Zircon U-Pb Age and Geochemistry of Gabbro from Jiamate Au-Cu Ore District in Northern Junggar, China and Their Geological Significance

Abstract

Abstract:

Jiamate Cu-Au deposit is located in the northern margin of Junggar. The orebodies are hosted in the contact zone of gabbro and basalt of the Beitashan Formation, as well as within the quartz diorite and contact zone. Orebodies occur as vein and lenticular shape, and mineralization are related to quartz diorite and gabbro. The main wall rock alterations include epidotization, biotitization, chloritization, carbonatization, and magnetite mineralization. LA-ICP-MS zircon U-Pb dating of gabbro yields the age of 380 Ma, which constrains the age of Cu-Au mineralization later than 380 Ma. The gabbro samples show negative anomalies of Th, Nb, Ta, Ti, Nd and Zr, as well as positive anomalies of Rb, K, Pb and P. Combined with the enrichment of LREE and slightly negative to zero Eu anomalies, we propose the gabbro is related to subduction process and was formed in an island arc setting. The primitive magma originated from a mixture of mantle wedge that was modified by the subduction material and the asthenosphere. The magma was evolved and had experienced weak crustal contaminations.

Key words: gabbro, geochemistry, zircon U-Pb age, Jiamate ore district, Northern Junggar,Xinjiang

CLC Number:

P588.12

LI Yuanyou, LIU Guoren, YU Xiubin, LI Yan, QI Shijun, LI Qiang, JIN Jianbin. Zircon U-Pb Age and Geochemistry of Gabbro from Jiamate Au-Cu Ore District in Northern Junggar, China and Their Geological Significance[J]. Geoscience, 2017, 31(04): 651-661.

