Processing math: 66%
  • 中文核心期刊
  • 中国科技核心期刊
  • 中国科学引文数据库核心期刊

湘东北七宝山铜多金属矿床成矿时代及成矿物质来源——石英脉Rb-Sr定年和S-Pb同位素组成

胡俊良, 陈娇霞, 徐德明, 吴昌雄, 张鲲, 刘劲松, 刘阿睢, 刘重

胡俊良, 陈娇霞, 徐德明, 吴昌雄, 张鲲, 刘劲松, 刘阿睢, 刘重. 2017: 湘东北七宝山铜多金属矿床成矿时代及成矿物质来源——石英脉Rb-Sr定年和S-Pb同位素组成. 地质通报, 36(5): 857-866.
引用本文: 胡俊良, 陈娇霞, 徐德明, 吴昌雄, 张鲲, 刘劲松, 刘阿睢, 刘重. 2017: 湘东北七宝山铜多金属矿床成矿时代及成矿物质来源——石英脉Rb-Sr定年和S-Pb同位素组成. 地质通报, 36(5): 857-866.
HU Junliang, CHEN Jiaoxia, XU Deming, WU Changxiong, ZHANG Kun, LIU Jinsong, LIU Asui, LIU Chongpeng. 2017: Age and sources of the ore-forming material for the Qibaoshan Cu-polymetallic deposit in Hu'nan Province:Evidence from quartz vein Rb-Sr isotopic dating and S-Pb iso-topes. Geological Bulletin of China, 36(5): 857-866.
Citation: HU Junliang, CHEN Jiaoxia, XU Deming, WU Changxiong, ZHANG Kun, LIU Jinsong, LIU Asui, LIU Chongpeng. 2017: Age and sources of the ore-forming material for the Qibaoshan Cu-polymetallic deposit in Hu'nan Province:Evidence from quartz vein Rb-Sr isotopic dating and S-Pb iso-topes. Geological Bulletin of China, 36(5): 857-866.

湘东北七宝山铜多金属矿床成矿时代及成矿物质来源——石英脉Rb-Sr定年和S-Pb同位素组成

基金项目: 

中国地质调查局项目《钦杭成矿带(西段)重要金属矿床成矿规律及找矿方向研究》 1212011085405

《钦杭成矿带西段资源远景调查评价》 12120113067200

《湖北木子店—安徽吴家店地区矿产地质调查》 12120113068000

详细信息
    作者简介:

    胡俊良(1982-), 男, 硕士, 高级工程师, 从事矿床地球化学研究。E-mail:hjl1982da@163.com

  • 中图分类号: P597;P618.41

Age and sources of the ore-forming material for the Qibaoshan Cu-polymetallic deposit in Hu'nan Province:Evidence from quartz vein Rb-Sr isotopic dating and S-Pb iso-topes

  • 摘要:

    湘东北七宝山铜多金属矿床位于钦杭成矿带西段,是湘东北规模最大的铜多金属矿床。对七宝山矿床含矿石英脉中的石英矿物进行Rb-Sr同位素年龄测定,获得的Rb-Sr等时线年龄为153.4±2.0Ma(MSWD=1.8),87Sr/86Sr初始值为0.71849±0.00026,与区内石英斑岩形成年龄(153~155Ma)相同,说明七宝山铜多金属矿床成因与石英斑岩体密不可分,成岩成矿年龄均在燕山期。为分析七宝山矿床成矿物质来源,对矿区内的黄铁矿进行了S、Pb同位素分析,矿石δ34S为3.24‰~4.84‰,平均值为4.198‰;岩体δ34S为2.22‰~3.86‰,平均值为2.805‰。δ34S值总体变化较小,岩体δ34S值较矿石小,更趋近于0值,说明岩体中硫极可能源于地幔;而矿床中硫来源于主体地幔硫和少量地壳硫混熔的混合硫源。Pb同位素变化范围也较小,矿石206Pb/204Pb值变化范围为18.315~18.396,平均值为18.359;207Pb/204Pb值变化范围为15.629~15.737,平均值为15.675;208Pb/204Pb值变化范围为38.376~38.856,平均值为38.609。矿化岩体数值与之相似,结果显示,七宝山铜多金属矿床的Pb同位素组成具有下地壳富钍(铅)贫铀(铅)的特点。据此提出,矿床的成矿物质主要来自与含矿斑岩体有联系的深部岩浆分异演化而析出的含矿气-液流体。含矿斑岩体定位-结晶时,通过对周围受热地下水的对流循环作用,可以从围岩中萃取少量成矿物质加入成矿作用。

    Abstract:

    The Qibaoshan Cu-polymetallic deposit, located in the west section of the Qinzhou-Hangzhou metallogenic belt, is the largest Cu-polymetallic deposit in northeastern Hu'nan Province.However, the data of the deposit age are very insufficient.Based on quartz minerals Rb-Sr isotopic dating of the Qibaoshan deposit, the authors tried to obtain the age.The results show that the Rb-Sr isochron age is 153.4±2.0Ma (MSWD=1.8), initial 87Sr/86Sr=0.71849±0.00026, nearly identical with the quartz porphyry (153Ma to 155Ma) in the ore district in age, which suggests that the genesis of the Qibaoshan deposit was closely related to the quartz porphy-ry.The diagenesis and mineralization were both in the Yanshan period.The authors analyzed S, Pb isotope data of the pyrite to iden-tify the mineral sources of the Qibaoshan Cu-polymetallic deposit and obtained the following data:δ34S=3.24‰~4.84‰ for the ore, with an average of 4.198‰; δ34S=2.22‰~3.86‰ for the rock, with an average of 2.805‰.The δ34S values change overall in a small range, and the δ34S values of the rock change even in a smaller range, more close to the value of 0, which suggests that the sul-fur in the rock was most possibly derived from the mantle; and the sulfur in the ore came from the main mantle mixed with a small amount of crustal sulfur.The changes of lead isotopes are also in small ranges:206Pb/204Pb change in the range of 18.315~18.396 for the ore, with an average of 18.359;207Pb/204Pb change in the range of 15.629~15.737, with an average of 15.675;208Pb/204Pb change in the range of 38.376~38.856, with an average of 38.609.The values for the rock change in a similar range.These data show that lead isotope composition of the Qibaoshan Cu-polymetallic deposit has a lower crust (thorium-rich and uranium-depleted) characteris-tics.A comprehensive analysis of the Sr-S-Pb isotopic system of the Qibaoshan deposit indicates that the ore-forming material was derived from the ore gas-liquid fluid, resulting from the deep magma evolution and differentiation in the same evolution process as the quartz porphyry.At the same time, the host rock might have extracted a small amount of minerals from the wall rock to take part in the mineralization process through the circulating convection effect of heating groundwater, resulting in quartz porphyry intrusion and crystallization.

  • 龙木错-双湖-澜沧江碰撞结合带的存在与否一直存在争议[1-4],李才[1]认为,龙木错-双湖-澜沧江结合带是南羌塘地块与北羌塘-昌都地块之间的一条重要的碰撞结合带,但对该结合带形成时代的认识有较大的差异[1, 4-7]。澜沧江岩浆岩带沿澜沧江结合带呈带状分布,如临沧花岗岩、东达山花岗岩、纽多花岗岩和吉塘复式花岗岩。研究区大地构造位置处于羌北-昌都地块、双湖-澜沧江结合带和羌塘左贡地块的交会部位(图 1-a),区域大地构造位置独特,构造演化复杂。吉塘复式花岗岩体分布于昌都芒康盆地与类乌齐-左贡陆缘山盆之间,南东角与俄让-竹卡岩浆弧相邻,为北澜沧江结合带的重要组成部分(图 1-b)。北澜沧江结合带出露新元古界吉塘岩群(Pt3J)、下古生界酉西群(Pz1Y)、下石炭统卡贡组(C1kg)和卡贡岩组(C1k),被中—晚三叠世中酸性岩浆岩破坏严重,吉塘岩群多以残留体形式出现,两侧以上三叠统—侏罗系碎屑岩为主。吉塘复式花岗岩具有弱糜棱岩化、碎裂岩化,研究其成因及年代学,有助于解秘澜沧江花岗岩带的形成时代,分析澜沧江结合带的闭合时限。基于此,本文在对出露于澜沧江岩浆岩带北段的吉塘复式花岗岩进行野外地质调查的基础上,开展了吉塘复式花岗岩中黑云母二长花岗岩和花岗闪长岩的全岩组成、锆石U-Pb年龄研究,进而分析吉塘复式花岗岩的形成时代,为进一步研究澜沧江岩浆岩带和澜沧江结合带提供重要依据。

