Basemental Attribution of the Fe-Cu-Au-W-Mo Polymetallic Ore Cluster in the Southeastern Hubei: Constraint from the Ages and Hf Isotopes of the Inherited Zircons
-
摘要:
长江中下游成矿带鄂东南矿集区的基底存在统一的川中式基底和北部川中式基底、南部江南式基底的争议。笔者对灵乡岩体西段闪长玢岩开展锆石U-Pb定年和Hf同位素分析,结果显示闪长玢岩的锆石具有复杂的组成与来源:最年轻的4颗锆石加权平均年龄为(141±4) Ma,结合前人测年结果推测其可作为闪长玢岩的成岩年龄;其余16颗锆石具有较为宽泛的年龄(217~
2550 Ma)和Hf同位素组成(εHf(t) = −11.2~11.7)。进一步结合前人获得的鄂东南矿集区岩浆岩继承锆石数据,分别对比川中式基底崆岭杂岩、江南式基底梵净山群及下江群的锆石数据,发现其与崆岭杂岩具有明显差异,但和梵净山群及下江群具有高度相似性。并且鄂东南矿集区岩浆岩继承锆石和梵净山群、下江群均记录了~1.5 Ga地壳增生事件。结合区域地球物理特征,笔者认为鄂东南矿集区南部为江南式基底,北部为川中式基底,两者的分界线大致为灵乡-大冶-网湖一线。Abstract:There are two different opinions about the basemental attribution of the ore cluster in the southeastern Hubei Province, Middle-Lower Yangtze Metallogenic Belt that all attributed to the Chuanzhong-type basement or the north part related to Chuanzhong-type basement and the south part classified to the Jiangnan-type basement. In this study, zircon U-Pb dating and Hf isotope analysis were conducted for diorite porphyrite in the western Lingxiang pluton. The results indicate that the zircons of diorite porphyrite show complex compositions and sources. The youngest four zircons yield a mean 206Pb/238U age of (141±4)Ma, which coincide with previous researches and interpreted as the crystallization age of the diorite porphyrite. In addition, The other 16 older zircons have varied ages (217~
2 550 Ma) and Hf isotopic compositions (εHf(t) = −11.2~11.7). Combined with the reported ages and εHf(t) values of inherited igneous zircons from the ore cluster in the southeastern Hubei, we compared with the data from Chuanzhong-type and Jiangnan-type basements respectively. The results suggest that they are different from Kongling Complex of the Chuanzhong-type basement, but are similar to the Fanjingshan and XiaJiang Groups of the Jiangnan-type basements. Particularly, the ~1.5 Ga crustal accretion both record in the ore cluster in the southeastern Hubei and the Fanjingshan and XiaJiang Groups. Combined with the regional geophysics, bounded by the line from Lingxiang, Daye to Wanghu Lake, the north part of ore cluster in the southeastern Hubei belong to Chuanzhong-type basement and the south part relate to Jiangnan-type basement. -
青藏高原的形成与演化经历了多个洋盆的闭合以及陆陆碰撞过程,由此形成了高原上多个近EW向延伸的构造缝合带,将青藏高原划分为多个次级地块(Zhu et al., 2011; Kapp et al., 2019)。其中,班公湖–怒江缝合带(以下简称班–怒带)横亘于青藏高原中部,是中生代班公湖–怒江特提斯洋(以下简称班-怒洋)构造演化的残迹,其EW向延伸达2 000 km以上,构成了拉萨地块与羌塘地块之间的地质界线(图1a)。
图 1 青藏高原构造单元划分图(a)、南羌塘地块中—晚侏罗世侵入岩展布图(b)、卡易错地区地质简图(c)1.第四系;2.上三叠统日干配错组;3.古新统—始新统牛堡组;4.中—晚侏罗世花岗岩;5. 构造岩快;6. 断层;7. 角度不整合;8. 湖泊;9. 采样点;10. 锆石U-Pb年龄(本文);11. 锆石U-Pb年龄(引用);JSSZ.金沙江缝合带;LSSZ.龙木措–双湖缝合带;BNSZ.班公湖–怒江缝合带;IYZSZ.印度–雅鲁藏布缝合带;LT.拉萨地块;SQ.南羌塘地块;NQ.北羌塘地块;年龄数据引自Li等(2014)、Liu等(2014)、Wu等(2016)、Sun等(2020)、Yang等(2021)Figure 1. (a) Tectonic subdivision of the Tibetan Plateau, (b) distribution of Middle-Late Jurassic intrusive rocks within Southern Qiangtang block and (c) simplified geological map of the Kayico area, Tibet中生代以来,受班–怒洋俯冲闭合过程的影响,在班–怒带上及其两侧发育了大规模的火山岩浆活动,这些多期次岩浆岩记录了洋盆开合过程的信息,是反演区域构造–岩浆演化的关键,为揭示班–怒洋俯冲闭合过程提供了重要约束(李永飞等, 2005; Zhu et al., 2011, 2016; Pan et al., 2012; Wu et al., 2016, 2019a, 2019b; 刘海永等, 2019; 吴浩等, 2020)。然而,尽管国内外学者先后在青藏高原中部开展了大量的地质研究工作,但是关于区域上中生代多期次、多样性岩浆活动的成因与深部动力学过程尚存有较大的争议,是众多学者关注的热点(Kapp et al., 2007; Pan et al., 2012; Zhu et al., 2016; Fan et al., 2017)。近年来,越来越多的岩浆岩研究资料表明羌塘地块的南缘出露着大规模的中—晚侏罗世岩浆岩(图1b),并显示复杂的地球化学组成,仅在中酸性侵入岩中就先后识别了普通钙碱性I型花岗岩、高分异型花岗岩、富Na埃达克岩与富K埃达克岩等岩石类型(Li et al., 2014; Wu et al., 2018)。然而,羌塘地块南缘中—晚侏罗世多样性岩石类型之间究竟有何成因联系、形成于何种构造环境、反映了怎样的深部动力学过程尚不明确,亟待进一步研究。不仅如此,尽管关于班-怒洋的闭合时限仍存有争议(Kapp et al., 2007; Wu et al., 2019b; Fan et al., 2021),但是当前的研究普遍认为青藏高原中部中-晚侏罗世岩浆岩形成于洋壳俯冲背景,是班–怒洋洋壳俯冲消减引发的弧型岩浆活动(Li et al., 2014; Wu et al., 2016, 2018)。因此,查明羌塘地块南缘中—晚侏罗世岩浆作用过程,不仅对认识班–怒洋构造演化史具有重要的指示意义,同时对探讨俯冲带弧型岩浆起源与演化、壳幔物质循环与交换过程同样具有重要的约束。
藏北卡易错地区发育着大规模的晚侏罗世酸性侵入岩,为揭示班-怒洋俯冲过程、探讨俯冲带复杂的构造–岩浆活动提供了理想的研究对象(图1b)。本次在详细野外地质调查工作的基础上,对藏北卡易错地区出露的花岗闪长岩体进行了系统的岩石学、地质年代学、地球化学和同位素的研究工作,以此确定花岗闪长岩的形成时代与岩石成因,进一步对比区域岩浆岩研究资料,共同约束区域构造–岩浆过程,为揭示班–怒洋俯冲过程、探讨青藏高原早期形成与演化史提供新的约束。
1. 地质背景与岩石学特征
研究表明青藏高原自中生代以来经历了多个地块的闭合、碰撞过程,由此形成了青藏高原上近EW向延伸的多个构造缝合带,并将青藏高原从北至南划分为可可西里–松潘–甘孜地块、北羌塘地块、南羌塘地块、拉萨地块和喜马拉雅地块等多个次级地块(Zhu et al., 2011; Kapp et al., 2019)(图1a)。其中,班-怒带夹持于南羌塘地块和拉萨地块之间,大量的岩浆岩在南羌塘地块的南缘出露着大规模的中-晚侏罗世岩浆岩,该期岩浆岩以中酸性侵入岩为主,具有持续时间长、地球化学组分多样的特征,为探讨青藏高原早期形成与演化过程提供了理想的研究对象。
本次研究区卡易错地区位于日土县NE方向约45 km,大地构造位置处于班-怒带以北、南羌塘地块的南缘。区内构造–地层格架近NW–SE向展布,其研究区西南部主要以上三叠统日干配错组(T3r)灰岩夹砂岩和古新统—始新统牛堡组(E1-2n)砂、砾岩为主;而研究区东北部主要以酸性侵入岩为主。此外,受构造作用的影响,区内出露着大量的灰岩和砾岩的构造岩块(图1c)。前人已经对区内花岗岩体进行了初步的年代学和地球化学的研究工作,研究认为卡易错岩体形成于中—晚侏罗世(168~160 Ma),其地球化学组成指示岩石类型以高分异型花岗岩为主,是古老的变火成岩地壳部分熔融并经历广泛结晶分异作用的产物(Li et al., 2014; Liu et al., 2014)。
本次研究的花岗闪长岩(E 80°6′25″;N 33°28′20″)呈岩株状侵入于构造岩块之中(图2a),出露规模长约为10 m、宽约为3 m,岩石整体呈灰黑色,块状构造,中粗粒花岗结构(图2b),矿物组成以长石、角闪石、石英为主,粒度在0.5~2 mm之间,副矿物有锆石、磷灰石等(图2c、图2d)。
2. 分析方法