Figures/Tables 10

References 34

[1]	杜超辉, 赵华, 刘国仁, 等. 新疆青河县加玛特金铜矿床地质特征及找矿标志[J]. 新疆有色金属, 2015(2):44-45,48.
[2]	何国琦, 成守德, 徐新, 等. 中国新疆及邻区大地构造图(1∶2500000)说明书[M]. 北京: 地质出版社, 2004:1-65.
[3]	陈毓川, 刘德权, 王登红, 等. 新疆北准噶尔苦橄岩的发现及其地质意义[J]. 地质通报, 2004, 23(11):1059-1065.
[4]	ZHANG Z C, CAI J H, YAN S H, et al. A discussion on the low Ca olivine phenocrysts in Middle Devonian picritic lavas on the southern margin of the Altay Mountains[J]. Acta Petrologica et Mineralogica, 2008, 27(3):171-176.
[5]	吕书君, 杨富全, 柴凤梅, 等. 东准噶尔北缘老山口铁铜金矿区侵入岩LA-ICP-MS锆石U-Pb定年及地质意义[J]. 地质论评, 2012, 58(1):149-164.
[6]	NASDALA L, NORBERG N, SCHALTEGGER U. Plesovice zircon — A new natural reference material for U-Pb and Hf isotopic microanalysis[J]. Chemical Geology, 2008, 249: 1-35. DOI URL
[7]	侯可军, 李延河, 田有荣. LA-MC-ICP-MS锆石微区原位U-Pb定年技术[J]. 矿床地质, 2009, 28(4):481-492.
[8]	BELOUSOVA E A, GRIFFIN W L, OREILLY S Y, et al. Igneous zircon: trace element composition as an indicator of source rock type[J]. Contributions to Mineralogy and Petrology, 2002, 143: 602-622. DOI URL
[9]	WILSON M. Igneous Petrogenesis[M]. London: Kluwer Academic Publishers, 2001:1-100.
[10]	SUN S S, MCDONOUGH W F. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[J]. Geological Society, London,Special Publications, 1989, 42:313-345. DOI URL
[11]	柴凤梅, 杨富全, 刘锋, 等. 新疆准噶尔北缘北塔山组火山岩年龄及岩石成因[J]. 岩石学报, 2012, 28(7):2183-2198.
[12]	LI Qiang, LÜ Shujun, YANG Fuquan, et al. Geological characteristics and genesis of the Laoshankou Fe-Cu-Au deposit in Junggar, Xinjiang, Central Asian Orogenic belt[J]. Ore Geology Reviews, 2015, 68: 59-78. DOI URL
[13]	KULLERUD K, SKJERLIE K P, CORFU F, et al. The 2.4 Ga Ringvassoy mafic dykes, West Trom Basement complex, Norway: The concluding act of Early Palaeoproterozoic continental breakup[J]. Precambrian Research, 2006, 150(3/4):183-200. DOI URL
[14]	PEARCE J A. Geochemical fingerprinting of oceanic basalts with applications to ophiolite classfication and the search for Archean oceanic crust[J]. Lithos, 2008, 100(1/4):14-48. DOI URL
[15]	ZHANG C L, ZOU H B, YAO C Y, et al. Origin of Permian gabbroic intrusions in the southern margin of the Altai Orogenic belt: A possible link to the Permian Tarim mantle plume?[J]. Lithos, 2014, 204:112-124. DOI URL
[16]	李献华, 周汉文, 韦刚健, 等. 滇西新生代超钾质煌斑岩的元素和Sr-Nd同位素特征及其对岩石圈地幔组成的制约[J]. 地球化学, 2002, 31(1):26-34.
[17]	HOFMANN A W, JOCHUM K P, SEUFER METAL. Nb and Pb in oceanic basalts: New constraints on mantle evolution[J]. Earth and Planetary Science Letters, 1986, 79(1/2):33-45. DOI URL
[18]	SEGHEDI I, DOWNES H, VASELLI O. Post-collisional Tertiary-Quaternary mafic alkalic magmatism in the Carpathian-Pannonian region: a review[J]. Tectonophysics, 2004, 393:43-62. DOI URL
[19]	柴凤梅, 张招崇, 董连慧, 等. 新疆中天山白石泉含铜镍矿镁铁-超镁铁岩体地球化学特征与岩石成因[J]. 岩石学报, 2007, 23(10):2366-2378.
[20]	许继峰, 梅厚钧, 于学元, 等. 准噶尔北缘晚古生代岛弧中与俯冲作用有关的adakite火山岩:消减板片部分熔融的产物[J]. 科学通报, 2001, 46(8): 684-688.
[21]	张海祥, 牛贺才, HIROAKI Sato, 等. 新疆北部晚古生代埃达克岩、富铌玄武岩组合:古亚洲洋板块南向俯冲的证据[J]. 高校地质学报, 2004, 10(1):106-113.
[22]	李锦轶, 何国琦, 徐新, 等. 新疆北部及邻区地壳构造格架及其形成过程的初步探讨[J]. 地质学报, 2006, 80(1):148-165.
[23]	ZHANG Z C, YAN S H, CHEN B L, et al. SHRIMP zircon U-Pb dating for subduction-related granitic rocks in the northern part of east Junggar, Xinjiang[J]. Chinese Science Bulletin, 2006, 51(8): 952-962. DOI URL
[24]	周刚, 张招崇, 谷高中, 等. 新疆东准噶尔北部青格里河下游花岗岩类的时代及地质意义[J]. 现代地质, 2006, 20(1):141-150.
[25]	刘国仁, 秦纪华, 赵忠合, 等. 新疆阿尔泰额尔齐斯构造带片麻岩的锆石U-Pb SHRIMP 定年及其地质意义[J]. 现代地质, 2008, 22(2):190-196.
[26]	耿新霞, 左文喆, 陈风河, 等. 新疆准噶尔北缘索尔库都克铜钼矿氦-氩同位素组成及地质意义[J]. 现代地质, 2014, 28(2):331-338.
[27]	陈宏强, 马生明, 岑况, 等. 新疆东准噶尔拉伊克勒克斑岩型铜矿床岩石地球化学勘查及成矿预测[J]. 现代地质, 2016, 30(2):331-338.
[28]	ROGERS N W. Potassic magmatism as a key to trace element enrichment processes in the upper mantle[J]. Journal of Volcanolo-gy and Geothermal Research, 1992, 50:85-99.
[29]	CONDIE K C. Geochemistry and tectonic setting of Early Proterozoic supracrustal rocks in the southwestern United States[J]. The Journal of Geology, 1986, 94(6):845-864. DOI URL
[30]	MANIAR P D, PICCOLI P M. Tectonic discrimination of grani-toids[J]. Geological Society of America Bulletin, 1989, 101(5):635-643. DOI URL
[31]	PEARCE J A, HARRIS N B L, TINDLE A G. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks[J]. Journal of Petrology, 1984, 25: 956-983. DOI URL
[32]	吴淦国, 董连慧, 薛春纪, 等. 新疆北部主要斑岩铜矿带[M]. 北京: 地质出版社, 2008:1-345.
[33]	杨富全, 闫升好, 屈文俊, 等. 新疆哈腊苏铜矿床I号矿化带流体包裹体和碳氢氧同位素地球化学[J]. 地学前缘, 2010, 17(2):359-374.
[34]	YANG Fuquan, CHAI Fengmei, ZHANG Zhixin, et al. Zircon U-Pb geochronology, geochemistry, and Sr-Nd-Hf isotopes of granitoids in the Yulekenhalasu copper ore district, northern Junggar, China: Petrogenesis and tectonic implications[J]. Lithos, 2014, 190/191: 85-103. DOI URL

