Zircon U-Pb age and petrogenesis of ore-bearing granitoid for the Chigou Cu-Mo deposit from the Zhashan basin, Shaanxi Province
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摘要:
秦岭造山带柞山盆地多处发育与晚中生代中酸性小岩体有关的铜钼矿床(点)，最近在池沟深部发现了厚大的斑岩型铜矿体，但对这些小岩体的形成时代和成因的研究很少。本文选择池沟地区不同类型的花岗质岩石开展地球化学特征和锆石U-Pb测年的研究。结果表明：该区小岩体主要为闪长岩、石英闪长岩和斑状花岗岩，它们为钾质钙碱性Ⅰ型花岗质岩石。矿物学、地球化学和Sr-Nd同位素特征均暗示它们是上地幔和下地壳同熔的深熔岩浆产物。与成矿密切相关的含矿岩体LA-MC-ICPMS锆石U-Pb谐和年龄为~145Ma，结合区域地质资料和成岩成矿关系的研究，认为池沟含矿岩体形成于晚侏罗世-早白垩世，柞水盆地存在一期重要的晚侏罗世-早白垩世中酸性岩浆岩和相应的斑岩-矽卡岩铜钼金矿化，与华北地块南缘晚中生代岩体和相关的钼铅锌矿床形成于同一地质事件。
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关键词:
- LA-MC-ICPMS锆石U-Pb年龄 /
- 斑岩铜矿床 /
- 池沟地区 /
- 柞山盆地
Abstract:There have plenty of Cu-Mo deposits (occurrences) which are genetically associated with intermediate-acid granitoid stock from the Zhashan basin in the Qinling Orogenic Belt, recently huge copper orebody has been discovered in the Chigou Cu-Mo deposit region, but the timing and petrogenesis of ore-bearing granitoids were poorly constrained. In this contribution, ore-bearing granitoids for the Chigou Cu-Mo deposit were selected; geochemistry and LA-MC-ICPMS zircon U-Pb data for these rocks have been carried out. They are dominantly quartz diorite, diorite and porphyritic granite in petrology, and geochemically belong to high potassic calc-alkaline I-type granitoid, geochemical and Sr-Nd isotopic evidence demonstrate that these rocks originated from partial melting of upper mantle and lower crust. The weight average 206Pb/238U ages for these ore-bearing granitoids are ~145Ma. In combined with regional geological characteristics and relation between igneous rocks and mineralization, it is proposed that the Chigou ore-bearing igneous rocks were formed during the Late Jurassic-Early Cretaceous time, and it is indicated that there have regional Late Jurassic-Early Cretaceous granitoid and porphyry-skarn Cu-Mo ploymetallic deposits in the Zhashan basin, synchronously the formation of granitoid batholith or stock and the corresponding porphyry Mo-hydrothermal vein Zn-Pb-Ag deposits in South margin of North China Craton.
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Key words:
- LA-MC-ICPMS zircon U-Pb age /
- Porphyry Cu-Mo deposit /
- Chigou region /
- Zhashan basin
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图 1
东秦岭花岗岩分布简图(底图据卢欣祥等，2000修改)
Figure 1.
Sketch granitoid map of the Eastern Qinling(after Lu et al.，2000)
图 3
柞山盆地池沟铜钼矿区13线剖面地质简图，显示采样位置(据任涛等，2009修改)
Figure 3.
Geological map of No. 13 cross section from the Chigou Cu-Mo deposit in the Zhashan basin，Shaanxi Province，showing the location of sample(modified after Ren et al.，2009)
图 4
柞山盆地池沟地区岩体的SiO2-K2O 图解(底图据Rollinson，1993)
Figure 4.
K2O versus SiO2 diagram for Late Mesozoic granitoids for the Chigou Cu-Mo deposit in the Zhashan basin，Shaanxi Province(modified after Rollinson，1993)
图 5
柞山盆地池沟地区岩体的稀土元素球粒陨石标准化图解(a，据Boynton，1984)和微量元素原始地幔标准化蛛网图解(b，据Sun and McDonough，1989)
Figure 5.