本次锆石U-Pb、全岩主微量地球化学与锆石Lu-Hf同位素测试分析工作均在武汉上谱分析科技有限责任公司完成。锆石U-Pb同位素定年和微量元素含量利用LA-ICP-MS同时分析完成,GeolasPro激光剥蚀系统由COMPexPro 102 ArF 193 nm准分子激光器和MicroLas光学系统组成,ICP-MS型号为Agilent 7700e,详细的仪器参数和分析流程见Zong等(2017)和李艳广等(2023)。分析数据的离线处理(包括对样品和空白信号的选择、仪器灵敏度漂移校正、元素含量及U-Pb同位素比值和年龄计算)采用软件ICPMSDataCal(Liu et al., 2008, 2010)完成。锆石样品的U-Pb年龄谐和图绘制和年龄加权平均计算采用Isoplot/Ex_ver3(Ludwig, 2003)完成。全岩主量元素含量利用日本理学PrimusⅡ X射线荧光光谱仪(XRF)分析完成,微量元素含量利用Agilent 7700e ICP-MS分析完成。原位微区锆石Lu-Hf同位素比值测试利用激光剥蚀多接收杯等离子体质谱(LA-MC-ICP-MS)完成。激光剥蚀系统为Geolas HD(Coherent,德国),MC-ICP-MS为Neptune Plus(Thermo Fisher Scientific,德国)。
3. 分析结果
3.1 锆石U-Pb定年与Lu-Hf同位素
花岗闪长岩锆石整体呈无色透明的长柱状,晶形完好,粒径为200~300 μm,长宽比为2∶1~3∶1(图3)。本次共对20颗锆石进行测试分析工作(表1),20颗锆石测点206Pb/238U年龄均集中在162~154 Ma之间。在谐和图上(图3),所有测点都落在谐和线上或附近区域,获得锆石206Pb/238U年龄加权平均值为(158.4±1.8)Ma(MSWD=0.15),这与前人在卡易错花岗岩体中获得的168~160 Ma的年龄信息基本一致,代表了花岗闪长岩的形成时代。
表 1 卡易错花岗闪长岩LA-ICP-MS锆石U-Pb定年分析结果Table 1. LA-ICP-MS U-Pb dating results for zircons of Kayico granodiorites点号 同位素比值(1σ) 年龄比值(Ma) 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ 18T12-01 0.04954 0.00219 0.17017 0.00781 0.02491 0.00066 173 59 160 7 159 4 18T12-02 0.04929 0.00266 0.16824 0.00927 0.02475 0.00067 162 78 158 8 158 4 18T12-03 0.04965 0.00191 0.16944 0.00690 0.02475 0.00064 179 50 159 6 158 4 18T12-04 0.04989 0.00233 0.16974 0.00824 0.02467 0.00064 190 66 159 7 157 4 18T12-05 0.04939 0.00438 0.17064 0.01519 0.02505 0.00071 166 147 160 13 159 4 18T12-06 0.05092 0.00237 0.16985 0.00810 0.02419 0.00066 237 61 159 7 154 4 18T12-07 0.04885 0.00211 0.16623 0.00740 0.02467 0.00067 141 56 156 6 157 4 18T12-08 0.04955 0.00218 0.17037 0.00777 0.02493 0.00066 174 59 160 7 159 4 18T12-09 0.04888 0.00299 0.16655 0.01042 0.02471 0.00064 142 95 156 9 157 4 18T12-10 0.05012 0.00238 0.17289 0.00852 0.02501 0.00065 201 67 162 7 159 4 18T12-11 0.04908 0.00453 0.16867 0.01561 0.02492 0.00071 152 154 158 14 159 4 18T12-12 0.04889 0.00190 0.16671 0.00681 0.02472 0.00065 143 50 157 6 157 4 18T12-13 0.04940 0.00280 0.17026 0.00980 0.02499 0.00069 167 83 160 9 159 4 18T12-14 0.04970 0.00173 0.16964 0.00637 0.02475 0.00064 181 43 159 6 158 4 18T12-15 0.04905 0.00219 0.16888 0.00775 0.02496 0.00068 150 59 158 7 159 4 18T12-16 0.04950 0.00233 0.17051 0.00831 0.02498 0.00066 172 66 160 7 159 4 18T12-17 0.05017 0.00176 0.17246 0.00651 0.02492 0.00064 203 44 162 6 159 4 18T12-18 0.04892 0.00463 0.16803 0.01594 0.02490 0.00071 144 159 158 14 159 4 18T12-19 0.05000 0.00226 0.17212 0.00808 0.02496 0.00066 195 62 161 7 159 4 18T12-20 0.04862 0.00207 0.17018 0.00751 0.02538 0.00068 130 56 160 7 162 4 此外,对8颗获得谐和年龄的锆石进行原位Lu-Hf同位素测试(表2),8颗锆石测点的176Yb/177Hf在
0.012865 ~0.037412 之间,176Lu/177Hf在0.000427 ~0.001145 之间,表明所测锆石放射成因Hf的积累很少(吴福元等, 2007),测定的176Hf/177Hf(0.282602 ~0.282669 )值可以用来代替锆石的初始176Hf/177Hf值。8个测点Hf同位素地壳模式年龄TDMC为1090 ~1222 Ma,对应的εHf(t)值变化范围在−2.66~−0.27之间。表 2 卡易错花岗闪长岩锆石Lu-Hf同位素组成Table 2. Lu-Hf isotopes of zircons from the Kayico granodiorites.点号 年龄 (Ma) 176Hf/177Hf 1σ 176Lu/177Hf 1σ 176Yb/177Hf 1σ εHf(0) 1σ εHf(t) 1σ TDM1 TDMC fLu/Hf 18T12-01 159 0.282608 0.000008 0.000562 0.000003 0.017391 0.000117 −5.81 0.59 −2.38 0.60 901 1207 −0.98 18T12-02 158 0.282602 0.000009 0.000996 0.000005 0.031211 0.000271 −6.03 0.61 −2.66 0.62 921 1222 −0.97 18T12-03 158 0.282609 0.000010 0.000842 0.000026 0.026596 0.000831 −5.77 0.61 −2.39 0.62 907 1207 −0.97 18T12-04 154 0.282618 0.000010 0.000867 0.000013 0.027469 0.000376 −5.46 0.62 −2.17 0.63 895 1191 −0.97 18T12-05 159 0.282641 0.000009 0.000427 0.000002 0.012865 0.000067 −4.65 0.61 −1.20 0.62 853 1142 −0.99 18T12-06 157 0.282643 0.000009 0.000608 0.000005 0.019402 0.000131 −4.57 0.60 −1.18 0.61 854 1139 −0.98 18T12-07 159 0.282631 0.000008 0.000532 0.000001 0.016431 0.000077 −4.98 0.59 −1.55 0.60 868 1161 −0.98 18T12-08 159 0.282669 0.000009 0.001145 0.000043 0.037412 0.001346 −3.64 0.60 −0.27 0.61 829 1090 −0.97 3.2 地球化学
本次共采集4件花岗闪长岩样品进行全岩主微量元素地球化学分析工作,分析结果见表3。4件样品的地球化学组成相对均一,其SiO2含量为62.6%~65.2%,Al2O3含量为15.9%~16.6%,TiO2含量为0.68%~0.81%,TFe2O3含量为4.53%~5.37%,MgO含量为2.06%~2.34%,全碱(Na2O+K2O)含量为5.40%~5.56%,Na2O/K2O值为0.94~1.10,Mg#为50~52。在岩石类型判别图解中(图4a),样品均在花岗闪长岩区域;在K2O-SiO2图解中(图4b),样品显示中钾–高钾钙碱性的特征;在A/NK-A/CNK图解中(图3c),样品整体显示弱过铝质的特征(A/CNK=1.02~1.05)。以上主量元素地球化学组成表明样品整体显示弱过铝质中钾-高钾钙碱性花岗闪长岩的特征。