样品号	SiO₂		TiO₂		Al₂O₃		FeO		$\mathrm{Fe}_{2} \mathrm{O}_{3}{ }^{\mathrm{T}}$		MnO		CaO		MgO		K₂O		Na₂O		P₂O₅		烧失量		总量		K₂O+ Na₂O		Na₂O/ K₂O		Mg^#		La			Ce
JMT14-2	46.6		0.95		17.50		4.79		12.32		0.13		10.40		3.72		1.69		3.22		0.65		1.85		99.03		4.91		1.91		29.50		8.9			19.1
JMT14-3	42.9		1.04		15.35		6.52		15.00		0.22		10.85		6.41		2.61		1.64		0.69		1.93		99.64		4.25		0.63		37.19		8.0			18.5
JMT14-4	39.5		1.45		8.77		8.61		21.08		0.31		15.45		8.82		0.37		0.68		1.02		2.11		99.56		1.05		1.84		36.70		10.9			26.7
JMT14-5	42.4		1.14		14.00		7.10		16.52		0.25		11.75		7.01		2.41		1.42		0.77		2.12		99.79		3.83		0.59		37.02		9.5			23.2
JMT14-6	39.9		1.40		9.70		8.15		20.62		0.31		14.90		8.49		0.42		0.79		0.99		2.03		99.55		1.21		1.88		36.33		10.9			25.9
样品号	Pr		Nd		Sm		Eu		Gd		Tb		Dy		Ho		Er		Tm		Yb		Lu		∑REE		LREE/ HREE		(La/ Sm)_N		(Gd/ Yb)_N		(La/ Yb)_N			δEu
JMT14-2	2.38		10.4		2.52		0.94		2.99		0.42		2.32		0.51		1.30		0.18		1.29		0.20		223.06		2.00		2.28		1.92		4.95			1.05
JMT14-3	2.62		12.2		3.23		1.09		3.75		0.61		3.38		0.65		1.94		0.25		1.63		0.22		256.72		1.59		1.60		1.90		3.52			0.96
JMT14-4	3.81		17.7		5.18		1.47		5.79		0.86		5.16		1.04		3.04		0.41		2.57		0.40		382.00		1.46		1.36		1.86		3.04			0.82
JMT14-5	3.24		15.9		4.56		1.32		4.94		0.74		4.52		0.88		2.65		0.32		2.18		0.32		329.86		1.52		1.34		1.87		3.13			0.85
JMT14-6	3.79		18.0		5.20		1.40		6.08		0.90		5.31		1.08		2.83		0.41		2.54		0.35		380.41		1.45		1.35		1.98		3.08			0.76
样品号	Y	Sr		Rb		Ba		Th		U		Cr		Ta		Nb		Zr		Hf		Cu		Pb		Zn		V		Ni		Co		Ga	Sc
JMT14-2	13.1	712		43.5		347		1.32		0.64		40		0.2		2.2		50		1.4		69.8		4.5		62		417		28.1		32		7.18	20.7
JMT14-2	13.1	712		43.5		347		1.32		0.64		40		0.2		2.2		50		1.4		69.8		4.5		62		417		28.1		32		7.18	20.7
JMT14-4	27	451		6.1		66.6		0.94		0.5		50		0.1		2.6		45		1.5		77.6		4.2		108		788		27.8		62.4		10.25	57.1
JMT14-5	23.4	684		84.8		533		0.54		0.27		40		0.1		2.1		31		1.2		101		4.7		97		662		21.3		49		7.92	40.9
JMT14-6	27.1	530		8.3		106		0.92		0.42		50		0.1		2.6		43		1.6		49.5		4.4		107		784		25.6		61.2		9.93	54.3

