ore Deposits (CODES), University of Tasmania, Hobart, Australia, 158. Google Scholar
[15]	Hou KJ, Li YH, Zou TR, Qu XM, Shi YR, Xie GQ. 2007. Laserablation-MC-ICP-MS technique for Hf isotope microanalysis of zirconand its geological applications. Acta Petrologica Sinica, 23(10), 2595-2604. Google Scholar
[16]	Peytcheva I, Quadt VA, Neubauer F, et al. 2009. U-Pb dating, Hf-isotope characteristics and trace-REE-patterns of zircons from Medet porphyry copper deposit, Bulgaria: implications for timing, duration and sources of ore-bearing magmatism. Mineralogy and Petrology, 96(1-2), 19. Google Scholar
[17]	Jia RX, Fang WX, Wei XY. 2014. General introduction of geology, mineral resources and mining exploitation in Laos. 5(5):826-833. (in Chinese with English abstract) Google Scholar
[18]	Kamvong T. 2013. Geology and Genesis of Porphyry-skarn Cu-Au Deposits of the Northern Loei and Truong Son Fold Belts. Unpublished PhD thesis, ARC Centre of Excellence in Ore Deposits (CODES), University of Tasmania, Hobart, Australia, 169. Google Scholar
[19]	Kamvong T, Zaw K, Meffre S, et al. 2014. Adakites in the Truong Son and Loei fold belts, Thailand and Laos: Genesis and implications for geodynamics and metallogeny. Gondwana Research, 26(1), 165-184. Google Scholar
[20]	Khin Z, Sebastien M, Chun KL, Clive BM, Santosh IanG, Takayuki M, Abhisit S, Teera K, Paul C. 2014. Tectonics and metallogeny of mainland Southeast Asia-A review and contribution. Gondwana Research, 26(1), 5-30. Google Scholar
[21]	Lai CK, Meffre S, Crawford AJ, et al. 2014. The Western Ailaoshan Volcanic Belts and their SE Asia connection: A new tectonic model for the Eastern Indochina Block. Gondwana Research, 26(1), 52-74. Google Scholar
[22]	Lepvrier, C, Maluski, H, Vuong, N.V, Roques, D, Axente, V, Rangin, C. 1997. Indosinian NW-trending shear zones within the Truong Son belt (Vietnam):⁴⁰Ar-³⁹Ar Triassic ages and Cretaceous to Cenozoic overprints. Tectonophysics, 283, 105-127. Google Scholar
[23]	Li YF. 2012. Granites Geochemical Characteristics and Era Research of the Skarntype Iron Ore Deposit in Pha Lek Fe mine area, Laos. Unpublished Master’s Thesis, China University of Geosciences (Beijing), Beijing, China, 10-33 (in Chinese with English abstract). Google Scholar
[24]	Liu JH, Liu FL, Ding ZJ, Liu PH, Wang F. 2014. U-Pb dating and Hf isotope study of Early Archean zircons from the Jiaobei Terrane, North China Craton: Evidence for growth and recycling of ancient continental crust. Acta Petrologica Sinica, 30(10), 2941-2950. Google Scholar
[25]	Liu JL, Tran MD, Tang Y, Nguyen QL, Tran TH, Wu WB, Chen JF, Zhang ZC, Zhao ZD. 2012. Permo-Triassic granitoids in the northern part of the TruongSon belt, NW Vietnam: geochronology, geochemistry and tectonic implications. Gondwana Research, 22, 628-644. Google Scholar
[26]	Lu YJ, Loucks RR, Fiorentini M, et al. 2016. Zircon compositions as a pathfinder for porphyry Cu ± Mo ± Au deposits//Society of Economic Geologists Special Publication No. 19 on Tethyan Tectonics and Metallogeny. Google Scholar
[27]	Maluski H, Lepvrier C, Leyreloup A, VanTich V, Thi PT. 2005. ⁴⁰Ar-³⁹Ar geochronology of the charnockites and granulites of the Kan Nack complex, Kontum Massif, Vietnam: Journal of Asian Earth Sciences, 25, 653-677. Google Scholar
[28]	Manaka T, Zaw K, Meffre S, et al. 2014. The Ban Houayxai epithermal Au-Ag deposit in the Northern Lao PDR: Mineralization related to the Early Permian arc magmatism of the Truong Son Fold Belt. Gondwana Research, 26(1), 185-197. Google Scholar
[29]	Manaka T, Zaw K, Meffre S. 2008. Geological and Tectonic Settingof Cu-Au Deposits in Northern Lao PDR. Proceedings of the InternationalSymposia on Geoscience Resources and Environmentsof Asian Terranes (GREAT 2008) ,4th IGCP 516, and 5th APSEG; November 24 -26, Bangkok,Thailand. Google Scholar
[30]	Manini AJ, Albert P. 2003. Exploration and development of the Sepon gold and copper projects, Laos, Australian Institute of Geoscience-Asian Update Symposium, Sydney Mineral Exploration Discussion Group. Google Scholar