Chondrite-normalized REE patterns(a，after Boynton，1984)and PM-normalized incompatible element spider diagrams(b，after Sun and McDonough，1989)of the ore-bearing igneous rocks for the Chigou Cu-Mo deposit in the Zhashan basin，Shaanxi Province
图 6
柞山盆地池沟铜钼矿区含矿岩体中锆石的阴极发光和透射光照片，图中标出各测点年龄
Figure 6.
Transltion light microscope and cathodoluminescence images of the ore-bearing igneous rocks for the Chigou Cu-Mo deposit in the Zhashan basin，Shaanxi Province，showing the age of each analysis
图 7
柞山盆地池沟铜钼矿区含矿岩体中的锆石U-Pb谐和图解
Figure 7.
Zircon U-Pb dating results of the ore-bearing igneous rocks for the Chigou Cu-Mo deposit in the Zhashan basin，Shaanxi Province
图 8
柞山盆地池沟铜矿区含矿岩体的显微照片
Figure 8.
Microscope picture of the ore-bearing igneous rocks for the Chigou Cu-Mo deposit in the Zhashan basin，Shaanxi Province
表 1
柞山盆地池沟铜钼矿区岩体的主量(wt%)、微量和稀土元素(×10-6)的成分
Table 1.
Major(wt%)and trace element(×10-6)compositions of granitoids from the Chigou Cu-Mo deposit in the Zhashan basin，Shaanxi Province
样品号 201-60 SG20 CG7 CG6 CG8 CG3 1302-9 1301-40 位置 1号岩体 2号岩体 3号岩体 4号岩体 5号岩体 6号岩体 13线深部 13线深部 岩性 斑状花岗岩 闪长岩 石英闪长岩 石英闪长岩 石英闪长岩 闪长岩 石英闪长岩 石英闪长岩 SiO2 69.07 58.01 62.67 60.50 65.78 58.61 62.22 62.29 TiO2 0.37 0.84 0.67 0.75 0.50 0.73 0.57 0.65 Al2O3 14.29 16.20 16.46 16.23 16.44 16.23 15.18 16.25 FeOT 2.42 7.29 4.39 5.33 2.33 6.64 4.49 4.96 MnO 0.04 0.12 0.05 0.07 0.03 0.19 0.05 0.06 MgO 0.90 3.39 2.25 3.00 1.23 2.50 1.92 2.28 CaO 2.00 5.10 2.46 3.99 2.63 4.53 3.53 3.19 Na2O 3.32 3.96 3.91 3.53 3.64 4.84 3.69 3.83 K2O 4.50 2.92 3.46 3.13 5.11 3.90 3.48 3.48 P2O5 0.21 0.50 0.45 0.51 0.33 0.51 0.37 0.44 LOI 1.49 1.14 1.73 2.30 1.24 0.78 3.84 1.76 Ba 5450 2890 3490 3370 3490 3240 3130 3570 Pb 18.0 12.0 13.0 12.0 14.0 31.0 11.0 14.0 Cs 1.37 2.83 2.84 2.09 4.43 2.96 3.08 2.26 Rb 63.5 75.7 107 81.8 152 124 119 101 Sr 1070 1230 1260 1270 1115 1160 1190 1325 Th 19.05 12.05 15.4 13.4 21.0 14.4 17.3 15.05 U 1.58 1.86 3.48 2.77 4.2 1.97 4.6 2.94 Ta 0.90 0.90 1.00 1.00 1.10 1.00 1.10 1.00 Nb 12.0 14.3 15.3 16.0 16.8 15.5 15.7 16.2 Zr 174 188 225 190 206 212 213 210 Hf 4.80 5.20 6.20 5.20 5.80 5.90 5.90 5.60 La 24.5 41.0 42.8 40.5 44.0 41.0 39.6 39.8 Ce 50.9 79.9 82.4 78.7 85.9 76.4 74.8 76.5 Pr 6.32 9.59 9.87 9.39 9.94 9.08 8.62 9.21 Nd 22.7 35.8 37.0 35.4 35.4 34.3 31.9 34.1 Sm 3.72 6.34 6.31 6.31 5.67 6.21 5.49 5.92 Eu 1.25 1.65 1.75 1.60 1.51 1.53 1.35 1.57 Gd 3.09 5.45 5.72 5.39 4.77 5.44 4.67 5.22 Tb 0.35 0.70 0.74 0.64 0.58 0.7 0.58 0.64 Dy 1.74 3.81 3.94 3.34 2.89 3.61 3.03 3.33 Ho 0.320 0.690 0.740 0.600 0.510 0.680 0.550 0.570 Er 0.94 2.07 2.26 1.78 1.72 2.1 1.71 1.84 Tm 0.11 0.27 0.28 0.22 0.2 