表 3 卡易错花岗闪长岩全岩主量(%)和微量(10−6)元素分析结果Table 3. Whole-rock major (%) and trace (10−6) element contents of Kayico granodiorites元素 T12h1 T12h2 T12h3 T12h4 元素 T12h1 T12h2 T12h3 T12h4 SiO2 63.6 65.2 64.5 62.6 Zr 248 230 244 245 TiO2 0.78 0.68 0.71 0.81 Nb 13.8 13.1 13.7 14.1 Al2O3 16.1 15.9 16.2 16.6 Sn 3.58 5.26 4.55 4.30 TFe2O3 5.37 4.53 4.82 5.12 Cs 17.5 21.1 14.6 20.0 MnO 0.08 0.06 0.07 0.07 Ba 457 383 401 428 MgO 2.34 2.06 2.07 2.33 La 29.8 32.7 32.1 30.2 CaO 4.48 4.44 4.38 4.83 Ce 66.7 68.5 63.0 61.6 Na2O 2.70 2.74 2.83 2.74 Pr 6.97 7.45 7.02 6.90 K2O 2.86 2.78 2.57 2.77 Nd 26.37 28.1 27.3 25.4 P2O5 0.15 0.13 0.14 0.15 Sm 5.26 5.68 5.75 5.24 LOI 0.99 1.11 1.30 1.30 Eu 1.11 1.05 1.14 1.16 SUM 99.5 99.7 99.5 99.3 Gd 5.08 4.65 4.55 4.66 Li 56.7 49.2 63.6 54.6 Tb 0.83 0.83 0.78 0.74 Be 1.97 2.31 2.18 2.07 Dy 4.95 5.01 4.54 4.49 Sc 14.9 12.7 13.8 14.8 Ho 1.00 1.01 0.91 0.92 V 74.0 61.3 67.1 74.1 Er 2.83 2.87 2.72 2.60 Cr 40.0 32.8 37.6 37.7 Tm 0.45 0.43 0.40 0.41 Co 15.4 11.5 12.9 12.8 Yb 2.70 2.78 2.46 2.42 Ni 16.6 14.3 15.2 15.5 Lu 0.41 0.44 0.37 0.37 Cu 104 45.7 44.1 45.7 Hf 6.64 6.24 6.79 6.29 Zn 56.6 43.1 45.7 51.6 Ta 1.02 1.10 1.05 0.98 Ga 19.2 18.8 19.1 19.5 Tl 1.33 1.40 1.13 1.34 Rb 170 185 169 178 Pb 8.40 9.57 7.76 10.2 Sr 188 181 194 203 Th 14.4 16.9 15.5 12.4 Y 28.2 28.0 26.8 24.8 U 2.18 2.88 2.52 2.23 图 4 卡易错花岗岩TAS图解(Middlemost, 1994)(a)、K2O-SiO2图解(Le Maitre et al., 1989; Rickwood, 1989)(b)和A/NK-A/CNK图解(c)(Shand, 1943)Figure 4. (a) TAS classification diagram, (b) K2O vs. SiO2 diagram and (c) A/NK vs. A/CNK diagram of Kayico granitic rocks在球粒陨石标准化稀土元素配分曲线中,样品呈轻稀土元素富集、重稀土元素亏损的右倾模式([La/Yb]N=7.90~9.34),同时具有不同程度的Eu负异常(Eu/Eu*=0.62~0.72)(图5a)。在原始地幔标准化蛛网图中,样品具有明显Nb、Ta等高场强元素以及Ba、Sr、Eu等大离子亲石元素的亏损(图5b)。
图 5 岩石球粒陨石标准化稀土元素模式图(a)和原始地幔标准化微量元素蛛网图(b)(标准化值引自Sun 等1989)Figure 5. (a) Chondrite-normalized rare earth element and (b) primitive-mantle–normalized multi-element patterns4. 讨论
4.1 中-晚侏罗世岩浆活动
近年来,国内外学者已经对青藏高原中部出露的岩浆岩开展了系统的研究工作,报道了大量的年代学和地球化学数据(Li et al., 2014; Liu et al., 2014; Wu et al., 2016; 刘海永等, 2022)。越来越多的研究表明在南羌塘地块南缘的卡易错、材玛、青草山、改则、荣玛、高保约一带存在一期大规模的中—晚侏罗世岩浆活动(约165~150 Ma),这些岩浆岩整体呈带状近平行于班–怒带出露,EW向延伸近上千千米,岩石类型整体以中酸性侵入岩为主,具有持续时间长、分布范围广的特征(图1b)。前人的研究在卡易错花岗岩体中获得了168~160 Ma的锆石U-Pb年龄信息(Liu et al., 2014; Li et al., 2014),本次锆石U-Pb定年工作在卡易错花岗闪长岩中获得了158 Ma的年龄,表明区内花岗岩形成于中—晚侏罗世之交,与南羌塘地块上大规模发育的中酸性侵入岩形成时代相近,应该是区域上同一期构造–岩浆活动的产物。
此外,Wu等(2018)对南羌塘地块上发育的中—晚侏罗世侵入岩进行了系统的地球化学对比研究,研究发现该期侵入岩整体显示复杂的地球化学特征,根据岩石的主、微量元素含量和同位素地球化学特征,可以划分为普通钙碱性I型花岗岩、高分异花岗岩、富Na埃达克岩与富K埃达克岩等不同的岩石类型,反应了区域上花岗质岩石复杂的岩浆源区与成岩过程。而根据现有地球化学资料,卡易错花岗岩可以划分为普通钙碱性I型花岗岩和高分异型花岗岩两类(Li et al., 2014; Liu et al., 2014),然而二者之间有何成因联系尚不明确。
4.2 构造背景
大量的岩浆岩研究资料表明青藏高原中部中生代岩浆作用整体沿班–怒带展布,主要发育在混杂带上及其两侧的南羌塘地块南缘和拉萨地块北缘,显示与与班–怒洋密切的时空联系,系统的研究工作已经初步建立中生代多期次岩浆作用与班–怒洋俯冲闭合过程之间的成因联系(Zhu et al., 2011, 2016; Kapp et al., 2019; Wu et al., 2019a, 2019b)。尽管对于班–怒洋的闭合时限一直存在争论,然而现有的争议均认为班–怒洋闭合与拉萨–羌塘地块陆陆碰撞应不早于白垩纪,而青藏高原中部侏罗纪构造演化主要受班–怒洋俯冲消减作用的影响(Liu et al., 2022)。此外,班–怒带上蛇绿混杂岩系统的年代学和地球化学的研究同样表明班–怒洋洋盆在中—晚侏罗世仍存有一定的规模(范建军等, 2019; 李志军等, 2019; 唐跃等, 2021)。
卡易错花岗闪长岩显著的Nb、Ta等元素亏损(图5),显示与俯冲成因的弧型岩浆岩相似的地球化学特征。近年来,不同学者对南羌塘地块上发育的中—晚侏罗世岩浆岩开展了大量的研究工作,陆续取得了众多的研究进展(Liu et al., 2014; Li et al., 2016; Wu et al., 2016)。其中,中酸性侵入岩整体显示陆缘弧的地球化学特征,而洋壳熔融成因的埃达克质花岗岩的识别则为深部俯冲洋壳的存在提供了最直接的岩石学证据(Li et al., 2016)。此外,区域上还陆续报道了中—晚侏罗世俯冲成因的钙碱性弧型安山岩与OIB型辉绿岩(李小波等, 2015; 董宇超等, 2016; Li et al., 2016),如此复杂多样的岩石组合反映了俯冲带上复杂的源区物质组成与循环过程。不仅如此,最近的研究提出班–怒洋的初始俯冲起始于晚三叠世末—早侏罗世(Qian et al., 2020; Liu et al., 2022),进一步表明班–怒洋中—晚侏罗世应处于洋壳俯冲背景。综上所述,南羌塘地块南缘出露的中—晚侏罗世岩浆岩应该形成于洋壳俯冲背景,是班-怒洋北向俯冲至南羌塘地块之下引发的弧型岩浆活动。
4.3 岩石类型与成因
花岗岩的类型划分与岩石成因长期以来一直以来是众多地质学家关注的热点研究问题,其中Chappell等(1974, 1992)根据花岗岩的岩浆源区物质组成和成岩构造环境的差异将花岗岩划分为I、S、M、A型4类,该分类方式已经被广泛运用于花岗岩成因与演化的研究工作(王亮等, 2022; 孙巍等, 2022)。Li等(2014)和Liu等(2014)对区内花岗岩岩石开展了年代学和地球化学的研究工作,识别了普通钙碱性I型和高分异型两类花岗岩。笔者在新获得的卡易错花岗闪长岩研究资料的基础上,进一步收集整理了前人已报道的卡易错花岗岩体的数据资料,以此准确约束卡易错地区花岗质岩石的岩石类型与成因。
卡易错花岗岩整体具有低的Zr+Ce+Nb+Y含量,然而根据其(Na2O+K2O)/CaO和FeOt/MgO值的不同,区内岩石可以划分为高分异与未分异两组(图6a、图6b )。不同于前人报道的高分异型花岗岩,本次采集的花岗闪长岩样品显示低的(Na2O+K2O)/CaO和FeOt/MgO值,具有未分异花岗岩的特征。在P2O5-SiO2和Th-Rb图解中,花岗闪长岩样品均显示出I型花岗岩的演化趋势(图6c、图6d)。结合花岗闪长岩弱过铝质的特征(图4c),卡易错花岗闪长岩应该属于普通钙碱性I型花岗岩。I型花岗岩一般认为起源于变火成岩下地壳部分熔融或者幔源物质对变沉积岩下地壳的改造(Petford et al., 1996; Chappell et al., 2001; Li et al., 2007),研究区内乃至整个南羌塘地块南缘均未发现大规模幔源岩浆活动成因的基性岩,结合花岗闪长岩相对均一的锆石原位Hf同位素组成(εHf(t)=−2.66~−0.27),卡易错花岗闪长岩难以解释为幔源物质与变沉积岩下地壳熔体混合的产物。同时,花岗闪长岩具有高的CaO/Na2O以及低的Al2O3/TiO2和Rb/Ba、Rb/Sr值,进一步指示着其起源于玄武质火成岩下地壳的部分熔融(图7a、 图7b)。此外,花岗闪长岩中不同程度的Eu、Sr、Ba等元素的负异常一般认为是成岩过程中存在着长石类矿物的结晶分异,而Nb、Ta等元素的亏损则和金红石/榍石的结晶分离相关。综上所述,卡易错花岗闪长岩应该是南羌塘地块之下古老的变火成岩下地壳熔体经历一定结晶分异作用的产物。
图 6 卡易错花岗岩(Na2O/K2O)/CaO-Zr+Ce+Nb+Y图解(a)、FeOt/MgO-Zr+Ce+Nb+Y图解(b)(Whalen et al., 1987)、P2O5-SiO2图解(c)和Th-Rb图解(d)(Li et al., 2007)Figure 6. Geochemical classification diagrams of Kayico granitic rocks: (a)(Na2O/K2O)/CaO vs. Zr+Ce+Nb+Y diagram, (b) FeOt/MgO vs. Zr+Ce+Nb+Y diagram, (c) P2O5 vs. SiO2diagram, (d) Th vs. Rb diagram of Kayico granitic rocks图 7 卡易错花岗岩CaO/Na2O-Al2O3/TiO2图解(a)、Rb/Ba-Rb/Sr图解(b)(Sylvester, 1998)、 Rb/Sr-Sr图解(c)、Ba-Sr图解(d)(Rollinson, 1993)Amp.闪石;Bi.黑云母;Kfs.钾长石;Pl.斜长石Figure 7. (a) CaO/Na2O vs. Al2O3/TiO2 diagram, (b) Rb/Ba vs. Rb/Sr diagram, (c) Rb/Sr vs. Sr diagram, (d) Ba vs. Sr diagram of Kayico granitic rocks卡易错高分异型花岗岩具有与钙碱性I型花岗岩形成时代一致,在空间上密切共生,并相似的锆石Hf同位素特征,表明二者具有相似的岩浆源区物质组成(Li et al., 2014; Liu et al., 2014)。然而,高分异型花岗岩显示强烈的亏损Eu、Sr、Ba等元素(图5),指示着岩浆在侵位过程中经历了强烈的结晶分异作用。在Rb/Sr-Sr和Ba-Sr图解中,卡易错两类花岗岩之间显示出明显的长石类矿物分离结晶趋势(图7c、图7d),进一步表明卡易错不同类型花岗岩地球化学的差异是后期岩浆侵位过程中经历不同演化过程的产物。近年来,晶粥体模型(MUSH)被广泛应用于解释同期共生花岗闪长岩与高分异型花岗岩之间的成因联系(Bachmann et al., 2004; Hildreth, 2004),该模型提出花岗质岩浆在浅层岩浆房中发生矿物结晶时,形成一种晶体与液体共存的晶粥体,其外围的物质结晶形成富含斑晶的花岗质岩石,而中心的残余岩浆则形成高分异的高硅花岗岩(Wu et al., 2017)。晶粥体模型无疑为卡易错地区空间上相伴生、时代上相一致的普通钙碱性I型花岗岩和高分异型花岗岩提供了合理的成因解释。因此,研究认为,在中—晚侏罗世班–怒洋持续北向俯冲过程中,底侵的幔源玄武质岩浆诱发南羌塘地块之下古老的变火成岩下地壳物质发生重熔,形成的熔体上升侵位、并在浅层岩浆房内发生显著低压结晶分异作用,其外围的晶粥体与内部的熔体分别冷凝形成了卡易错地区普通钙碱性I型和高分异型两类花岗质岩石(图8)。