[31]	Nardi LVS, Formoso MLL, Müller IF, Fontana E, Jarvis K, Lamarão C. 2013. Zircon/rock partition coefficients of REEs, Y, Th, U, Nb, and Ta in granitic rocks: Uses for provenance and mineral exploration purposes. Chemical Geology, 335, 1-7. Google Scholar
[32]	Sano Y, Terada K, Fukuoka T. 2002. High mass resolution ion microprobe analysis of rare earth elements in silicate glass, apatite and zircon: lack of matrix dependency. Chemical Geology, 184, 217-230. Google Scholar
[33]	Schulz B, Klemd R, Brätz H. 2006. Host rock compositional controls on zircon trace element signatures in metabasites from the Austroalpine basement. Geochimica Et Cosmochimica Acta, 70(3), 697-710. Google Scholar
[34]	Shi MF, Lin FC, Fan WY. 2015. Zircon U -Pb ages and geochemistry of granitoids in the Truong Son terrane, Vietnam: Tectonic and metallogenic implications. Journal of Asian Earth Sciences, 101, 101-120. Google Scholar
[35]	Shi MF, Lin FC, Zhu HP, Wang H, Deng Q. 2017. Geological and mineral resources characteristics and exploration potential along the China-Singapore economic corridor. Geological Bulletin of China, 36(1), 16-34. Google Scholar
[36]	Siebel W, Blaha U, Chen F, Rohrmüller J. 2005. Geochronology and geochemistry of a dyke-host rock association and implications for the formation of the Bavarian Pfahl shear zone, Bohemian Massif. International Journal of Earth Sciences, 94(1), 8-23. Google Scholar
[37]	Söderlund U, Patchett PJ, Vervoort JD, Isachsen CE. 2004. The ¹⁷⁶Lu decay constant determined by Lu-Hf and U-Pb isotope systematics of Precambrian mafic intrusions. Earth & Planetary Science Letters, 219(3-4), 311-324. Google Scholar
[38]	Stokes, RB, Smith, GF.1990. A review of the geology, structure and sedimentary basins of Laos: Gloucestershire, Integrated Exploration and Development Services Ltd, 1-161. Google Scholar
[39]	Sun SS, Mcdonough WF. 1989. Chemical and Isotopic Systematics of Oceanic Basalts; Implications for Mantle Composition and Processes. Geological Society London Special Publications, 42(1), 313-345. Google Scholar
[40]	Tate NM. 2005. Discovery, geology and mineralisation of the Phu Kham copper-gold deposit Lao People’s Democratic Republic//Mineral Deposit Research: Meeting the Global Challenge. Springer Berlin Heidelberg. Google Scholar
[41]	Thomas JB, Bodnar RJ, Shimizu N, Sinha AK. 2002. Determination of zircon/melt trace element partition coefficient from SIMS analysis of melt inclusions in zircon. Geochim Cosmochim Acta, 66, 2887-2901. Google Scholar
[42]	Vervoort JD, Pachelt PJ, Gehrels GE, Nutman AP. 1996. Constraintson early earth differentiation from hafnium and neodymium isotopes. Nature, 379(6566), 624-627. Google Scholar
[43]	Wang XD, Lin W, Shen, SZ, Chaodumrong P, Shi GR, Wang XJ, Wang QL. 2013. Early Permian rugose coral Cyathaxonia faunas from the Sibumasu Terrane (Southeast Asia) and the southern Sydney Basin (Southeast Australia): palaeontology and palaeobiogeography. Gondwana Research. 24, 185-191. Google Scholar
[44]	Workman, D. R..1975.Tectonic evolution of Indochina: Journal of the Geological Society of Thailand, 1, 3-19. Google Scholar
[45]	Wu FY, Li XH, Zheng YF, Gao S. 2007. Lu-Hf isotopic systematics and their applications in petrology. Acta Petrologica Sinica, 23(2), 185-220 (in Chinese with English abstract). Google Scholar
[46]	Wu YB, Zheng YF. 2004. Genesis of zircon and its constraints on interpretation of U-Pb age. Chinese Science Bulletin, 49(15), 1554-1569. Google Scholar
[47]	Zaw KM, Sebastien L, Kit S, Burrett M, Clive G, Ian M, Takayuki S, Abhisit K, Teera CP. 2014.Tectonics and metallogeny of mainland Southeast Asia-A review and contribution. Gondwana Research, 26. Google Scholar
[48]	Zhu HP, Fan WY, Wang H, Lin FC. 2013. New Research Progress on Sepon Copper and Gold Deposits, Laos, Geological Science and Technology Information, 32(5),182-187 (in Chinese with English abstract). Google Scholar