新疆准噶尔北缘加玛特金铜矿区辉长岩锆石U-Pb年龄、岩石地球化学特征及地质意义

现代地质 ›› 2017, Vol. 31 ›› Issue (04): 651-661.

新疆准噶尔北缘加玛特金铜矿区辉长岩锆石U-Pb年龄、岩石地球化学特征及地质意义

李远友¹(), 刘国仁²^,³(), 于秀斌⁴, 李彦⁵, 祁世军³, 李强⁶, 金建斌³

1.山东省第四地质矿产勘查院,山东潍坊 261021
2.中国科学院新疆生态与地理研究所,新疆乌鲁木齐 830011
3.新疆维吾尔自治区地质矿产研究所,新疆乌鲁木齐 830001
4.中国冶金地质总局第一地质勘查院,河北三河 065201
5.河北省地矿局探矿技术研究院,河北三河 065201
6.中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点实验室,北京 100037

收稿日期:2016-05-22 修回日期:2016-12-28 出版日期:2017-08-10 发布日期:2017-09-15
通讯作者: 刘国仁,男,教授级高级工程师,博士,1965年出生,矿产普查与勘探专业,从事矿产勘查及成矿预测研究。Email: 467355307@qq.com。
作者简介:李远友,男,高级工程师, 1963年出生,矿产普查与勘探专业,从事矿产勘查及区域地质研究工作。Emai:liyuanyou2008@163.com。
基金资助:
新疆维吾尔自治区天山英才培养工程项目;新疆维吾尔自治区2014年国家高层次人才特殊支持计划项目;国土资源公益性行业科研专项经费项目(201211073)

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

LI Yuanyou¹(), LIU Guoren²^,³(), YU Xiubin⁴, LI Yan⁵, QI Shijun³, LI Qiang⁶, JIN Jianbin³

1. The No.4 Institute of Geology and Mineral Exploration of Shandong Province, Weifang, Shandong 261021, China
2. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, China
3. Xinjiang Uygur Autonomous Region Institute of Geology for Mineral Resources, Urumqi, Xinjiang 830001, China
4. The First Geological Institute of China Metallurgical Geology Bureau, Sanhe, Hebei 065201, China
5. Institute of Prospecting Technology Research of Hebei Bureau of Geology, Sanhe, Hebei 065201, China
6. Key Laboratory of Metallogeny and Mineral Assessment of Ministry of Land and Resources, Institute of Mineral Resources,Chinese Academy of Geological Sciences, Beijing 100037, China

Received:2016-05-22 Revised:2016-12-28 Online:2017-08-10 Published:2017-09-15

摘要/Abstract

摘要：

加玛特金铜矿位于准噶尔北缘,矿体赋存于辉长岩与北塔山组玄武岩接触带、石英闪长岩及其接触带,矿体呈脉状和透镜状,成矿与辉长岩和石英闪长岩有关。围岩蚀变主要有绿帘石化、黑云母化、绿泥石化、碳酸盐化、磁铁矿化。获得辉长岩锆石LA-ICP-MS U-Pb年龄为380 Ma,限定金铜矿化略晚于380 Ma。辉长岩的Th、Nb、Ta、Ti、Nd和Zr呈负异常,Rb、K、Pb和P为正异常,LREE表现为相对富集的右倾型分布模式和弱负铕异常到无铕异常,表明辉长岩为中泥盆世俯冲消减环境的产物,形成于岛弧环境。原始岩浆来源于受俯冲物质交代的地幔楔和软流圈的混合体,岩浆经历了一定程度的演化,并受到弱的地壳物质混染。

关键词: 辉长岩, 地球化学, 锆石U-Pb年龄, 加玛特矿区, 新疆准噶尔北缘

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

中图分类号:

P588.12

李远友, 刘国仁, 于秀斌, 李彦, 祁世军, 李强, 金建斌. 新疆准噶尔北缘加玛特金铜矿区辉长岩锆石U-Pb年龄、岩石地球化学特征及地质意义[J]. 现代地质, 2017, 31(04): 651-661.

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.

图/表 10

图1 加玛特金铜矿区域地质矿产图(据新疆地质矿产勘查与开发局第四地质大队资料修改) 1.第四系;2.下石炭统姜巴斯套组;3.中泥盆统北塔山组;4.下泥盆统托让格库都克组;5.二长花岗岩;6.钾长花岗岩;7.辉长岩;8.石英二长岩;9.石英闪长岩;10.晚石炭世二长花岗岩;11.晚石炭世石英闪长岩;12.地质界线;13.岩相界线;14.压扭性断裂;15.平移断裂;16.性质不明断裂;17.背斜;18.复式向斜;19.矿床(点)及编号:①托库特拜金矿床;②托斯巴斯套铁铜矿床;③托斯巴斯套南金矿点;④加玛特金铜矿床;⑤哈旦孙铁矿床

Fig.1 Regional geologic and mineral map of the Jiamate Cu-Au deposit

图2 加玛特金铜矿区地质略图(据新疆地质矿产勘查开发局第四地质大队资料修改,2014)

Fig.2 Simplified geologic map of the Jiamate Cu-Au deposit

图3 金铜矿化及辉长岩显微照片 A.金铜矿化;B.辉长岩;Amp.角闪石;Cpx.普通辉石;Pl.斜长石;Bi.黑云母

Fig.3 Photomicrographs of the gold-copper mineralization and gabbro

图4 加玛特金铜矿区辉长岩锆石LA-ICP-MS U-Pb年龄

Fig.4 Zircon LA-ICP-MS U-Pb age of the gabbro in the Jiamate Au-Cu ore district

表1 加玛特金铜矿区辉长岩LA-ICP-MS 锆石 U-Pb 年龄测定结果

Table 1 LA-ICP-MS U-Pb data of zircons from the gabbro in the Jiamate Au-Cu ore district

表2 加玛特矿区辉长岩主量元素(%)、稀土元素(10-6)和微量元素(10-6)化学成分

Table 2 Chemical compositions of major elements (%), trace elements (10-6) and rare earth elements (10-6) of the gabbro from the Jiamate ore district

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

表2 加玛特矿区辉长岩主量元素(%)、稀土元素(10-6)和微量元素(10-6)化学成分

Table 2 Chemical compositions of major elements (%), trace elements (10-6) and rare earth elements (10-6) of the gabbro from the Jiamate ore district

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

图5 加玛特矿区辉长岩硅-碱图解(底图据WILSON[9])

Fig.5 SiO2-(Na2O+K2O) diagram for gabbro in the Jiamate ore district (Base map after WILSON[9])

图6 加玛特矿区辉长岩稀土元素球粒陨石标准化曲线(球粒陨石数据据Sun和McDonough[10])

Fig.6 Chondrite-normalized REE patterns of the gabbro from the Jiamate ore district (Chondrite content from Sun and McDonough[10])

图7 加玛特矿区辉长岩微量元素蛛网图(原始地幔数据取自Sun和McDonough[10])

Fig.7 Primitive mantle-normalized trace element spider diagrams of the gabbro from the Jiamate ore district (Primitive mantle data after Sun and McDonough[10])

图8 加玛特辉长岩和老山口矿区侵入岩的Rb-(Y+Nb)、Nb-Y和Rb-(Yb+Ta)图解(底图据Pearce等[31];老山口数据据吕书君等[5]

Fig.8 Rb-(Y+Nb), Nb-Y and Rb-(Yb+Ta) diagrams of the gabbro from Jiamate and intrusive rocks from Laoshankou ore district(base map after Pearce et al. [31];Data of the Laoshankou from Lü et al.[5]

参考文献 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