5. 结论
(1)锆石U-Pb年龄表明,卡易错花岗闪长岩形成于158 Ma,与前人在卡易错岩体中获得的168~160 Ma的年龄相一致,是南羌塘地块南缘中—晚侏罗世构造-岩浆活动的产物。
(2)卡易错花岗闪长岩具有钙碱性I型花岗岩的地球化学特征,以及相对富集的锆石Hf同位素组成,是班-怒洋中-晚侏罗世北向俯冲背景下南羌塘地块古老的变火成岩下地壳熔融的产物。
(3)结合现有研究资料,晶粥体模式为卡易错地区钙碱性I型与高分异型两类花岗岩提供了合理的成因解释,二者是壳源熔体在浅层岩浆房内经历结晶分异后不同端元冷凝的产物。
致谢:野外工作得到西藏自治区地质调查院刘海永博士和吉林大学罗安波博士等人的帮助,审稿专家对稿件提出的宝贵意见对论文质量提高至关重要,在此一并致以衷心的感谢。
-
图 2 鄂东南地区岩浆岩和矿床分布简图(据Li et al., 2014a修改)
Figure 2. Distribution of igneous rocks and mineral deposits in southeastern Hubei Province
图 8 鄂东南矿集区继承锆石Hf同位素组成及其与江南造山带西段基底碎屑锆石和崆岭杂岩锆石Hf同位素对比
图中黑色数据点均为鄂东南矿集区继承锆石数据,数据来源见表3;江南造山带西段基底碎屑锆石数据引自Wang et al.,(2010);崆岭杂岩数据范围据邱啸风等 (2014)、Li等(2014b)、Guo等(2015);鄂东南地区晚中生代侵入岩范围据Xie等(2011a)
Figure 8. Inheritance zircon Hf isotopic composition in the southeastern Hubei mineral district and its comparison with the Hf isotopic compositions of detrital zircons from the western segment of the Jiangnan Orogen and zircons from the Kongling Complex
表 1 灵乡闪长玢岩锆石年龄数据
Table 1 Zircon U-Pb age data of Lingxiang dioritic porphyrite
分析点 Th
(10−6)U
(10−6)Th/U 同位素比值 年龄(Ma) 误差
(%)207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ D020-3-1-01 47 32 1.5 0.1105 0.0052 5.1151 0.2333 0.3364 0.0070 1807 86.4 1839 38.8 1869 33.7 103 D020-3-1-02 56 44 1.3 0.1017 0.0055 4.2227 0.2309 0.2991 0.0059 1655 101.1 1678 44.9 1687 29.3 102 D020-3-1-03 1014 599 1.7 0.0949 0.0032 3.0391 0.0968 0.2297 0.0026 1528 62.7 1417 24.3 1333 13.7 87 D020-3-1-04 250 287 0.9 0.1590 0.0048 9.2537 0.2654 0.4182 0.0048 2445 50.8 2363 26.3 2252 21.9 92 D020-3-1-06 200 220 0.9 0.0545 0.0062 0.1602 0.0152 0.0219 0.0007 391 252.7 151 13.3 140 4.6 93 D020-3-1-07 230 184 1.3 0.1080 0.0043 4.2916 0.1689 0.2860 0.0042 1765 72.2 1692 32.4 1621 21.0 92 D020-3-1-09 554 881 0.6 0.0544 0.0024 0.3900 0.0277 0.0508 0.0026 387 98.1 334 20.2 319 15.8 96 D020-3-1-10 363 561 0.6 0.0476 0.0029 0.1460 0.0092 0.0220 0.0004 79.7 140.7 138 8.1 140 2.6 102 D020-3-1-11 199 193 1.0 0.1099 0.0033 5.0993 0.1651 0.3330 0.0052 1798 54.5 1836 27.5 1853 25.2 103 D020-3-1-12 515 737 0.7 0.0917 0.0028 3.1650 0.0941 0.2478 0.0030 1461 52.9 1449 23.0 1427 15.4 98 D020-3-1-13 293 562 0.5 0.0588 0.0025 0.6222 0.0261 0.0760 0.0010 567 94.4 491 16.3 472 5.9 96 D020-3-1-14 241 205 1.2 0.0510 0.0052 0.1580 0.0164 0.0222 0.0005 243 218.5 149 14.4 142 3.0 95 D020-3-1-15 255 743 0.3 0.0545 0.0027 0.2570 0.0123 0.0342 0.0005 391 113.0 232 9.9 217 3.2 93 D020-3-1-16 313 401 0.8 0.0552 0.0022 0.5839 0.0236 0.0764 0.0009 420 92.6 467 15.1 474 5.5 102 D020-3-1-17 2820 1631 1.7 0.0508 0.0052 0.1585 0.0188 0.0219 0.0009 232 218.5 149 16.5 140 5.9 93 D020-3-1-18 135 64 2.1 0.0564 0.0070 0.5589 0.0592 0.0738 0.0018 478 275.9 451 38.6 459 10.9 102 D020-3-1-19 437 757 0.6 0.0571 0.0028 0.3134 0.0144 0.0401 0.0007 494 107.4 277 11.1 254 4.1 92 D020-3-1-20 384 565 0.7 0.0716 0.0028 1.4407 0.0595 0.1461 0.0026 976 79.6 906 24.8 879 14.4 97 D020-3-1-21 113 96 1.2 0.1690 0.0057 10.7709 0.3818 0.4625 0.0067 2550 57.6 2504 33.0 2451 29.6 96 D020-3-1-22 139 204 0.7 0.0571 0.0037 0.3524 0.0223 0.0452 0.0007 494 142.6 307 16.8 285 4.4 93 表 2 灵乡闪长玢岩锆石Hf同位素数据
Table 2 Zircon Hf isotope data of Lingxiang dioritic porphyrite
样品编号 176Lu/177Hf 1σ 176Hf/177Hf 1σ 176Yb/177Hf 1σ 年龄(Ma) (176Hf/177Hf)i εHf(t) TDM (Ma) T2DM (Ma) D20-3-1 - 1 0.000570 0.000005 0.281424 0.000009 0.021425 0.000240 1807 0.281404 −8.1 2526 2964 D20-3-1 - 2 0.000663 0.000013 0.281489 0.000010 0.025059 0.000457 1655 0.281468 −9.3 2443 2921 D20-3-1 - 3 0.001057 0.000021 0.282144 0.000011 0.038954 0.000827 1528 0.282113 10.7 1564 1585 D20-3-1 - 4 0.000600 0.000006 0.281100 0.000008 0.022012 0.000191 2445 0.281072 −5.1 2963 3280 D20-3-1 - 6 0.002287 0.000044 0.282495 0.000036 0.071227 0.001076 140 0.282489 −7.4 1108 1627 D20-3-1 - 7 0.001532 0.000027 0.281691 0.000023 0.050118 0.000749 1765 0.281640 −0.7 2218 2477 D20-3-1 - 9 0.001994 0.000048 0.282431 0.000026 0.064281 0.001985 319 0.282419 −5.8 1191 1670 D20-3-1 - 10 0.001281 0.000031 0.282579 0.000013 0.050481 0.000824 140 0.282576 −4.3 959 1433 D20-3-1 - 11 0.000457 0.000015 0.281549 0.000013 0.016213 0.000459 1798 0.281534 −3.7 2348 2687 D20-3-1 - 12 0.001862 0.000045 0.282169 0.000018 0.062988 0.001202 1461 0.282118 9.3 1561 1617 D20-3-1 - 13 0.001463 0.000028 0.282251 0.000010 0.049887 0.000612 472 0.282238 −8.8 1429 1975 D20-3-1 - 14 0.002842 0.000031 0.282530 0.000031 0.092366 0.000907 142 0.282522 −6.1 1074 1552 D20-3-1 - 15 0.001126 0.000022 0.282463 0.000009 0.037917 0.000721 217 0.282459 −6.7 1119 1646 D20-3-1 - 16 0.002427 0.000064 0.282664 0.000013 0.075969 0.001666 474 0.282642 5.5 866 1075 D20-3-1 - 17 0.000989 0.000032 0.282407 0.000015 0.032420 0.000913 140 0.282404 −10.4 1193 1815 D20-3-1 - 18 0.001332 0.000025 0.282729 0.000016 0.055075 0.000864 459 0.282717 7.8 748 916 D20-3-1 - 19 0.002403 0.000101 0.282322 0.000015 0.086403 0.003255 254 0.282310 −11.2 1364 1952 D20-3-1 - 20 0.001155 0.000023 0.282295 0.000016 0.040620 0.000626 879 0.282276 1.7 1356 1635 D20-3-1 - 21 0.000745 0.000029 0.281511 0.000020 0.028769 0.000946 2550 0.281475 11.7 2418 2338 D20-3-1 - 22 0.001094 0.000019 0.282632 0.000012 0.042042 0.000667 285 0.282626 0.7 880 1230 注:206Pb/238U 年龄< 1000 Ma时,Con% = (206Pb/238U年龄/207Pb/235U年龄)×100%;206Pb/238U 年龄>1000 Ma时,Con% = (206Pb/238U年龄/207Pb/206Pb年龄)×100%。表 3 鄂东南矿集区内继承锆石U-Pb年龄及Hf同位素数据汇总表