    图  1  图 1 研究区大地构造位置图(a)和区域地质简图(b)
    1—上三叠统-侏罗系碎屑岩;2—上三叠统碎屑岩;3—上三叠统竹卡组安山岩、岩屑凝灰岩;4—下石炭统卡贡组变质砂岩、千枚岩;5—下石炭统卡贡岩组变质砂岩、千枚岩夹大理岩、玄武岩岩块;6—下石炭统邦达岩组+错绒沟口岩组变质砂岩、千枚岩;7—下古生界酉西群;8—新元古界吉塘岩群;9—古-中元古界卡穷岩群;10—晚白垩世二长花岗岩、似斑状二长花岗岩;11—早侏罗世二长花岗岩、似斑状钾长花岗岩;12—晚三叠世花岗闪长岩;13—晚三叠世二长花岗岩;14—中三叠世二长花岗岩;15—中奥陶世二长花岗岩;16—晚寒武世石英闪长岩;17—区域次级断裂;18—区域分区断裂
    Figure  1.  Tectonic location of study area (a) and regional geological sketch map (b)

    吉塘复式花岗岩位于藏东察雅县吉塘镇以西约3km处,总体呈北西—南东向展布,侵位于新元古界吉塘岩群(Pt3J)变质岩系中,长约70km,宽2~ 10km,出露面积约340km2,该岩体为一复式岩体[7-8],主要由黑云母二长花岗岩和花岗闪长岩组成,在岩体边部,由于受到区域构造活动的影响,局部见碎裂岩化和糜棱岩化(图 2)。

    图  2  吉塘复式花岗岩地质简图
    C1kg—下石炭统卡贡组;Pz1Y—下古生界酉西群;Pt3J—新元古界吉塘岩群;γδT3—晚三叠世花岗闪长岩;ηγT3—晚三叠世二长花岗岩
    Figure  2.  Simplified geological map of Jitang duplex granites

    黑云母二长花岗岩:灰白色,具细-中粒半自形粒状结构,花岗结构,块状构造。矿物组成为石英(25% ~35%)、斜长石(30% ~40%)、碱性长石(20%~35%)、黑云母(10%~15%),以及少量锆石、榍石、绿泥石、磁铁矿、磷灰石等。斜长石呈无色,略浑浊,半自形长板状产出,粒径集中在2~5mm,次为0.5~2mm,发育聚片双晶,具明显的绢云母化。碱性长石呈半自形-他形板状,粒径多为2~ 4mm,次为0.5~2mm,具弱粘土化,发育条纹构造及格子状双晶。石英呈他形粒状,粒径0.3~ 2.2mm,少量为0.05~0.1mm,呈彼此镶嵌状分布于裂隙中。黑云母呈黄绿色,粒径0.5~2.5mm,多发育绿泥石或完全交代呈假象产出,偶见解理缝中未蚀变完全的棕色黑云母残余。锆石、榍石、磷灰石等呈自形柱状产出,总含量约2%。

    花岗闪长岩:灰白色,具细-中粒半自形粒状结构,块状构造。主要由石英(20%~25%)、斜长石(35% ~45%)、碱性长石(10% ~20%)、黑云母(10%~15%),以及少量锆石、榍石、绿泥石、磷灰石等组成。斜长石为更-中长石,粒径0.5~2mm;碱性长石主要为条纹长石,并出溶密集而狭窄的钠长石条带;黑云母呈棕色,绿泥石化,包含较多的副矿物包裹体。

    区内断裂构造发育,靠近断裂带附近,部分矿物发生破碎,但相对位移较小,可完整拼接,裂隙中主要充填了绢云母、黑云母及小颗粒石英,具有较明显的碎裂结构,形成了碎裂岩化二长花岗岩或碎裂岩化花岗闪长岩;更靠近断裂带一侧,由于受到的区域动力作用加强,部分区域形成了碎斑和碎基,矿物也有了一定的定向排列,形成了糜棱岩化二长花岗岩和糜棱岩化花岗闪长岩。

    吉塘复式花岗岩样品的主量、微量元素测试在川西北地质队检测中心完成。选取新鲜的具有代表性的岩石样品经薄片鉴定后送样,采用Optima 5300V等离子体发射光谱仪分析[9],分析精度优于5%,分析结果见表 1

    表  1  吉塘复式花岗岩主量、微量和稀土元素分析结果
    Table  1.  Whole-rock major, trace and rare erath element data of the Jitang duplex granites
    元素JT-1JT-2JT-3JT-4JT-5JT-6JT-7JT-8JT-9JT-10JT-11JT-12JT-13JT-14JT-15JT-16JT-17JT-18JT-19JT-20
    花岗闪长岩糜棱岩化花岗闪长岩碎裂岩化花岗闪长岩黑云母二长花岗岩糜棱岩化黑云母二长花岗岩碎裂岩化黑云母二长花岗岩
    SiO265.9264.7469.0667.2867.6669.5067.6066.4068.0068.7669.3868.9870.1671.0872.7070.7469.5072.6071.1275.16
    Al2O315.2315.9814.1414.0213.4613.3714.8714.8913.5114.3314.5313.5213.2412.9713.5213.0413.2113.2012.6912.26
    TFe2O34.694.714.034.514.484.885.074.775.093.842.964.012.934.273.704.524.983.393.732.37
    Na2O3.042.754.152.692.443.141.822.572.642.843.252.923.161.902.392.361.962.392.242.68
    K2O3.113.482.403.493.522.143.763.353.094.024.584.262.493.292.602.673.092.854.164.15
    CaO3.360.862.382.162.451.470.892.582.022.691.841.592.481.161.081.011.651.361.040.67
    MgO2.072.491.612.092.572.572.582.582.761.701.261.982.062.512.071.811.871.701.700.95
    MnO0.0660.0330.0420.0610.0650.0640.0510.1000.0460.0510.0470.0690.0290.0640.0440.0460.0650.0540.0590.040
    P2O50.280.510.200.210.190.140.250.270.170.110.190.120.110.100.100.190.100.0820.0930.10
    TiO20.760.620.550.700.750.750.700.730.800.640.460.710.920.610.520.640.590.420.510.41
    烧失量1.783.151.983.152.342.562.381.782.351.971.892.452.892.181.893.563.092.012.981.69
    H2O+1.623.061.862.962.222.382.281.542.101.781.762.282.642.081.783.462.801.802.661.66
    Na2O+K2O6.156.236.556.185.965.285.585.925.736.867.847.185.655.185.005.035.045.246.416.83
    Na2O/K2O0.980.791.730.770.691.470.480.770.850.710.710.691.270.580.920.890.630.840.540.65
    A/NK1.821.931.501.711.721.792.101.891.751.591.411.431.671.942.001.922.011.881.551.38
    A/CNK1.051.621.031.151.101.321.711.191.191.031.061.101.071.471.551.511.381.391.261.21
    AR1.992.172.312.232.202.102.102.032.172.352.842.812.122.162.042.122.032.122.753.24
    Li22.619.520.922.725.121.133.231.729.917.313.620.811.717.713.915.312.713.717.69.7
    Be0.962.153.563.213.945.224.203.362.023.023.492.692.563.238.132.374.155.148.422.11
    Sc10.311.09.310.811.510.714.917.813.811.09.212.014.414.410.111.612.812.19.75.8
    V86.589.058.572.178.186.794.496.794.870.143.672.179.571.555.663.071.655.962.519.4
    Cr37.736.426.643.282.369.680.952.690.333.024.553.261.675.850.061.673.748.549.011.3
    Co10.311.87.911.712.19.218.413.414.110.17.811.56.612.411.711.115.08.88.64.9
    Ni15.522.79.920.433.823.639.018.243.711.99.518.520.630.222.624.031.420.818.57.3
    Cu8.84.74.48.112.212.232.410.210.13.457.99.73.22.713.221.731.47.520.410.3
    Zn89.962.271.774.769.585.046.268.917961.841.075.918.759.652.160.994.451.666.048.6
    Ga20.524.120.121.219.119.722.722.819.618.121.817.821.818.817.717.517.517.217.515.0
    Rb18018812119921911221324815118125521232169119139159149195167
    Sr17085124173130149711641181621041252848593951098710555
    Zr13.2012.7011.3021.905.7717.3025.903.002.848.9546.4022.1014.302.965.574.356.2214.5015.9010.70
    Nb14.717.017.115.717.115.116.812.617.414.724.614.920.415.59.713.312.411.012.79.4
    Mo0.400.160.260.290.270.641.390.230.310.211.680.280.690.251.000.610.980.501.280.81
    Ba405416290810804412914674749113650982176.4664524577698543912430
    Hf0.570.170.511.070.530.500.590.130.120.231.020.830.370.120.140.120.200.150.620.18
    Ta2.142.021.571.801.161.101.391.441.230.781.860.841.120.820.860.980.740.931.010.68
    Pb47.719.841.556.222.429.418.130.876.217.227.639.59.1314.322.822.711.128.532.631.2
    Bi0.400.620.200.150.270.330.460.352.040.030.470.200.080.160.670.160.130.290.290.02
    Th2.63.523.722.024.311.720.711.415.510.026.729.324.210.016.916.814.116.318.417.1
    U3.552.762.234.054.422.874.072.342.281.414.792.382.251.593.493.342.702.054.462.05
    Y32.544.333.285.946.117.521.220.617.637.872.240.556.330.817.619.751.620.336.027.7
    La46.453.846.4106.054.137.841.641.338.248.6101.050.866.844.838.340.956.741.148.043.4
    Ce78.2106.085.5188.0101.075.679.381.175.790.2140.0100.0117.083.072.476.411579.389.383.3
    Pr2.573.748.8311.0011.108.789.326.219.368.779.8513.4015.205.738.169.068.968.889.946.20
    Nd11.215.934.443.145.234.738.925.134.034.640.950.156.622.632.935.834.933.935.422.5
    Sm2.634.336.4611.007.956.356.603.836.736.248.338.9910.204.185.806.256.426.166.594.81
    Eu1.110.711.011.421.311.391.261.021.511.290.761.122.110.830.901.091.230.831.060.57
    Gd2.544.556.1411.907.105.235.503.375.545.538.247.009.113.584.544.835.614.785.744.25
    Tb0.561.141.102.431.180.800.770.560.840.971.711.141.530.660.640.761.090.611.010.86
    Dy4.538.987.2817.007.936.334.443.464.546.6911.306.9610.704.333.215.477.803.526.725.82
    Ho0.901.671.273.121.430.650.760.580.711.162.031.281.970.830.510.711.530.621.151.03
    Er2.454.683.678.414.732.061.801.261.733.595.414.256.652.921.272.215.171.733.542.77
    Tm0.390.710.491.000.560.220.230.140.220.490.560.690.870.290.150.440.760.230.500.35
    Yb2.824.282.525.253.061.561.881.821.172.404.743.934.732.501.111.523.982.022.391.73
    Lu0.360.630.380.740.480.180.350.390.200.410.690.650.780.380.140.240.730.410.410.28
    ΣREE156.66210.89205.45409.89247.36181.73192.68170.20180.46210.88335.62250.67303.73176.64170.10185.68249.74184.07211.78177.89
    LREE142.09184.26182.60360.05220.88164.71176.95158.63165.49189.64300.94224.77267.42161.14158.53169.50223.07170.16190.33160.80
    HREE14.5726.6322.8549.8426.4817.0215.7311.5714.9621.2434.6825.8936.3215.5011.5816.1826.6713.9121.4517.09
    LREE/HREE9.756.927.997.228.349.6811.2513.7111.068.938.688.687.3610.4013.6910.488.3612.238.879.41
    LaN/YbN11.799.0113.1914.4612.6717.4415.8716.3023.3214.5215.269.2810.1312.8324.8119.2710.2114.5614.3918.02
    δEu1.290.480.480.380.520.720.620.850.730.660.280.420.650.640.520.580.610.450.520.37
    δCe1.151.300.971.090.960.980.951.110.950.990.870.920.861.090.960.931.130.970.951.10
    注:主量元素含量单位为%,微量和稀土元素含量单位为10-6
    下载: 导出CSV 
    | 显示表格