0.26 0.22 0.23 Yb 0.93 1.94 2.07 1.58 1.64 1.95 1.65 1.74 Lu 0.150 0.310 0.320 0.240 0.25 0.300 0.260 0.270 Y 9.30 19.7 21.1 17.8 15.5 19.8 16.0 17.6 87Rb/86Sr 0.172 0.178 0.245 0.186 0.394 0.308 0.289 0.221 87Sr / 86Sr 0.705194 0.705248 0.705573 0.705462 0.70601 0.705674 0.705632 0.705541 2sigma 15 6 9 18 13 10 11 14 (87Sr/ 86Sr)i 0.7049 0.7049 0.7051 0.7051 0.7052 0.7051 0.7051 0.7051 147Sm/144Nd 0.099 0.107 0.103 0.108 0.097 0.109 0.104 0.105 143Nd/144Nd 0.512308 0.512326 0.512297 0.512261 0.512222 0.512243 0.512251 0.512256 2sigma 12 4 8 7 25 12 12 8 εNd(t) -4.7 -4.5 -5.0 -5.8 -6.3 -6.1 -5.9 -5.8 注：(87Sr/86Sr)CHUR0=0.7045，(87Rb/86Sr)CHUR0=0.0827，(147Sm/144Nd)CHUR0=0.1967，(143Nd/144Nd)CHUR0=0.512638; λRb=1.42×10-11/a，λSm=6.5×10-12/a，t=140Ma 
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表 2
柞山盆地池沟铜矿区含矿岩体的LA-MC-ICPMS锆石U-Pb测年结果
Table 2.
LA-mc-ICPMS zircon U-Pb analysis data of the ore-bearing igneous rocks for the Chigou Gu deposit in the Zhashan basin , Shaanxi Province
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Boynton WV. 1984. Cosmochemistry of the rare earth elements: Meteorite studies. In: Henderson P (ed.). Rare Earth Element Geochemistry. Amsterdam, Oxford, New York, Tokyo: Elsevier, 63-114
Chen LH and Zhang WM. 2007. Metallogenic factors and potential of porphyry copper (molybdenum) deposits in the Shuangyuangou-Chigou area, Shannxi Province. Geology and Prospecting, 43(5):6-10(in Chinese with English abstract)
Gong HJ, Zhu LM, Sun BY, Li B and Guo B. 2009. Zircon U-Pb age and Hf isotope characteristics and their geological significance of the Shahewan, Caoping and Zhashui granitic pluton at the southern margin of North China Craton: Implications for geodynamics setting. Acta Petrologica Sinica, 25(2): 248-264 (in Chinese with English abstract)
Gradstein FM, Ogg JG, Smith AG, Bleeker W and Lourens LJ. 2004. A new geologic time scale, with special reference to Precambrian to Neogene. Episodes, 27:83-100
Guo B, Zhu LM, Li B, Gong HJ and Wang JQ. 2009. Zircon U-Pb age and Hf isotope composition of the Huashan and Heyu granite plutons at the southern margin of North China Craton: Implications for geodynamics setting. Acta Petrologica Sinica, 25(2): 265-281 (in Chinese with English abstract)
Hou KJ, Li YH and Tian YR. 2009. In situ U-Pb zircon dating using laser ablation-multi ion counting-ICP-MS. Mineral Deposits, 28: 481-492 (in Chinese with English abstract)
Liu YS, Hu ZC, Gao S, Gunther D, Xu J, Gao C and Chen H. 2008. In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard. Chemical Geology, 257: 34-43