Table 3 Inherited zircon age and Hf isotope data of intrusions in the Southeastern Hubei Province
岩体 点号 Th(10−6) U(10−6) Th/U 年龄(Ma) εHf(t) TDM(Ma) T2DM(Ma) 数据来源 鄂城 CC375–16–5 – – – 1569 −0.5 2040 2311 Xie et al., 2011a 铁山 TS3–7 399 596 0.7 1871 −0.7 2299 2558 D20-3-1 - 1 47 32 1.5 1807 −8.1 2526 2964 − D20-3-1 - 2 56 44 1.3 1655 −9.3 2443 2921 − D20-3-1 - 3 1014 599 1.7 1528 10.7 1564 1585 − D20-3-1 - 4 250 287 0.9 2445 −5.1 2963 3280 − D20-3-1 - 7 230 184 1.3 1765 −0.7 2218 2477 − D20-3-1 - 9 554 881 0.6 319 −5.8 1191 1670 文中 灵乡 D20-3-1 - 11 199 193 1.0 1798 −3.7 2348 2687 − D20-3-1 - 12 515 737 0.7 1461 9.3 1561 1617 − D20-3-1 - 13 293 562 0.5 472 −8.8 1429 1975 − D20-3-1 - 15 255 743 0.3 217 −6.7 1119 1646 − D20-3-1 - 16 313 401 0.8 474 5.5 866 1075 − D20-3-1 - 18 135 64 2.1 459 7.8 748 916 − D20-3-1 - 19 437 757 0.6 254 −11.2 1364 1952 − D20-3-1 - 20 384 565 0.7 879 1.7 1356 1635 − D20-3-1 - 21 113 96 1.2 2550 11.7 2418 2338 − D20-3-1 - 22 139 204 0.7 285 0.7 880 1230 ZK02810-6-06c 133 170 0.8 1207 −8.9 2063 2549 − ZK02810-6-08c 53 133 0.4 2220 −2.6 2670 2953 − ZK02810-6-10c 67 139 0.5 2505 8.9 2483 2470 − ZK02810-6-11c 96 164 0.6 2046 3.6 2292 2435 铜绿山 ZK02810-6-15c 79 76 1.0 2293 2.6 2541 2688 黄圭成等,2013 ZK02810-6-17c 67 97 0.7 2613 8.9 2578 2556 − ZK02810-6-21c 158 466 0.3 1979 1.2 2318 2526 − ZK02810-6-18c 103 95 1.1 2895 6.2 2927 2946 − Dy254-1-13c 49 24 2.0 799 − − − − Dy254-1-21c 69 109 0.6 1127 −15.0 2205 2861 − TLS801-103-3 31 22 1.4 1820 −7.0 2494 2909 − TLS801-103-4 172 286 0.6 751 −6.0 1543 2015 − TLS801-103-6 113 194 0.6 2613 −1.4 2974 3188 − TLS801-103-8 114 92 1.2 2061 − − − − TLS801-103-9 41 61 0.7 1732 −7.1 2421 2846 − TLS801-103-14 202 155 1.3 299 −12.1 1400 2043 − TLS801-103-15 147 139 1.1 850 − − − − TLS801-103-16 187 344 0.5 1862 −0.2 2276 2521 − TLS801-103-21 160 180 0.9 2457 5.8 2562 2627 − TLS801-103-22 316 426 0.7 1132 − − − − TLS801-103-30 462 435 1.1 320 − − − − TLS801-103-32 491 382 1.3 263 − − − − TLS801-103-34 313 168 1.9 830 − − − − 铜绿山煌斑岩 TLS803-159-1 185 85 2.2 837 −20.6 2203 2982 − TLS803-159-2 108 136 0.8 323 11.5 480 572 Zhang et al., 2021a TLS803-159-3 30 61 0.5 1632 −9.0 2411 2885 − TLS803-159-14 251 397 0.6 836 − − − − TLS803-159-15 545 563 1.0 997 − − − − TLS803-159-16 140 201 0.7 2498 − − − − TLS803-159-17 335 352 0.9 423 − − − − TLS803-159-18 143 248 0.6 2345 − − − − TLS803-159-19 50 149 0.3 2567 − − − − TLS803-159-20 264 424 0.6 427 − − − − TLS803-159-21 71 110 0.6 784 − − − − TLS803-159-22 216 291 0.7 880 − − − − TLS803-159-23 121 115 1.1 2147 − − − − TLS803-159-24 332 388 0.9 835 − − − − TLS803-159-25 195 148 1.3 421 − − − − TLS803-159-26 89 411 0.2 1950 − − − − TLS803-159-27 373 641 0.6 437 − − − − TLS803-159-28 436 612 0.7 444 − − − − TLS803-159-29 30 44 0.7 2469 − − − − 阳新 YX2–7 377 170 2.2 1117 −4.9 1812 2229 Xie et al., 2011a Dy116-06 872 1008 0.9 614 −7.6 1490 2006 丁丽雪等,2016 Dy116-15 184 253 0.7 422 Dy311-01 51 303 0.2 2258 −3.6 2738 3040 − Dy311-03 27 226 0.1 1713 −7.0 2408 2823 − Dy311-06 53 70 0.8 1158 −0.7 1685 2002 − 姜桥 Dy311-10 11 27 0.4 2117 −14.4 3019 3588 − Dy311-13 120 143 0.8 1111 − − − 丁丽雪等,2013 Dy311-15 101 114 0.9 1127 − − − − Dy311-18 326 315 1.0 1124 − − − − Dy311-19 68 122 0.6 1182 − − − − Dy311-21 58 149 0.4 2032 − − − − 殷租* 08YZ38.1@6 227 117 1.9 2424 − − − Li et al., 2010 Dy314-13inh 77 107 0.7 1846 − − − − Dy314-15 96 281 0.3 313 − − − − Dy314-20 117 275 0.4 306 − − − − Dy314-21inh 56 27 2.0 1798 −23.2 3100 3869 − 铜鼓山 Dy314-22inh 161 126 1.3 1809 −23.2 3103 3881 夏金龙等,2013a Dy314-23inh 282 189 1.5 1884 −23.0 3173 3924 − Dy314-24inh 222 127 1.8 1888 − − − − Dy314-25inh 50 61 0.8 1728 − − − − Dy314-26inh 51 50 1.0 1574 − − − − DY145-1inh 19 46 0.4 2959 3.1 3101 3188 − DY145-2inh 98 89 1.1 1785 −14.6 2769 3344 − DY145-5inh 72 83 0.9 1803 − − − − DY145-8inh 92 60 1.5 1746 −18.1 2857 3526 − 古家山 DY145-11inh 324 526 0.6 2499 − − − 夏金龙等,2013b DY145-12inh 107 109 1.0 1847 −1.0 2292 2558 − DY145-13inh 77 107 0.7 2342 − − − − DY145-19inh 102 165 0.6 2036 1.1 2377 2583 − DY145-20inh 117 275 0.4 1929 − − − − XNS1-6 180 215 0.8 2358 − − − − 阮家湾 XNS1-7 40 136 0.3 2379 − − − 颜代蓉等,2012 XNS1-16 168 374 0.4 2337 − − − − XNS17-15 109 657 0.2 1816 − − − − 注:εHf(t)和模式年龄值均按照本文提供的参数重新计算。 -