    锆石单矿物挑选、阴极发光图像拍摄均由武汉上谱分析科技有限责任公司完成。本文所测锆石具有明显的生长环带,在确定打点位置后送至武汉上谱分析科技有限责任公司进行测试。测试仪器为Agilent 7700e,GeolasPro激光剥蚀系统由COMPexPro 102 ArF 193nm准分子激光器和MicroLas光学系统组成,激光束斑直径和频率分别为32μm和5Hz。采用锆石标准91500和玻璃标准物质NIST610为外标分别进行同位素和微量元素分馏校正。对分析数据的离线处理采用软件ICPMSDataCal完成[10]。锆石U-Pb年龄谐和图绘制和年龄加权平均计算采用Isoplot/Ex_ver3完成[11]。锆石定年数据见表 2

    表  2  吉塘复式花岗岩LA-ICP-MS锆石U-Th-Pb分析结果
    Table  2.  LA-ICP-MS zircon U-Th-Pb analytical data of the Jitang duplex granites
    测点号PbThUTh/U同位素比值年龄/MaTi/10-6T/℃
    10-6207Pb/206Pb207Pb/235Pb206Pb/238Pb207Pb/206Pb207Pb/235Pb206Pb/238Pb
    D675花岗闪长岩
    D675-0122.01724.25930.290.05140.00180.23600.00790.03330.000325784.22156.52112.14.74724.2
    D675-0420.26742.05600.260.05030.00180.23040.00810.03330.000420981.52116.72112.75.76742.0
    D675-0728.39733.07240.410.05040.00150.23670.00730.03400.000421370.42166.02152.55.22733.0
    D675-1021.70689.25820.290.05050.00150.23310.00730.03330.000422070.42136.02112.43.16689.2
    D675-1712.06784.63140.360.05030.00240.23820.01140.03410.00042091142179.42162.88.92784.6
    D675-2215.53785.54050.430.05040.00200.23510.00990.03370.000621392.62148.12143.79.00785.5
    D675-2419.96738.15590.170.04970.00170.22830.00780.03320.000418979.62096.52112.45.51738.1
    D675-2627.73710.97010.400.04940.00210.23340.00800.03380.000416598.12136.62142.54.08710.9
    D675-0212.34797.83290.280.05140.00210.23580.00940.03330.000425794.42157.72112.310.15797.8
    D675-0317.55646.54610.310.05190.00190.24460.00910.03410.000428083.32227.42162.51.86646.5
    D675-056.57804.01660.550.05280.00360.24200.01500.03380.0005320158.322012.32143.310.77804.0
    D675-1111.06688.62950.250.04910.00200.22940.00920.03390.0005154101.02107.62152.83.14688.6
    D675-2122.66701.06220.180.04860.00150.22820.00700.03390.000412872.22095.82152.63.64701.0
    D675-1311.99881.13000.400.05210.00280.24620.01150.03400.0004300122.22249.42152.621.38881.1
    D675-0914.84790.23820.410.05300.00200.24740.00910.03380.000433285.22247.42142.69.42790.2
    D675-1225.88744.36830.320.05280.00150.24510.00670.03350.000332063.02235.52122.05.90744.3
    D675-089.06786.22320.480.04700.00240.21610.01070.03320.000450.1115.01999.02112.59.06786.2
    D675-1855.40640.214070.450.05340.00150.25220.00640.03400.000334661.12285.22152.21.71640.2
    D675-2316.19734.94250.370.05300.00180.24550.00800.03340.0004328106.02236.52122.35.33734.9
    D675-0638.06689.29850.280.05420.00150.25730.00680.03440.000338960.22335.52181.83.16689.2
    D675-1630.72645.27760.230.05340.00150.28260.01000.03780.000734663.02537.92394.41.82645.2
    D675-2579.37731.74540.080.10150.00202.51750.13790.17340.0080165437.0127739.8103144.05.15731.7
    D675-1927.44786.96150.350.07410.00210.37090.01080.03600.0004104358.23208.02282.39.13786.9
    D675-2047.28744.94230.090.13040.00422.05340.14180.10230.0051210351.1113347.262830.15.93744.9
    D675-1520.08766.32730.220.10960.00651.30130.13210.06680.00411792108.084658.341724.87.42766.3
    PM13/ZR黑云母二长花岗岩
    PM13/ZR-0933.15792.87680.540.05110.00150.25310.00720.03610.000425666.72295.92292.49.67792.8
    PM13/ZR-1424.97709.96400.300.05120.00160.24360.00800.03490.000425074.12216.52212.44.03709.9
    PM13/ZR-1733.01753.47910.570.05050.00150.24070.00690.03470.000421766.72195.72202.36.49753.4
    PM13/ZR-1847.62710.212000.250.05010.00210.24370.00990.03520.000319899.12218.12232.14.04710.2
    PM13/ZR-2030.56761.37310.470.05040.00150.24320.00720.03490.000421368.52215.92212.57.05761.3
    PM13/ZR-2176.22685.519750.150.04990.00100.24340.00520.03510.000319148.12214.22231.83.03685.5
    PM13/ZR-0824.04702.95920.430.04970.00160.24240.00820.03540.000418377.82206.72242.43.72702.9
    PM13/ZR-1538.15742.89730.300.04990.00140.23660.00670.03460.000319164.82165.52192.15.80742.8
    PM13/ZR-1952.40766.611580.720.04940.00140.24590.00710.03590.000316568.52235.82282.27.44766.6
    PM13/ZR-2337.16708.09320.200.04970.00140.24110.00670.03510.000318966.72195.52221.83.94708.0
    PM13/ZR-0252.72616.013630.250.04900.00120.23800.00620.03520.000414659.32175.12232.21.23616.0
    PM13/ZR-1117.18808.64050.590.05380.00210.25530.00990.03480.000336191.72318.02212.111.25808.6
    PM13/ZR-2543.13758.010440.460.05280.00160.25510.00820.03480.000431765.72316.62212.36.82758.0
    PM13/ZR-2468.40759.314290.840.05380.00150.26430.00660.03560.000436165.72385.32252.36.90759.3