Lu XX. 2000. Granitoid Tectonic Map of Qinling Belt. Xi’an: Xi’an Carographic Publishing House (in Chinese)
Lu XX, Yu ZP, Feng YL, Wang YT, Ma WF and Cui HF. 2002. Mineralization and tectonic setting of deep-hypabyssal granites in East Qinling Mountain. Mineral Deposits, 21: 168-177(in Chinese with English abstract)
Mao JW, Zhang ZC, Zhang ZH and Du AD. 1999. Rhenium-osmium isotopic dating of molybdenite in the Xiaoliugou W (Mo) deposit in North Qilian Mountains and its geological significance. Geochemica et Cosmochemica Acta, 63:1815-1818 doi: 10.1016/S0016-7037(99)00165-9
Mao JW, Xie GQ, Bierlein F, Ye HS, Qü WJ, Du AD, Pirajno F, Li HM, Guo BJ, Li YF and Yang ZQ. 2008. Tectonic implications from Re-Os dating of Mesozoic molybdenum deposits in the East Qinling-Dabie Orogenic Belt. Geochiminica et Cosmochiminica Acta, 72: 4607-4626 doi: 10.1016/j.gca.2008.06.027
Mao JW, Xie GQ, Pirajno F, Ye HS, Wang YB, Li YF, Xiang JF and Zhao HJ. 2010. Late Jurassic-Early Cretaceous granitoid magmatism in Eastern Qinling, central-eastern China: SHRIMP zircon U-Pb ages and tectonic implications. Australian Journal of Earth Sciences, 57: 51-78 doi: 10.1080/08120090903416203
Nasdala L, Hofmeister W, Norberg N, Martinson JM, Corfu F, Dörr W, Kamo SL, Kennedy AK, Kronz A, Reiners PW, Frei D, Kosler J, Wan YS, Götze J, Häger T, Kröner A and Valley JW. 2008. Zircon M257: A homogeneous natural reference material for the Ion microprobe U-Pb analysis of zircon. Geostandards and Geoanalytical Research, 32:247-265 doi: 10.1111/ggr.2008.32.issue-3
Niu BG, He ZJ, Ren JS, Wang J and Deng P. 2006. SHRIMP U-Pb ages of zircons from the intrusions in the western Douling-Xiaomaoling uplift and their Geological significances. Geological Review, 52: 826-835(in Chinese with English abstract)
Qin KZ, Zhang LC, Ding KS, Xu YX, Tang DM, Xu XW, Ma TL and Li GM. 2009. Mineralization type, petrogenesis of ore-bearing intrusions and mineralogical characteristics of Sanchakou copper deposits in eastern Tianshan. Acta Petrologica Sinica, 25:845-861(in Chinese with English abstract)
Ren T, Wang RT, Wang XY Xia CL and Guo YH. 2009. A way and method for prospecting copper deposit in the Zhashui-Shanyang sedimentary basin in the Qinling Orogenic Belt. Acta Geologica Sinica, 83: 1730-1738(in Chinese with English abstract)
Rollison HR. 1993. Using Geochemical Data: Evaluation, Presentation, Interpretation. New York: Longman Scientific and Technical, 1-352
Rui ZY, Zhang LS, Chen ZY, Wang LS, Liu YL and Wang YT. 2004. Approach on source rocks or source region of porphyry copper deposits. Acta Petrologica Sinica, 20:229-238(in Chinese with English abstract)