蔡恒安, 徐江嬿, 陈松林, 等 . 鄂东南矿集区深部找矿进展及下步找矿思路[J]. 资源环境与工程,2020 ,34 (4 ):501 −505+511 .CAI Heng'an, XU Jiangyan, CHEN Songlin, et al . Deep Prospecting Progress and Next Prospecting Thoughts of Southeast Hubei Mining Area[J]. Resources Environment and Engineering,2020 ,34 (4 ):501 −505+511 .曹洛华, 葛宗侠 . 鄂东深部地质初步探讨[J]. 湖北地质,1987 ,1 (1 ):47 −59 .CAO Luohua, GE Zongxia . A Preliminary Approach to the Deep-Seated Geology of Eastern Hubei[J]. Geology of Hubei,1987 ,1 (1 ):47 −59 .常印佛, 董树文, 黄德志 . 论中-下扬子“一盖多底”格局与演化[J]. 火山地质与矿产,1996 ,17 (1-2 ):1 −15 .CHANG Yinfo, DONG Shuwen, HUANG Dezhi . On Tectonics of ‘Poly-Basement with One Cover’ in Middle-Lower Yangtze Carton China[J]. Volcanology and Mineral Resources,1996 ,17 (1-2 ):1 −15 .丁丽雪, 黄圭成, 夏金龙 . 鄂东南地区阳新复式岩体成因: LA-ICP-MS锆石U-Pb年龄及Hf同位素证据[J]. 高校地质学报,2016 ,22 (3 ):443 −458 .DING Lixue, HUANG Guicheng, XIA Jinlong . Petrogenesis of the Yangxin Complex in Southeast Hubei Province: Constraints from LA-ICP-MS U-Pb Ages and Hf Isotopes of Zircon[J]. Geological Journal of China Universities,2016 ,22 (3 ):443 −458 .丁丽雪, 黄圭成, 夏金龙 . 鄂东南地区殷祖岩体的成因及其地质意义: 年代学、地球化学和Sr-Nd-Hf同位素证据[J]. 地质学报,2017 ,91 (2 ):362 −383 . doi: 10.3969/j.issn.0001-5717.2017.02.005DING Lixue, HUANG Guicheng, XIA Jinlong . Petrogrnrsis and Implications of the Yinzu Pluton in Southeast Hubei Province: Evidence from Geochronology, Geochemistry, and Sr-Nd-Hf Isotopes[J]. Acta Geologica Sinica,2017 ,91 (2 ):362 −383 . doi: 10.3969/j.issn.0001-5717.2017.02.005丁丽雪, 黄圭成, 夏金龙, 等 . 鄂东南地区姜桥花岗闪长岩锆石U-Pb年龄、Hf同位素特征及其地质意义[J]. 岩石矿物学杂志,2013 ,32 (3 ):275 −290 .DING Lixue, HUANG Guicheng, XIA Jinlong, et al . U-Pb Ages and Hf Isotope Characteristics of Zircon from Jiangqiao Granodiorite in Southeastern Hubei Province and Their Geological Implications[J]. Acta Petrologica et Mineralogica,2013 ,32 (3 ):275 −290 .董树文, 马立成, 刘刚, 等 . 论长江中下游成矿动力学[J]. 地质学报,2011 ,85 (5 ):612 −625 .DONG Shuwen, MA Licheng, LIU Gang, et al . On Dynamics of the Metallogenic Belt of Middle-Lower Reaches of Yangtze River, Eastern China[J]. Acta Geologica Sinica,2011 ,85 (5 ):612 −625 .高林志, 陈建书, 戴传固, 等 . 黔东地区梵净山群与下江群凝灰岩SHRIMP锆石U-Pb年龄[J]. 地质通报,2014 ,33 (7 ):949 −959 . doi: 10.3969/j.issn.1671-2552.2014.07.002GAO Linzhi, CHEN Jianshu, DAI Chuan’gu, et al . Shrimp Zircon U-Pb Dating of Tuff in Fanjingshan Group and Xiajiang Group from Guizhou and Hunan Provinces and its Stratigraphic implications[J]. Geological Bulletin of China,2014 ,33 (7 ):949 −959 . doi: 10.3969/j.issn.1671-2552.2014.07.002黄圭成, 夏金龙, 丁丽雪, 等 . 鄂东南地区铜绿山岩体的侵入期次和物源: 锆石U-Pb年龄和Hf同位素证据[J]. 中国地质,2013 ,40 (5 ):1392 −1408 .HUANG Guicheng, XIA Jinlong, DING Lixue, et al . Stage Division and Origin of Tonglushan Pluton in Southeast Hubei Province: Evidence from Zircon U-Pb Ages and Hf Isotopes[J]. Geology in China,2013 ,40 (5 ):1392 −1408 .梁学堂, 李义, 徐元璋, 等 . 鄂西地区基底构造特征新认识——基于重磁场特征的判别[J]. 工程地球物理学报,2020 ,17 (4 ):432 −440 . doi: 10.3969/j.issn.1672-7940.2020.04.007LIANG Xuetang, LI Yi, XU Yuanzhang, et al . New Perspectives on the Basement Tectonic Features in Weastern Hubei: Based on the Discrimination of Gravity and Magnetic Fields Characteristics[J]. Chinese Journal of Engineering Geophysics,2020 ,17 (4 ):432 −440 . doi: 10.3969/j.issn.1672-7940.2020.04.007李平, 朱涛, 吕鹏瑞, 等 . 西天山早寒武世夏特辉长岩: 南天山洋早期俯冲的岩浆记录[J]. 西北地质,2024 ,57 (3 ):44 −58 .LI Ping, ZHU Tao, LÜ Pengrui, et al . Early Cambrian Xiate Gabbro in Western Tianshan: Magmatic Records of Initial Subduction of the South Tianshan Ocean[J]. Northwestern Geology,2024 ,57 (3 ):44 −58 .邱啸风 . 扬子克拉通北部前泥盆纪地壳: 来自碎屑锆石U-Pb和Hf同位素证据[J]. 地质学报,2022 ,96 (11 ):1 −25 . doi: 10.1111/1755-6724.14903QIU Xiaofeng . Pre-Devonian Crustal Evolution of the Northern Yangtze Craton: Evidence from U-Pb Ages and Hf Isotopes of Detrital Zircons[J]. Acta Geologica Sinica,2022 ,96 (11 ):1 −25 . doi: 10.1111/1755-6724.14903邱啸风, 凌文黎, 柳小明 . 扬子陆核与神农架地块中元古代相互关系: 来自锆石U-Pb年代学和H同位素的约束[J]. 地质科技情报,2014 ,33 (2 ):1 −8 .QIU Xiaofeng, LING Wenli, LIU Xiaoming . Correlation between the Mesoproterozoic Yangtze Continental Nucleus and the Shennongjia Area: Constraints from Zircon Geochronological and Hf Isotope[J]. Bulletin of Geological Science and Technology,2014 ,33 (2 ):1 −8 .冉亚洲, 陈涛, 梁文天, 等. 西秦岭郎木寺组火山岩锆石U–Pb年龄及其构造意义[J]. 西北地质, 2024, 57(1): 110−121. RAN Yazhou, CHEN Tao, LIANG Wentian, et al. Zircon U–Pb Age of Volcanic Rocks from the Langmusi Formation in the Western Qinling Mountains and Its Tectonic Significance[J]. Northwestern Geology, 2024, 57(1): 110−121.