    PM13/ZR-1040.40634.09730.360.05500.00160.27010.00740.03600.000441364.82436.02282.51.57634.0
    PM13/ZR-1322.65745.55580.300.05680.00210.27300.00970.03560.000548347.22457.82253.05.9745.5
    PM13/ZR-0428.76777.07200.510.04940.00150.22950.00700.03370.000316570.42105.82142.18.27777.0
    PM13/ZR-06256.00727.97870.630.09590.00163.40740.07690.25650.0040154631.5150617.7147220.64.93727.9
    PM13/ZR-1267.68781.23650.290.07490.00201.62470.04190.16000.0017106654.898016.29579.48.63781.2
    PM13/ZR-0345.30827.18790.960.15070.00720.86500.05250.03920.0007235381.063328.62484.313.36827.1
    D6082糜棱岩化花岗闪长岩
    D6082-0133.23707.78560.280.05170.00150.24230.00690.03310.000427263.92205.72102.33.93707.7
    D6082-17144.90785.737010.220.05250.00110.24890.00570.03430.000430954.62264.72172.39.02785.7
    D6082-0239.78866.59520.400.04890.00140.23570.00650.03490.000414366.72155.42212.418.90866.5
    D6082-0318.55777.54390.440.05270.00180.25560.00840.03510.000432275.92316.82222.48.32777.5
    D6082-0429.18743.27640.150.05210.00160.25250.00860.03490.000630072.22297.02213.55.83743.2
    D6082-0528.36745.77160.290.05190.00170.25020.00830.03480.000428071.32276.72212.75.99745.7
    D6082-0639.50772.19370.580.05290.00160.25510.00820.03480.000532468.52316.62202.97.88772.1
    D6082-0717.73806.04140.500.05060.00210.24670.00930.03550.000423396.32247.62252.510.98806.0
    D6082-0944.09693.310950.350.05040.00140.24450.00700.03510.000421366.72225.82222.33.32693.3
    D6082-1044.26711.710580.470.05180.00120.25110.00600.03510.000427653.72274.92222.24.12711.7
    D6082-1138.78730.69600.370.04890.00150.23190.00680.03430.000314670.42125.62172.15.09730.6
    D6082-1553.90791.312930.480.05070.00120.24010.00570.03440.000322857.42184.72181.89.53791.3
    D6082-1646.31669.710850.400.05300.00130.26110.00670.03560.000333257.42365.42262.22.50669.7
    D6082-1825.29780.35740.610.05190.00160.25330.00840.03530.000428072.22296.82232.78.55780.3
    D6082-1949.99666.912740.320.05090.00250.24380.01100.03500.0005239113.02229.02222.82.41666.9
    D6082-2020.81688.55600.040.05100.00140.24560.00810.03490.000723964.82236.62214.33.14688.5
    D6082-1247.80607.49930.530.05110.00140.27880.00760.03950.000425658.32506.02502.41.09607.4
    D6082-0854.50640.06590.350.05840.00130.57670.01730.07140.001654348.146211.24459.41.70640.0
    D6082-1452.82747.33960.240.07410.00161.42450.05800.13780.0046104343.789924.383226.06.09747.3
    D6082-1348.80682.92040.960.07380.00181.82010.04580.17870.0017103550.8105316.510609.32.94682.9
    下载: 导出CSV 
    | 显示表格

    本次分析了20件吉塘岩体样品的全岩主量和微量元素组成,分析结果见表 1。晚三叠世黑云母二长花岗岩地球化学特征显示:① SiO2含量为68.98%~75.16%,平均为71.14%,属于酸性岩类;② Na2O为1.90% ~3.25%,平均为2.53%,K2O为2.49%~2.58%,平均为3.41%,全碱(Na2O+K2O)为5.00% ~7.84%,平均为5.94%,Na2O/K2O值介于0.54~1.27之间,平均为0.77,属钙碱性-高钾钙碱性系列,在SiO2-K2O图解(图 3-a)中,样品投影点大部分落入高钾钙碱性系列范围,少数落在钙碱性系列与高钾钙碱性系列界线附近,总体体现高钾的特点;③ Al2O3含量为12.26% ~14.53%,平均为13.22%,A/CNK(铝饱和指数)值为1.06~1.55,平均为1.30,为过铝质花岗岩(图 3-b);④MgO含量为0.95%~2.51%,平均1.79%,显示较低的Mg含量;⑤含有较低的P2O5含量,为0.08%~0.19%,平均为0.12%,TiO2含量为0.41%~0.92%,平均为0.58%。

    图  3  吉塘复式花岗岩SiO2-K2O(a)和A/CNK-A/NK图解(b)
    Figure  3.  SiO2-K2O(a)and A/CNK-A/NK(b)plots of the Jitang duplex granites

    晚三叠世花岗闪长岩地球化学特征显示:① SiO2含量为64.74%~69.50%,平均为67.49%,属于酸性岩类;② Na2O含量为1.82% ~4.15%,平均为2.81%,K2O为2.14%~4.02%,平均为3.24%,全碱(Na2O + K2O)为5.28% ~6.86%,平均为6.04%,Na2O/K2O值为0.48~1.73,平均为0.92,属钙碱性-高钾钙碱性系列,在SiO2-K2O图解(图 3-a)中,样品投影点大部分落入高钾钙碱性系列范围内,少数落在钙碱性系列与高钾钙碱性系列界线附近,总体体现高钾的特点,与黑云母二长花岗岩相比,花岗闪长岩相对富钠;③Al2O3为13.37%~15.98%,平均为14.38%,A/CNK(铝饱和指数)值为1.03~1.71,平均为1.24,为过铝质花岗岩(图 3-b);④MgO含量为1.61%~2.76%,平均为2.30%,Mg含量较低;⑤较低的P2O5含量,为0.11%~0.51%,平均为0.23%,TiO2含量为0.55%~0.80%,平均为0.70%。

    根据上述2种岩石的地球化学特征可以得出,吉塘黑云母二长花岗岩和花岗闪长岩具有较一致的主量元素含量,其变化特征也具有一致性,间接反映这2类岩石可能为同一岩浆演化而来。

    吉塘复式花岗岩样品微量元素测试结果表明(表 1),晚三叠世黑云母二长花岗岩稀土元素总量∑REE(不含Y)=170.10×10-6~335.62×10-6,平均为224.59×10-6;轻稀土元素(LREE)为158.53×10-6~ 300.94×10-6,重稀土元素(HREE)为11.58×10-6~ 36.32×10-6,LREE/HREE值为7.36~13.69,具有较高的(La/Yb)N值,为9.28~24.81,平均为14.88。晚三叠世花岗闪长岩∑REE(不含Y)=156.66×10-6~ 409.89 ×10-6,平均216.62 ×10-6;LREE为142.09 ×10-6~360.05 ×10-6,HREE为11.57 ×10-6~49.84 ×10-6,LREE/HREE值为6.92~13.71,具有较高的(La/Yb)N值,为9.01~23.32,平均为14.86。上述2类岩石微量元素特征显示,轻、重稀土元素分异明显,球粒陨石标准化稀土元素配分曲线(图 4-ac)基本一致,表现为重稀土元素相对亏损、轻稀土元素强富集的右倾型,2类岩石样品均呈弱负Ce异常和强负Eu异常特征。微量元素原始地幔标准化蛛网图(图 4-bd)显示,花岗闪长岩和黑云母二长花岗岩也具有明显的一致性,表现出相似的分布曲线,可能反映了同源岩浆的特点。总体上,Nb、Ta、Zr、Hf等高场强元素相对亏损,Rb、K、Th、U等元素明显富集,Ba、Sr元素明显呈负异常,表明花岗岩岩浆部分熔融或结晶分异过程中有斜长石的分离。