Slama J, Kosler J, Condon DJ, Crowley JL, Gerdes A, Hanchar JM, Horstwood MSA, Morris GA, Nasdala L, Norberg N, Schaltegger U, Schoene B, Tubrett MN and Whitehouse MJ. 2008. Plesovice zircon: A new natural reference material for U-Pb and Hf isotopic microanalysis. Chemical Geology, 249: 1-35 doi: 10.1016/j.chemgeo.2007.11.005
Sun SS and McDonough WF. 1989. Chemical and isotopic systematic basalt: Implication for mantle composition and processes. In: Saunders AD and Norry MJ (eds.). Magmatism in Oceanic Basins. Geological Society, Special Publication, 42: 313-345
Wang DS, Wang RT, Dai JZ, Wang CA, Li JH and Chen LX. 2009. “Dual ore controlling factors” characteristics of metallic deposits in the Qinling Orogenic Belt. Acta Geologica Sinica, 83: 1719-1729(in Chinese with English abstract)
Wang RT, Li JB, Ren T, Yang ZH, Mao JW and Wang T. 2008. Metallogenic conditions and prospecting potential of the Zhashui-Shanyang poly-metal ore cluster. Geology in China, 35:1291-1298(in Chinese with English abstract)
Wang YJ, Fan WM, Peng TP and Guo F. 2005. Elemental and Sr-Nd isotopic systematics of the Early Mesozoic volcanic sequence in southern Jiangxi Province, South China: Petrogenesis and tectonic implications. International Journal of Earth Sciences (Geol. Rundsch), 94: 53-65 doi: 10.1007/s00531-004-0441-4
Wan YW. 1980. Mineralization characteristics and ore deposit model of intermediate-acid granitoid porphyry from Shangyang region. Regional Characteristics of Qinling, (3):1-36(in Chinese)
Wang ZQ, Yan QR, Yan Z, Wang T, Jiang CF, Gao LD, Li QG, Cheng JL, Zhang YL, Liu P, Xie CL and Xiang ZJ. 2009. New division of the main tectonic units of the Qinling Orogenic Belt, Central China. Acta Geologica Sinica, 83: 1527-1546 (in Chinese with English abstract)
Yan Z et al. 1985. Granite from Shaanxi Province. Xi’an: Xi’an Jiaotong University Press, 1-321(in Chinese)
Zhang BR, Chen DX, Li ZJ, Gu XM, Jiang JY, Hu YK, Li FL, Guo WY and Li YC. 1989. Region Geochemistry of Shanyang-Zhashui Metallogenic Belt, Shaanxi Province. Wuhan: Press of China University of Geosciences,1-221(in Chinese with English abstract)
Zhang GW, Zhang BR, Ruan XC et al. 2001. Qinling Orogenic Belt and Continental Dynamics. Beijing: Science Press, 1-855(in Chinese with English abstract)
Zhang YL. 1992. Geological features and the metallogentic conditions of acid-intermediate acid small rock bodies in Xiaohekou area of Shangyang County, Shaanxi Province. Shaanxi Geology, 20(2):27-38(in Chinese with English abstract)