舒全安, 陈培良, 程建荣. 鄂东铁铜矿产地质[M]. 北京: 冶金工业出版社, 1992. 谭忠福, 林玉石, 汤吉方, 等 . 鄂东南地区铁铜矿床的构造控制规律及其隐伏矿床的预测问题[J]. 中国地质科学院院报 宜昌地质矿产研究所分刊,1980 ,1 (2 ):1 −22 .TAN Zhongfu, LIN Yushi, TANG Jifang, et al . The Control of Tectonic Systems on the Iron (Copper) Ore Deposits and the Prognosis of Concealed Ore Deposits in Southeastern Hubei, China[J]. Journal of the Chinese Academy of Geological Sciences, Yichang Institute of Geology and Mineral Resources,1980 ,1 (2 ):1 −22 .王敏, 戴传固, 王雪华, 等 . 贵州梵净山群沉积时代——来自原位锆石U-Pb测年证据[J]. 岩石矿物学杂志,2012 ,31 (6 ):843 −857 . doi: 10.3969/j.issn.1000-6524.2012.06.006WANG Min, DAI Chuangu, WANG Xuehua, et al . Sedimentation Age of the Fanjingshan Group in East Guizhou Province: Evidence from In-Situ Zircon LA-ICP-MS U-Pb Dating[J]. Acta Petrologica et Mineralogica,2012 ,31 (6 ):843 −857 . doi: 10.3969/j.issn.1000-6524.2012.06.006王强, 赵振华, 许继峰, 等 . 鄂东南铜山口、殷祖埃达克质(adakitic)侵入岩的地球化学特征对比: (拆沉)下地壳熔融与斑岩铜矿的成因[J]. 岩石学报,2004 ,20 (2 ):351 −360 . doi: 10.3321/j.issn:1000-0569.2004.02.015WANG Qiang, ZHAO Zhenhua, XU Jifeng, et al . The Geochemical Comparison between the Tongshankou and Yinzu Adakitic Intrusive Rocks in Southeastern Hubei: (Delaminated) Lower Crustal Melting and the Genesis of Porphyry Copper Deposit[J]. Acta Petrologica Sinica,2004 ,20 (2 ):351 −360 . doi: 10.3321/j.issn:1000-0569.2004.02.015吴福元, 李献华, 郑永飞, 等 . Lu-Hf同位素体系及其岩石学应用[J]. 岩石学报,2007 ,23 (2 ):185 −220 . doi: 10.3969/j.issn.1000-0569.2007.02.001WU Fuyuan, LI Xianhua, ZHENG Yongfei, et al . Lu-Hf Isotopic Systematics and Their Applications in Petrology[J]. Acta Petrologica Sinica,2007 ,23 (2 ):185 −220 . doi: 10.3969/j.issn.1000-0569.2007.02.001吴元保, 郑永飞 . 锆石成因矿物学研究及其对U-Pb年龄解释的制约[J]. 科学通报,2004 ,49 (16 ):1589 −1604 . doi: 10.3321/j.issn:0023-074X.2004.16.002WU Yuanbao, ZHENG Yongfei . Genetic Mineralogy of Zircon and Its Restriction on U-Pb Age Interpretation[J]. Chinese Science Bulletin,2004 ,49 (16 ):1589 −1604 . doi: 10.3321/j.issn:0023-074X.2004.16.002夏金龙, 黄圭成, 丁丽雪, 等 . 鄂东南地区存在古元古代-太古宙基底—来自铜鼓山岩体锆石U-Pb-Hf同位素的证据[J]. 地球学报,2013a ,34 (6 ):691 −701 .XIA Jinlong, HUANG Guicheng, DING Lixue, et al . Paleoproterozoic-Archean Basement Beneath Southeast Hubei Province: Evidence from U-Pb-Hf Isotopes in Zircons from the Tonggushan Pluton[J]. Acta Geoscientica Sinica,2013a ,34 (6 ):691 −701 .夏金龙, 黄圭成, 丁丽雪, 等 . 鄂东南地区古家山岩体锆石U-Pb年龄和Hf同位素组成: 对岩浆源区的指示[J]. 华南地质与矿产,2013b ,29 (2 ):116 −125 .XIA Jinlong, HUANG Guicheng, DING Lixue, et al . Zircon U-Pb Age and Hf Isotope of the Gujiashan Pluton, Southeast Hubei Province: Implications for the Magma Source[J]. South China Geology,2013b ,29 (2 ):116 −125 .谢桂青, 李瑞玲, 蒋国豪, 等 . 鄂东南地区晚中生代侵入岩的地球化学和成因及对岩石圈减薄时限的制约[J]. 岩石学报,2008 ,24 (8 ):1703 −1714 .XIE Guiqing, LI Ruiling, JIANG Guohao, et al . Geochemistry and Petrogenesis of Late Mesozoic Granitoids in Southeastern Hubei Province and Constrains on the Timing of Lithospheric Thinning, Middle-Lower Reaches of the Yangtze River, Eastern China[J]. Acta Petrologica Sinica,2008 ,24 (8 ):1703 −1714 .谢桂青, 朱乔乔, 李伟, 等. 湖北大冶式铁矿地质[M]. 北京:地质出版社, 2016. 谢桂青, 朱乔乔, 姚磊, 等 . 鄂东南地区晚中生代铜铁金多金属矿的区域成矿模型探讨[J]. 矿物岩石地球化学通报,2013 ,32 (4 ):418 −426 . doi: 10.3969/j.issn.1007-2802.2013.04.005X IE Gguiqing, ZHU Qiaoqiao, YAO Lei, et al . Discussion on Regional Metal Mineral Deposit Model of Late Mesozoic Cu-Fe-Au Polymetallic Deposits in the Southeast Hubei Province[J]. Bulletin of Mineralogy, Petrology and Geochemistry,2013 ,32 (4 ):418 −426 . doi: 10.3969/j.issn.1007-2802.2013.04.005颜代蓉, 邓晓东, 胡浩, 等 . 鄂东南地区阮家湾和犀牛山花岗闪长岩的时代、成因及成矿和找矿意义[J]. 岩石学报,2012 ,28 (10 ):3373 −3388 .YAN Dairong, DENG Xiaodong, HU Hao, et al . U-Pb Age and Petrogenesis of the Ruanjiawan Granodiorite Pluton and Xiniushan Granodiorite Porphyry, Southeast Hubei Province: Implications for Cu-Mo Mineralization[J]. Acta Petrologica Sinica,2012 ,28 (10 ):3373 −3388 .翟裕生, 姚书振, 林新多, 等. 长江中下游地区铁铜(金)成矿规律[M]. 北京: 地质出版社, 1992. 张少兵, 郑永飞 . 扬子陆核的生长和再造: 锆石U-Pb年龄和Hf同位素研究[J]. 岩石学报,2007 ,23 (2 ):393 −402 . doi: 10.3969/j.issn.1000-0569.2007.02.018ZHANG Shaobing, ZHENG Yongfei . Growth and Reworking of the Yangtze Continental Nucleus: Evidence from Zircon U-Pb Ages and Hf Isotopes[J]. Acta Petrologica Sinica,2007 ,23 (2 ):393 −402 . doi: 10.3969/j.issn.1000-0569.2007.02.018赵新福, 李建威, 马昌前 . 鄂东南铁铜矿集区铜山口铜(钼)矿床40Ar/39Ar年代学及对区域成矿作用的指示[J]. 地质学报,2006 ,80 (6 ):849 −862 .ZHAO Xinfu, LI Jianwei, MA Changqian . 40Ar/39Ar Geochronology of the Tongshankou Cu (Mo) Deposit in the Southeastern Hubei Fe-Cu Province: Implications for Regional Metallogeny[J]. Acta Geologica Sinica,2006 ,80 (6 ):849 −862 .周涛发, 范裕, 王世伟, 等 . 长江中下游成矿带成矿规律和成矿模式[J]. 