    图  4  吉塘复式花岗岩稀土元素球粒陨石标准化配分图(a、c)和微量元素原始地幔标准化蛛网图(b、d)
    (标准化值据参考文献[12])
    Figure  4.  Chondrite-normalized REE patterns (a, c) and primitive mantle-normalized trace earth element patterns (b, d) of the Jitang duplex granites

    本文选取具有代表性的样品对吉塘复式岩体中的黑云母二长花岗岩、花岗闪长岩和糜棱岩化黑云母二长花岗岩进行LA-ICP-MS锆石U-Pb测年。用于分析测试的锆石颗粒自形程度高,形态多为长柱状,少量为短柱状,长轴150~300μm,长宽比为1.5:1~2.5:1。在阴极发光(CL)图像上,锆石颜色多数呈黑色或灰黑色,具有明显的生长环带,属于岩浆成因锆石。

    3件样品锆石U-Pb测年数据见表 2。PM13/ZR样品锆石的U含量为365×10-6~1975×10-6,Pb含量为17.18×10-6~255.97×10-6,Th含量为107×10-6~ 1244×10-6,Th/U值为0.15~1.40;D675样品锆石的U含量为166×10-6~1407×10-6,Pb含量为6.57×10-6~79.37×10-6,Th含量为38×10-6~632×10-6,Th/U值为0.08~0.55;D6082样品锆石的U含量为160 ×10-6~3701 ×10-6,Pb含量为17.73 ×10-6~ 144.87×10-6,Th含量为20×10-6~828×10-6,Th/U值为0.12~0.96。3件样品除个别锆石外,Th、U含量及Th/U值均显示为岩浆成因锆石[13]。按照Hoskin[14]提出的锆石类型投图方法显示,所选锆石为岩浆锆石。

    本次对PM13/ZR(黑云母二长花岗岩)样品的24颗锆石进行了24个测试点的LA-ICP-MS分析,分析结果见表 2。其中2个测点为继承锆石,分别与区域上吉塘岩群和酉西岩群中的碎屑锆石年龄一致;6个测点的普通Pb含量较高,置信度降低,故舍去;有16个测试点获得较一致的206Pb/238U年龄。206Pb/238U年龄在219~229Ma之间(表 2),在锆石U-Pb年龄谐和图(图 5)中,数据点分布较集中,反映了良好的谐和性,可以代表样品的结晶成岩年龄。16个测点的206Pb/238U年龄加权平均值为222.8±1.5Ma(MSWD=1.60,n=16),说明吉塘复式花岗岩中黑云母二长花岗岩的结晶年龄为222.8± 1.5Ma,属晚三叠世。

    图  5  吉塘复式花岗岩锆石U-Pb谐和图
    Figure  5.  The zircon U-Pb concordia diagrams of the Jitang duplex granites

    D675(花岗闪长岩)样品共分析了25个年龄测试点(表 2)。其中3个测点为继承锆石,分别与区域上吉塘岩群和酉西岩群中的碎屑锆石年龄一致;2个测试点的普通Pb含量较高且为高值点,故舍去;有20个测试点获得较一致的206Pb/238U年龄,206Pb/238U年龄在211~218Ma之间(表 2),在锆石U-Pb年龄谐和图(图 5)中,数据点分布较集中,反映了良好的谐和性,可以代表样品的结晶年龄。20个测点的206Pb/238U加权平均年龄值为213.6 ± 1.1Ma(MSWD=0.98,n=20),说明吉塘复式花岗岩中花岗闪长岩的结晶年龄为213.6±1.1Ma,属于晚三叠世。

    D6082(糜棱岩化花岗闪长岩)样品共分析了20个年龄测试点(表 2)。其中3个测点为继承锆石,分别为1060±9.3Ma、832±26.0Ma和445±9.4Ma,与区域上吉塘岩群和酉西岩群中的碎屑锆石年龄一致;有15个测试点获得较一致的206Pb/238U年龄,206Pb/238U年龄在217~226Ma之间(表 2),在锆石U-Pb年龄谐和图(图 5)中,数据点分布较集中,反映了良好的谐和性,可以代表样品的结晶年龄。15个测点的206Pb/238U年龄加权平均值为221.1±1.5Ma(MSWD=1.30,n=15),说明吉塘复式花岗岩中糜棱岩化花岗闪长岩的结晶年龄为221.1±1.5Ma,属于晚三叠世。

    本文对吉塘复式花岗岩的3件样品进行了LAICP-MS锆石U-Pb测年。阴极发光图像显示锆石以自形晶为主,具有明显的生长环带,含有较高的Th/U值,可以代表所测样品的结晶年龄。锆石UPb测年结果显示,吉塘复式花岗岩形成于213.6± 1.1~222.8±1.5Ma之间,即形成于晚三叠世。结合前人对澜沧江北段相邻区域纽多岩体、东达山岩体、吉塘岩体的测年成果,如樊炳良等[9]在纽多岩体中获得黑云母二长花岗岩的LA-ICP-MS锆石UPb年龄为243.6±1.4Ma,陈福忠等[8]使用全岩Rb-Sr等时线测年法分别在东达山岩体、吉塘复式岩体中获得219.6Ma和220Ma年龄值,澜沧江南部测年数据集中于210~245Ma之间,发现澜沧江南北两侧具有较一致的岩浆结晶年龄,可能暗示其具有相近的大地构造演化过程。

    Watson等[15]提出利用锆石中Ti含量估算锆石结晶时的岩浆温度,认为可以近似代表岩浆的最高温度,其精度可达10℃左右,称之为“锆石Ti温度计”。锆石Ti温度计的准确度受控于岩浆体系中SiO2和TiO2的活度,对于压力的变化并不灵敏[16]。锆石的化学式为ZrSiO4,Ti可以进入锆石替换Si形成独立变化相ZrTiO4和TiZrO4[17],在一定的压力下具有如下的变化形式:

    [lg(TiinZircon)+lgαSiO2lgαTiO2]=A+B/T

    Ferry等[16]计算出常数A、B的值,并确定其计算公式为:

    lg(TiinZircon)+lgαSiO2lgαTiO2=(5.711±0.072)(4800±86)/T(K)

    Ti和Si发生置换反应会导致晶体体积的变化,进而引起温度的变化,导致对锆石Ti温度计也有影响。Ferry等[16]认为,在中下地壳以上范围(压力小于1000MPa)内形成锆石时对其影响不大,可以忽略不计。本次研究测试样品为黑云母二长花岗岩和花岗闪长岩,均可明显见到石英存在,故取αSiO2≈1,典型的硅酸盐熔体中αTiO2活度一般为0.6,整理上述公式得出:

    \begin{array}{l} T\left( {℃} \right) = \left\{ {\left( {4800 \pm 86} \right)/\left[ {\left( {5.711 \pm 0.072} \right) - {\rm{lg}}\left( {{\rm{Ti}} - {\rm{in}} - {\rm{Zircon}}} \right)} \right.} \right.\\ \left. {\left. { - {\rm{lg\alpha Si}}{{\rm{O}}_{\rm{2}}}{\rm{lg\alpha Ti}}{{\rm{O}}_{\rm{2}}}} \right]} \right\} - 273 \end{array}

    吉塘复式花岗岩中黑云母二长花岗岩、花岗闪长岩和糜棱岩化花岗闪长岩均出现继承锆石,说明岩浆处于锆饱和状态,岩浆温度开始降低时就伴随着锆石的结晶,因此由上述公式计算出的温度可以代表岩浆的最高温度。吉塘复式花岗岩中黑云母二长花岗岩、花岗闪长岩和糜棱岩化花岗闪长岩的锆石Ti温度计计算结果见表 2。黑云母二长花岗岩中16颗锆石结晶温度在616.0~808.6℃之间,平均温度为742.9℃;花岗闪长岩中20颗锆石结晶温度在640.2~881.1℃之间,平均温度为755℃;糜棱岩化花岗闪长岩中15颗锆石结晶温度在666.9~ 866.5℃之间,平均温度为748.6℃。三者平均温度相差不大,可忽略不计,表明2类岩石具有相同或相近的熔融机制。