Zhu LM, Zhang GW, Guo B and Li B. 2008. U-Pb (LA-ICP-MS) zircon dating for the large Jinduicheng porphyry Mo deposit in the East China, and its metallogenic setting. Acta Geologica Sinica, 82: 204-220 (in Chinese with English abstract)
陈连红, 张卫敏. 2007.陕西省双元沟-池沟地区斑岩型铜(钼)矿成矿条件与远景分析. 地质与勘探, 43(5):6-10 http://www.cnki.com.cn/Article/CJFDTOTAL-DZKT200705003.htm
弓虎军, 朱赖民, 孙博亚, 李犇, 郭波. 2009. 南秦岭沙河湾、曹坪和柞水岩体锆石U-Pb年龄、Hf同位素特征及其地质意义. 岩石学报, 25(2): 248-264 http://www.ysxb.ac.cn/ysxb/ch/reader/view_abstract.aspx?flag=1&file_no=20090202&journal_id=ysxb
郭波, 朱赖民, 李犇, 弓虎军, 王建其. 2009. 华北陆块南缘华山和合峪花岗岩岩体锆石U-Pb年龄、Hf同位素组成与成岩动力学背景. 岩石学报, 25(2): 265-281 http://www.ysxb.ac.cn/ysxb/ch/reader/view_abstract.aspx?flag=1&file_no=20090203&journal_id=ysxb
侯可军,李延河,田有荣. 2009. LA-MC-ICP-MS锆石微区原位U-Pb定年技术. 矿床地质,28:481-492 http://www.cnki.com.cn/Article/CJFDTOTAL-KCDZ200904009.htm
卢欣祥, 肖庆辉, 董有. 2000.秦岭花岗岩大地构造图. 西安:西安地图出版社
卢欣祥, 于在平, 冯有利, 王义天, 马维峰, 崔海峰. 2002. 东秦岭深源浅成型花岗岩的成矿作用及地质构造背景.矿床地质, 21:168-177 http://www.cnki.com.cn/Article/CJFDTOTAL-KCDZ200202011.htm
牛宝贵,和政军,任纪舜,王军,邓平. 2006. 秦岭地区陡岭-小茅岭隆起带西段几个岩体的SHRIMP锆石U-Pb测年及其地质意义.地质论评, 52: 826-835 http://www.cnki.com.cn/Article/CJFDTOTAL-DZLP200606017.htm
秦克章,张连昌,丁奎首,许英霞,唐冬梅,徐兴旺,马天林,李光明. 2009. 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. 岩石学报, 25: 845-861 http://www.ysxb.ac.cn/ysxb/ch/reader/view_abstract.aspx?flag=1&file_no=20090410&journal_id=ysxb
任涛, 王瑞廷, 王向阳, 夏长玲, 郭延辉. 2009. 秦岭造山带柞水-山阳沉积盆地铜矿勘查思路与方法.地质学报, 83: 1730-1738 http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200911017.htm
芮宗瑶,张立生,陈振宇,王龙生,刘玉琳,王义天. 2004. 斑岩铜矿的源岩或源区探讨. 岩石学报, 20: 229-238 http://www.ysxb.ac.cn/ysxb/ch/reader/view_abstract.aspx?flag=1&file_no=20040223&journal_id=ysxb
万义文.1980.山阳一带中酸性斑岩体的成矿特点与成矿模式.秦岭区测, (3):1-36
王东生, 王瑞廷, 代军治, 王长安, 李建华, 陈荔湘. 2009. 秦岭造山带金属矿床的“二元控矿”特征.地质学报, 83: 1719-1729 http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200911016.htm
王瑞廷, 李剑斌, 任涛, 杨智慧, 毛景文, 王涛. 2008. 柞水-山阳多金属矿集区成矿条件及找矿潜力分析. 中国地质, 35:1291-1298 http://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200806027.htm
王宗起, 闫全人, 闫臻, 王涛, 姜春发, 高联达, 李秋根, 陈隽璐, 张英利, 刘平, 谢春林, 向忠金. 2009. 秦岭造山带主要大地构造单元的新划分. 地质学报, 83:1527-1546 http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200911003.htm
严阵等.1985. 陕西省花岗岩.西安:西安交通大学出版社,1-321
张本仁, 陈德兴, 李泽九, 谷晓明, 蒋敬业, 胡以铿, 李方林, 郭五寅, 李耀成. 1989. 陕西柞水山阳成矿带区域地球化学.武汉:中国地质大学出版社,1-221
张国伟, 张本仁, 袁学诚等. 2001. 秦岭造山带与大陆动力学. 北京: 科学出版社,1-855
张银龙. 1992. 陕西省山阳县小河口地区酸性-中酸性岩体地质特征及其成矿地质条件分析. 陕西地质, 20(2):27-38
朱赖民, 张国伟, 郭波, 李犇. 2008. 东秦岭金堆城大型斑岩钼矿床LA-ICP-MS锆石U-Pb定年及成矿动力学背景.地质学报, 82: 204-220 http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200802006.htm
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