样品号	SiO₂		TiO₂		Al₂O₃		FeO		$\mathrm{Fe}_{2} \mathrm{O}_{3}{ }^{\mathrm{T}}$		MnO		CaO		MgO		K₂O		Na₂O		P₂O₅		烧失量		总量		K₂O+ Na₂O		Na₂O/ K₂O		Mg^#		La			Ce
JMT14-2	46.6		0.95		17.50		4.79		12.32		0.13		10.40		3.72		1.69		3.22		0.65		1.85		99.03		4.91		1.91		29.50		8.9			19.1
JMT14-3	42.9		1.04		15.35		6.52		15.00		0.22		10.85		6.41		2.61		1.64		0.69		1.93		99.64		4.25		0.63		37.19		8.0			18.5
JMT14-4	39.5		1.45		8.77		8.61		21.08		0.31		15.45		8.82		0.37		0.68		1.02		2.11		99.56		1.05		1.84		36.70		10.9			26.7
JMT14-5	42.4		1.14		14.00		7.10		16.52		0.25		11.75		7.01		2.41		1.42		0.77		2.12		99.79		3.83		0.59		37.02		9.5			23.2
JMT14-6	39.9		1.40		9.70		8.15		20.62		0.31		14.90		8.49		0.42		0.79		0.99		2.03		99.55		1.21		1.88		36.33		10.9			25.9
样品号	Pr		Nd		Sm		Eu		Gd		Tb		Dy		Ho		Er		Tm		Yb		Lu		∑REE		LREE/ HREE		(La/ Sm)_N		(Gd/ Yb)_N		(La/ Yb)_N			δEu
JMT14-2	2.38		10.4		2.52		0.94		2.99		0.42		2.32		0.51		1.30		0.18		1.29		0.20		223.06		2.00		2.28		1.92		4.95			1.05
JMT14-3	2.62		12.2		3.23		1.09		3.75		0.61		3.38		0.65		1.94		0.25		1.63		0.22		256.72		1.59		1.60		1.90		3.52			0.96
JMT14-4	3.81		17.7		5.18		1.47		5.79		0.86		5.16		1.04		3.04		0.41		2.57		0.40		382.00		1.46		1.36		1.86		3.04			0.82
JMT14-5	3.24		15.9		4.56		1.32		4.94		0.74		4.52		0.88		2.65		0.32		2.18		0.32		329.86		1.52		1.34		1.87		3.13			0.85
JMT14-6	3.79		18.0		5.20		1.40		6.08		0.90		5.31		1.08		2.83		0.41		2.54		0.35		380.41		1.45		1.35		1.98		3.08			0.76
样品号	Y	Sr		Rb		Ba		Th		U		Cr		Ta		Nb		Zr		Hf		Cu		Pb		Zn		V		Ni		Co		Ga	Sc
JMT14-2	13.1	712		43.5		347		1.32		0.64		40		0.2		2.2		50		1.4		69.8		4.5		62		417		28.1		32		7.18	20.7
JMT14-2	13.1	712		43.5		347		1.32		0.64		40		0.2		2.2		50		1.4		69.8		4.5		62		417		28.1		32		7.18	20.7
JMT14-4	27	451		6.1		66.6		0.94		0.5		50		0.1		2.6		45		1.5		77.6		4.2		108		788		27.8		62.4		10.25	57.1
JMT14-5	23.4	684		84.8		533		0.54		0.27		40		0.1		2.1		31		1.2		101		4.7		97		662		21.3		49		7.92	40.9
JMT14-6	27.1	530		8.3		106		0.92		0.42		50		0.1		2.6		43		1.6		49.5		4.4		107		784		25.6		61.2		9.93	54.3