    吉塘复式花岗岩中黑云母二长花岗岩和花岗闪长岩的铝饱和指数较高,分别为1.06~1.55和1.03~1.71,总体大于1.05;Na2O/K2O值较低,平均值分别为0.77和0.92,Rb/Sr值较高,平均值分别为1.71和1.48,CaO平均含量分别为1.39%和2.09%,均小于3.7%;CIPW标准矿物含刚玉,平均值分别为3.14%和3.04%,均大于1%;根据20件样品主量和微量元素数据分析,均具有S型花岗岩的特征。在AC-F判别图(图 6)中,20件样品投影点均落入S型花岗岩区域。因此,吉塘复式花岗岩为过铝质高钾钙碱性S型花岗岩。

    图  6  吉塘复式花岗岩ACF成因类型判别图
    (底图据参考文献[18])
    Figure  6.  Plots of the Jitang duplex granites in ACF diagram for division of I- and S-type granites

    花岗岩中的部分微量元素在不同的矿物中含量存在较大的差异,Rb、Sr、Ba等微量元素多赋存于花岗岩类岩石的黑云母和长石中,因此,可以采用Rb-Sr-Ba系统判别岩石的源区成分[19]。在Al2O3/ TiO2-CaO/Na2O图解(图 7-a)中,吉塘复式花岗岩体中黑云母二长花岗岩和花岗闪长岩样品投点绝大多数落入变质杂砂岩熔融区;在Rb/Sr-Rb/Ba图解(图 7-b)中,吉塘复式花岗岩中黑云母二长花岗岩和花岗闪长岩样品投点均落入杂砂岩熔融区域,均暗示吉塘复式花岗岩的源岩可能变质杂砂岩。吉塘复式岩体中黑云母二长花岗岩和花岗闪长岩均强烈亏损Sr、Eu等元素,亏损Ba元素,指示岩体中斜长石、钾长石为熔融残留相矿物。此外,黑云母二长花岗岩和花岗闪长岩的Rb/Sr值分别为1.29~3.04(平均1.88)和0.75~3.00(平均1.48),Rb/Ba值分别为0.21~0.50(平均0.30)和0.16~0.45(平均0.31),指示吉塘复式岩体的源区为富斜长石的变质杂砂岩成分。

    图  7  吉塘复式花岗岩Al2O3/TiO2-CaO/Na2O(a)和Rb/Sr-Rb/Ba(b)图解
    (底图据参考文献[19])
    Figure  7.  Al2O3/TiO2-CaO/Na2O(a)and Rb/Sr-Rb/Ba(b)diagrams of the Jitang duplex granites

    Sylvester[19]认为,源区岩石的部分熔融与Al2O3/ TiO2值关系密切,认为Al2O3/TiO2>100时源区部分重熔温度小于875℃;当岩石中Al2O3/TiO2<100时,源区部分重熔温度大于875℃;且存在两者比值与温度呈负相关的特征。吉塘复式花岗岩中黑云母二长花岗岩和花岗闪长岩的Al2O3/TiO2值分别为14.39~31.63和16.97~25.83,均小于100,说明源区部分重熔的温度应大于875℃,这与吉塘复式花岗中不同岩石类型的锆石结晶温度介于616.0~ 881.1℃之间的结论吻合(表 2)。在推覆作用下, 地壳加厚均衡后的最高温度仅为750℃左右[7, 20],因此仅靠地壳加厚增温无法使源岩重熔,还需其他深部异常热流的作用才能发生部分重熔。结合区域构造演化过程,认为吉塘复式花岗岩的形成与碰撞造山导致地壳加厚增温有关,也与岩石圈剪切、伸展期有关的深熔作用相关。

    吉塘复式花岗岩中黑云母二长花岗岩和花岗闪长岩的岩石地球化学特征显示,吉塘复式花岗岩的形成与碰撞造山导致地壳加厚增温及与岩石圈剪切、伸展期有关的深熔作用有关,而与北澜沧江结合带的俯冲碰撞关系不大。在(Y+Nb)-Rb图解(图 8-a)和Hf-3Ta-Rb/30图解(图 8-b)中,黑云母二长花岗岩和花岗闪长岩样品投影点落入碰撞后-同碰撞或板内花岗岩环境,可能与元古宇吉塘岩群片麻岩有关[21]。England等[20]认为,地壳俯冲碰撞至地壳加厚直至部分熔融的演化过程持续时间较长,可以推测北澜沧江洋的闭合时间应早于211~ 229Ma。本文在吉塘复式花岗岩中获得的岩浆结晶年龄和岩石地球化学特征与临沧花岗岩特征基本一致,推测具有相近的大地构造演化过程,即存在统一的构造岩浆活动模式。王保弟等[4]明确指出,存在龙木错-双湖-澜沧江碰撞结合带,并以吉塘岩群中变质花岗岩为依据,获得246.3±0.8Ma的年龄,认为是北澜沧江结合带碰撞造山的产物,且在246Ma之前该带已经进入陆-陆碰撞阶段。陶琰等[7]在研究吉塘花岗岩的基础上提出澜沧江洋的闭合时间早于220Ma,可能为280Ma左右;祁生胜等[6]在吉塘岩群石榴子石白云母石英片岩中获得白云母Ar-Ar年龄为251.5±2.6Ma;笔者在吉塘岩群糜棱岩化片麻岩中获得一组LA-ICP-MS锆石U-Pb年龄介于252~273Ma之间(另文专述),认为与区域构造岩浆-变质变形事件有关。因此,笔者认为,北澜沧江洋的闭合时间可能在273Ma左右。此外,吉塘复式花岗岩侵位于吉塘岩群中,在吉塘岩群与吉塘复式花岗岩的接触部分发育大量的混染现象,指示吉塘复式花岗岩的源岩可能为吉塘岩群,且暗示其侵位深度较深。

    (1)吉塘复式花岗岩属于过铝质S型花岗岩,与临沧花岗岩、纽多花岗岩具有一致的岩石地球化学特征,为澜沧江花岗岩带的重要组成部分,具有统一的构造岩浆活动模式。吉塘复式花岗岩的源岩为变质杂砂岩,指示其源岩可能为吉塘岩群。

    (2)吉塘复式花岗岩的形成年龄介于213.6± 1.1~222.8±1.5Ma之间,为晚三叠世,与临沧花岗岩的主体形成时代一致,暗示具有统一的大地构造演化过程。

    (3)吉塘复式花岗岩的成因与碰撞造山导致的地壳加厚增温及与岩石圈剪切、伸展期有关的深熔作用有关,澜沧江洋的闭合时间可能为273Ma左右。

    致谢: 审稿专家对稿件提出了宝贵的修改意见,在此表示诚挚的谢意。
  • 图  1   七宝山铜多金属矿矿区地质简图

    1—矿体;2—地质界线;3—断层及编号;4—推测隐伏断层及编号;5—白云质灰岩/灰岩;6—石英砾岩;7—石英斑岩;8—花岗斑岩;C2+3ht—中上石炭统壶天群;C1d—下石炭统大塘阶;Z1l—震旦系莲沱组;Ptln—前震旦系冷家溪群;Oπ5Ⅰa—燕山早期第一次侵入石英斑岩;Oπ5Ⅰb—燕山早期第二次侵入石英斑岩;γπ—花岗斑岩

    Figure  1.   Geological sketch map of the Qibaoshan Cu-polymetallic deposit

    图  2   七宝山铜多金属矿床石英脉中石英矿物Rb-Sr等时线年龄

    Figure  2.   Rb-Sr isochron ages of fluid inclusions of quartz from the Qibaoshan Cu-polymetallic deposit

    图  3   七宝山铜多金属矿床δ34SCDT频数统计直方图

    Figure  3.   The distribution of δ34S values of the Qibaoshan Cu-polymetallic deposit

    图  4   七宝山铜多金属矿床Pb同位素模式图(底图据参考文献[43])

    Figure  4.   The Pb isotopic model for the Qibaoshan Cu-polymetallic deposit

    表  1   七宝山铜多金属矿床含矿石英脉中的石英矿物Rb-Sr同位素测定结果

    Table  1   Rb-Sr isotopic data of fluid inclusions in quartz mineral of the Qibaoshan Cu-polymetallic deposit

    样号 样品名称 Rb/10-6 Sr/10-6 87Rb/86Sr 87Sr/86Sr (87Sr/86Sr)i
    QB22-1 石英 1.335 0.4996 7.724 0.73554 0.00020 0.71863
    QB22-2 石英 0.622 0.3968 4.524 0.72829 0.00006 0.71839
    QB22-3 石英 1.004 0.4501 6.450 0.73254 0.00018 0.71842
    QB22-4 石英 1.143 0.3416 9.674 0.73945 0.00010 0.71827
    QB22-5 石英 2.408 0.4854 14.360 0.74981 0.00016 0.71837
    下载: 导出CSV