岩石学报,2017 ,33 (11 ):3373 −3372 .ZHOU Taofa, FAN Yu, WANG Shiwei, et al . Metallogenic Regularity and Metallogenic Model of the Middle-Lower Yangtze River Valley Metallogenic Belt[J]. Acta Petrologica Sinica,2017 ,33 (11 ):3373 −3372 .Belousova E, Griffin W, O'Reilly S Y, et al . Igneous zircon: trace element composition as an indicator of source rock type[J]. Contributions to Mineralogy and Petrology,2002 ,143 (5 ):602 −622 .Bouvier A, Vervoort J D, Patchett, P J . The Lu–Hf and Sm–Nd isotopic composition of CHUR: Constraints from unequilibrated chondrites and implications for the bulk composition of terrestrial planets[J]. Earth and Planetary Science Letters,2008 ,273 (1-2 ):48 −57 .Chu G B, Chen H Y, Falloon T J, et al . Early Cretaceous mantle upwelling and melting of juvenile lower crust in the Middle-Lower Yangtze River Metallogenic Belt: Example from Tongshankou Cu-(Mo W) ore deposit[J]. Gondwana Research,2020 ,83 :183 −200 .Griffin W L, Pearson N J, Belousova E, et al . The Hf isotope composition of cratonic mantle: LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites[J]. Geochimica et Cosmochimica Acta,2000 ,64 (1 ):133 −147 .Griffin W L, Wang X, Jackson S E, et al . Zircon chemistry and magma mixing, SE China; in-situ analysis of Hf isotopes, Tonglu and Pingtan igneous complexes[J]. Lithos,2002 ,61 (3−4 ):237 −269 .Guo J L, Wu Y B, Gao S, et al . Episodic Paleoarchean-Paleoproterozoic (3.3–2.0 Ga) granitoid magmatism in Yangtze Craton, South China: Implications for late Archean tectonics[J]. Precambrian Research,2015 ,270 :246 −266 .Hu Z C, Liu Y S, Gao S, et al . Improved in situ Hf isotope ratio analysis of zircon using newly designed X skimmer cone and Jet sample cone in combination with the addition of nitrogen by laser ablation multiple collector ICP-MS[J]. Journal of Analytical Atomic Spectrometry,2012 ,27 :1391 −1399 .Li J W, Vasconcelos P M, Zhou M F, et al . Longevity of magmatic–hydrothermal systems in the Daye Cu–Fe–Au District, eastern China with implications for mineral exploration[J]. Ore Geology Reviews,2014a ,57 :375 −392 .Li J W, Zhao X F, Zhou M F, et al . Vasconcelos, P. Late Mesozoic magmatism from the Daye region, eastern China: U–Pb ages, petrogenesis, and geodynamic implications[J]. Contributions to Mineralogy and Petrology,2009 ,157 (3 ):383 −409 .Li J W, Zhao X F, Zhou M F, et al . Origin of the Tongshankou porphyry–skarn Cu–Mo deposit, eastern Yangtze craton, Eastern China: geochronological, geochemical, and Sr–Nd–Hf isotopic constraints[J]. Mineralium Deposita,2008 ,43 (3 ):315 −336 .Li L M, Lin S F, Davis D W, et al . Geochronology and geochemistry of igneous rocks from the Kongling terrane: Implications for Mesoarchean to Paleoproterozoic crustal evolution of the Yangtze Block[J]. Precambrian Research,2014b ,255 :30 −47 .Li X H, Li W X, Wang X C, et al . SIMS U–Pb zircon geochronology of porphyry Cu–Au–(Mo) deposits in the Yangtze River Metallogenic Belt, eastern China: Magmatic response to early Cretaceous lithospheric extension[J]. Lithos,2010 ,119 (3-4 ):427 −438 .Liu Y S, Hu Z C, Gao S, et al . In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J]. Chemical Geology,2008 ,257 (1−2 ):34 −43 .Ludwig K R . Isoplot 3.00: A geochronological toolkit for microsoft excel[J]. Berkeley Geochronology Center Special Publication,2003 ,4 :70 .Söderlund U, Patchett P J, Vervoort J D, et al . The 176Lu decay constant determined by Lu–Hf and U–Pb isotope systematics of Precambrian mafic intrusions[J]. Earth and Planetary Science Letters,2004 ,219 (3-4 ):311 −324 .Wang L J, Griffin W L, Yu J H, et al . Precambrian crustal evolution of the Yangtze Block tracked by detrital zircons from Neoproterozoic sedimentary rocks[J]. Precambrian Research,2010 ,177 (1-2 ):131 −144 .Xie G Q, Mao J W, Li X W, et al . Late Mesozoic bimodal volcanic rocks in the Jinniu basin, Middle–Lower Yangtze River Belt (YRB), East China: Age, petrogenesis and tectonic implications[J]. Lithos,2011b ,127 (1−2 ):144 −164 .Xie G Q, Mao J W, Zhao, H . J. Zircon U–Pb geochronological and Hf isotopic constraints on petrogenesis of Late Mesozoic intrusions in the southeast Hubei Province, Middle–Lower Yangtze River belt (MLYRB), East China[J]. Lithos,2011a ,125 (1−2 ):693 −710 .Yan J, Liu J M, Li Q Z, et al . In situ zircon Hf-O isotopic analyses of late Mesozoic magmatic rocks in the Lower Yangtze River Belt, central eastern China: Implications for petrogenesis and geodynamic evolution[J]. Lithos,2015 ,227 :57 −76 .Zhang S T, Ma Q, Chen H Y, et al . Petrogenesis of Early Cretaceous granitoids and mafic microgranular enclaves from the giant Tonglushan Cu–Au–Fe skarn orefield, Eastern China[J]. Lithos,2021a ,392-393 :106103 .Zhang S T, Ma Q, Chen H Y, et al . Precambrian crust growth and reworking of the eastern Yangtze Craton: insights from xenocrystic zircons in the lamprophyres from the Middle–Lower Yangtze Belt, China[J]. Precambrian Research,2021b ,355 :106121 .Zhao J H, Zhou M F, Yan D P, et al . Reappraisal of the ages of Neoproterozoic strata in south China; no connection with the Grenvillian Orogeny[J]. Geology,2011 ,39 (4 ):299 −302 .Zheng J P, Griffin W L, O'Reilly S Y, et al . Widespread Archean basement beneath the Yangtze Craton[J]. Geology,2006 ,34 (6 ):417 −420 .Zong K Q, Klemd R, Yuan Y, et al . The assembly of Rodinia: The correlation of early Neoproterozoic (ca. 900 Ma) high-grade metamorphism and continental arc formation in the southern Beishan Orogen, southern Central Asian Orogenic Belt (CAOB)[J]. Precambrian Research,2017 ,290 :32 −48 .