    表  2   七宝山铜多金属矿床硫化物的S同位素组成

    Table  2   Surfur isotopic composition of pyrite from the Qibaoshan Cu-polymetallic deposit

    编号 样品描述 采样位置 分析矿物 δ34SCDT/‰
    QB2 块状黄铁矿矿石 老虎口矿段40m中段之33m分段13线 黄铁矿 4.50
    QB4 块状黄铁矿磁铁矿矿石 老虎口矿段40m中段之33m分段93线 黄铁矿 4.11
    QB6 块状黄铁矿矿石 老虎口矿段40m中段之33m分段7线 黄铁矿 4.45
    QB6 块状黄铁矿矿石 老虎口矿段40m中段之33m分段7线 黄铁矿 4.68
    QB8 块状桁粒黄铁矿矿石 老虎口矿段40m中段5线 黄铁矿 4.29
    QB9 块状细粒黄铁矿矿石 老虎口矿段40m中段5线 黄铁矿 4.84
    QB12 含铜磁铁矿矿石 鸡公湾矿段80m中段12线 黄铁矿 3.24
    QB19 含铜黄铁矿矿石 大七宝山矿段146m矿段28线 黄铁矿 3.47
    QB1 黄铁矿化石英斑岩 老虎口矿段40m中段之33m分段13线 黄铁矿 2.84
    QB17 细脉侵染状黄铁矿化石英斑岩 大七宝山矿段80m矿段26线 黄铁矿 3.86
    QB20 闪锌矿化石英斑岩 大七宝山矿段146m矿段28线 黄铁矿 2.22
    QB20 闪锌矿化石英斑岩 大七宝山矿段146m矿段28线 黄铁矿 2.30
       注:主量元素含量单位为%,微量、稀土元素为10-6
    下载: 导出CSV

    表  3   七宝山铜多金属矿床硫化物的Pb同位素组成

    Table  3   Lead isotopic composition of pyrite from the Qibaoshan Cu-polymetallic deposit

    样品类型 分析矿物 分析结果
    样号 同位素比值 表面年龄/Ma φ μ Th/U 208Pb/(206Pb+207Pb)
    206Pb/204Pb 207Pb/204Pb 208Pb/204Pb
    QB2 黄铁矿 18.384±0.007 15.689±0.007 38.509±0.015 295 0.594 9.64 3.79 1.1302
    QB4 黄铁矿 18.315±0.002 15.661±0.002 38.376±0.005 310 0.596 9.59 3.77 1.1295
    QB6 矿石 黄铁矿 18.384±0.002 15.737±0.003 38.856±0.007 351 0.600 9.74 3.95 1.1388
    QB8 黄铁矿 18.326±0.006 15.665±0.004 38.632±0.015 307 0.596 9.6 3.87 1.1365
    QB12 黄铁矿 18.350±0.001 15.629±0.001 38.577±0.004 247 0.590 9.53 3.83 1.1353
    QB19 黄铁矿 18.396±0.003 15.666±0.003 38.705±0.008 258 0.591 9.6 3.87 1.1363
    QB1 黄铁矿 18.390±0.003 15.711±0.001 38.571±0.006 316 0.596 9.69 3.82 1.1311
    QB17 黄铁矿 18.318±0.004 15.652±0.003 38.569±0.01 297 0.595 9.58 3.85 1.1354
    QB20 黄铁矿 18.412±0.006 15.717±0.006 38.734±0.015 308 0.596 9.69 3.88 1.1349
    QB20 黄铁矿 18.373±0.007 15.707±0.006 38.728±0.016 324 0.597 9.68 3.89 1.1364
    下载: 导出CSV

    表  4   钦杭结合带主要斑岩相关铜矿床及其成岩成矿年龄

    Table  4   Porphyry-related copper deposits and their ages of diagenesis and mineralization in QHSZ, southern China

    序号 矿床名称 矿石种类 侵人体类型 侵人体年龄 成矿年龄 资料来源
    测试方法 年龄/Ma 测试方法 年龄/Ma
    1 德兴 Cu-Au-Mo 花岗闪长斑岩 锆石U-Pb 171±3 辉钼矿Re-Os 170.4±1.8 [30-31]
    2 永平 Cu-W-Mo 石英斑岩 锆石U-Pb 160±2.3
    135±7.4
    辉钼矿Re-Os 156.7±2.8
    155.7±3.6
    [32] [33]
    3 村前 Cu多金属 花岗斑岩 锆石U-Pb 169±1.1 [34]
    4 铜山岭 Cu多金属 花岗闪长斑岩 SHRIMP锆石U-Pb 149±4 [35]
    5 宝山 Cu-Mo-W 花岗闪长斑岩 锆石U-Pb 173±1.9 黄铁矿Rb-Sr 174±7 [4, 36]
    6 水口山 Cu多金属 花岗闪长斑岩 锆石U-Pb 172.3±1.6 [4]
    7 七宝山 Cu多金属 石英斑岩 锆石U-Pb 155~153 石英Rb-Sr 153.4±2.0 [23], 本文
    8 圆珠顶 Cu-Mo 花岗斑岩 SHRIMP锆石U-Pb 154±2
    153.4±1.6
    辉钼矿Re-Os 155±5 [37-38]
    下载: 导出CSV
  • 杨明桂, 黄水保, 楼法生, 等.中国东南陆区岩石圈结构与大规模成矿作用[J].中国地质, 2009, 36(3):528-543. http://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200903006.htm
    毛景文, 谢桂青, 郭春丽, 等.华南地区中生代主要金属矿床时空分布规律和成矿环境[J].高校地质学报, 2008, 14(4):510-526. http://www.cnki.com.cn/Article/CJFDTOTAL-GXDX200804007.htm
    毛景文, 陈懋弘, 袁顺达, 等.华南地区钦杭成矿带地质特征和矿床时空分布规律[J].地质学报, 2011, 85(5):636-658. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201105006.htm
    王岳军, 范蔚茗, 郭峰, 等.湘东南中生代花岗闪长岩锆石U-Pb法定年及其成因指示[J].中国科学(D辑), 2001, 31(9):745-751. http://www.cnki.com.cn/Article/CJFDTOTAL-JDXK200109005.htm
    陆玉梅, 殷浩然, 沈瑞锦.七宝山多金属矿床成因模式[J].矿床地质, 1984, 3(4):53-60. http://www.cnki.com.cn/Article/CJFDTOTAL-KCDZ198404006.htm
    沈瑞锦, 陆玉梅. 湖南七宝山多金属矿床成因模式[C]//钨家达. 湖南地学新进展. 长沙: 湖南科学技术出版社, 1996: 29-36.
    胡祥昭, 彭恩生, 孙振家.湘东北七宝山铜多金属矿床地质特征及成因探讨[J].大地构造与成矿学, 2000, 24(4):365-370. http://cdmd.cnki.com.cn/Article/CDMD-10533-2002080803.htm
    胡祥昭, 肖宪国, 杨中宝.七宝山花岗斑岩的地质地球化学特征[J].中南工业大学学报, 2002, 33(6):551-554. http://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD200206001.htm
    胡俊良, 徐德明, 张鲲.湖南七宝山石英斑岩地球化学特征及其与成矿的关系[J].华南地质与矿产, 2012, 28(4):298-306. http://www.cnki.com.cn/Article/CJFDTOTAL-HNKC201204002.htm
    刘姤群, 金维群, 张录秀, 等.湘东北斑岩型和热液脉型铜矿成矿物质来源探讨[J].华南地质与矿产, 2001, 17(1):40-47. http://www.cnki.com.cn/Article/CJFDTOTAL-HNKC200101005.htm
    李华芹, 陈富文, 蔡红.新疆西准噶尔地区不同类型金矿床RbSr同位素年代研究[J].地质学报, 2000, 74(2):181-192. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200002008.htm
    李华芹, 王登红, 陈富文, 等.湖南雪峰山地区铲子坪和大坪金矿成矿作用年代学研究[J].地质学报, 2008, 82(7):900-905. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200807007.htm
    蔡明海, 韩凤彬, 何龙清, 等.湘南新田岭白钨矿床He, Ar同位素特征及Rb-Sr测年[J].地球学报, 2008, 29(2):167-173. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXB200802007.htm
    付建明, 李华芹, 马丽艳, 等.粤北东昌市和尚田钨锡多金属矿成矿时代及其地质意义[J].地质学报, 2013, 87(9):1349-1358. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201309012.htm
    蔺志永, 王登红, 张长青.四川宁南跑马铅锌矿床的成矿时代及其地质意义[J].中国地质, 2010, 37(2):488-494. http://www.cnki.com.cn/Article/CJFDTOTAL-DIZI201002024.htm

    Faure G. Principle of Isotope Geology(2nd Edition)[M]. New York:John Wiley & Sons, 1986:183-199.

    胡俊良, 徐德明, 张鲲.湖南七宝山矿床石英斑岩锆石U-Pb定年及Hf同位素地球化学[J].矿床地质, 2014, 33(增刊):201-202. http://www.cnki.com.cn/Article/CJFDTOTAL-KCDZ2014S1103.htm
    李华芹, 刘家齐, 魏琳.热液矿床流体包裹体年代学研究及其地质应用[M].北京:地质出版社, 1993:1-27.
    李华芹.新疆北部有色金属矿床成矿作用年代学[M].北京:地质出版社, 1998.
    蔡应雄, 杨红梅, 段瑞春, 等.湘西-黔东下寒武统铅锌矿床流体包裹体和硫、铅、碳同位素地球化学特征[J].现代地质, 2014, 28(1):29-41. http://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ201401004.htm

    Qiu X F, Yang H M, Lu S S, et al. Geochronology and geochemis-try of Grenville-aged(1063±16Ma) metabasalts in the Shennongjia district, Yangtze block:implications for tectonic evolution of the South China Craton[J]. International Geology Review, 2015, 57:76-96. doi: 10.1080/00206814.2014.991949

    Ludwig K R. IsoplotEx v. 2.6[M]. Berkeley Geochronological Center Spec Publ. LA. 1999.

    胡俊良, 徐德明, 张鲲, 等.湖南七宝山铜多金属矿床石英斑岩时代与成因:锆石U-Pb定年及Hf同位素与稀土元素证据[J].大地构造与成矿学, 2016, 40(6):1196-1211. http://www.cnki.com.cn/Article/CJFDTOTAL-DGYK201606007.htm

    Norman D Z, Lands G P. Source of mineralizing components in hydrothermal ore fluids as evidenced by 87Sr/86Sr and stable isotope data from the Pasto Bueno Deposit, Peru[J]. Economical Geology, 1983, 78:451-456. doi: 10.2113/gsecongeo.78.3.451

    Rossman G R, Weis D, Wasserburg G J. Rb, Sr, Nd and Sm con-centrations in quartz[J]. Geochimica et Cosmochimica Acta, 1987, 51:2325-2329. doi: 10.1016/0016-7037(87)90286-9

    Changkakoti A, Gray J, Krstic D, et al. Determimations of radio-genic isotopes (Rb/Sr, Sm/Nd, and Pb/Pb) in fluid inclusion wa-ters:An example from the Bluebell Pb-Zn deposit, British Colum-bia, Canada[J]. Geochimica et Cosmochimica Acta, 1988, 52:961-967. doi: 10.1016/0016-7037(88)90251-7

    张理刚.稳定同位素在地质科学中的应用[M].西安:陕西科学技术出版社, 1985:152-185.
    郑永飞, 陈江峰.稳定同位素地球化学[M].北京:科学出版社, 2000:143-245.
    张长青, 李厚民, 代军治, 等.铅锌矿床中矿石铅同位素研究[J].矿床地质, 2006, 25(增刊):213-216. http://cpfd.cnki.com.cn/Article/CPFDTOTAL-ZGDJ200611003057.htm
    王强, 赵振华, 简平, 等.德兴花岗闪长斑岩SHRIMP锆石U-Pb年代学和Nd-Sr同位素地球化学[J].岩石学报, 2004, 20(2):315-324. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200402011.htm

    Lu J J, Hua R M, Yao C L. Re-Os age for molybdenite form the Dexing porphyry Cu-Au deposit in Jiangxi province, China[J]. Geochimica et Cosmochimica Acta, 2005, 69(Suppl. A):882. https://www.researchgate.net/publication/270455478_Multifractal_distribution_of_geochemical_elements_in_Dexing_porphyry_copper_deposit_Jiangxi_Province_China

    丁昕, 蒋少涌, 倪培, 等.江西武山和永平铜矿含矿花岗质岩体锆石SIMS U-Pb年代学[J].高校地质学报, 2005, 11(3):383-389. http://www.cnki.com.cn/Article/CJFDTOTAL-GXDX200503009.htm
    李晓峰, Yasushi W, 华仁民, 等.华南地区中生代Cu-(Mo)-WSn矿床成矿作用于洋岭/转换断层俯冲[J].地质学报, 2008, 82(5):625-640. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200805007.htm
    王强, 孙燕, 张雪辉, 等.江西省村前铜多金属矿床斜长花岗斑岩LA-ICP-MS锆石U-Pb年龄及地质意义[J].中国地质, 2012, 39(5):1143-1150. http://www.cnki.com.cn/Article/CJFDTOTAL-DIZI201205002.htm
    魏道芳, 鲍征宇, 付建明.湖南铜山岭花岗岩体的地球化学特征及锆石SHRIMP定年[J].大地构造与成矿学, 2007, 31(4):482-489. http://www.cnki.com.cn/Article/CJFDTOTAL-DGYK200704014.htm
    姚军明, 华仁民, 林锦富.湘南宝山矿床REE、Pb-S同位素地球化学及黄铁矿Rb-Sr同位素定年[J].地质学报, 2006, 80(7):1045-1054. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200607010.htm
    陈富文, 李华芹, 王登红, 等.粤西圆珠顶斑岩型铜钼矿床成矿地质特征及成岩成矿作用年代学研究[J].地质学报, 2012, 86(8):1298-1305. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201208013.htm
    陈懋弘, 李忠阳, 李菁, 等.初论广西大瑶山地区多期次花岗质岩浆活动与成矿系列[J].地学前缘, 2015, 22(2):41-53. http://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201502005.htm
    侯明兰, 蒋少涌, 姜耀辉, 等.胶东蓬莱金城矿区的S-Pb同位素地球化学和Rb-Sr同位素年代学研究[J].岩石学报, 2006, 22(10):2525-2533. doi: 10.3969/j.issn.1000-0569.2006.10.013
    路远发. GeoKit:一个用VBA构建的地球化学工具软件包[J].地球化学, 2004, 33(5):459-464. http://www.cnki.com.cn/Article/CJFDTOTAL-DQHX200405003.htm
    孙省利. 西秦岭泥盆系西城矿化集中区烃碱流体成矿系列研究[D]. 成都理工大学博士学位论文, 2001: 43-44.
    刘姤群, 杨世义, 张秀兰, 等.粤北大宝山多金属矿床成因的初步探讨[J].地质学报, 1985, 61(1):47-61. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE198501005.htm

    Zartman R E, Doe B R. Plumbotectonics-the model[J]. Tectono-physics, 1981, 75:135-162. doi: 10.1016/0040-1951(81)90213-4

    中国地质调查局资源评价部等. 钦杭成矿带重要矿产勘查部署方案. 2010.
  • 期刊类型引用(5)

    1. 张力文,罗拉次旺,樊炳良,布嘎次仁,周新,冯德新,郭伟康. 藏东吉塘群黑云二长片麻岩锆石U-Pb年龄及其变质时代的厘定. 地质通报. 2022(11): 1927-1941 . 本站查看
    2. 于涛,周新,樊炳良. 藏东吉塘地区吉塘岩群斜长角闪岩的时间序列:来自锆石LA-ICP-MS U-Pb年龄的证据. 高原科学研究. 2021(02): 13-26 . 百度学术
    3. 徐长昊,任飞,陆彪. 澜沧江结合带北段纽多细粒二长花岗岩成因与构造意义. 矿物学报. 2020(03): 237-247 . 百度学术
    4. 于涛,徐佳丽,高强,樊炳良,徐长昊. 藏东卡贡地区早侏罗世似斑状钾长花岗岩LA-ICP-MS锆石U-Pb年龄及地球化学特征. 地质通报. 2020(05): 621-630 . 本站查看
    5. 胡志宇,王新然,樊炳良,白涛. 藏东地区中奥陶世浪拉山糜棱岩化二长花岗岩LA-ICP-MS锆石U-Pb年代学及地质意义. 矿物岩石. 2019(03): 60-68 . 百度学术

    其他类型引用(3)

图(4)  /  表(4)
计量
  • 文章访问数:  2342
  • HTML全文浏览量:  245
  • PDF下载量:  382
  • 被引次数: 8
出版历程
  • 收稿日期:  2016-08-11
  • 修回日期:  2017-03-16
  • 网络出版日期:  2023-08-16
  • 刊出日期:  2017-04-30

目录

/

返回文章
返回