太行山南段洪山岩体中粗面斑岩地球化学特征及LA-ICP-MS锆石U-Pb定年
Geochemistry and LA-ICP-MS zircon U-Pb dating for trachyte porphyry of Hongshan intrusion in the southern Taihang Mountains
-
摘要: 在详细野外调研的基础上,对位于太行山南段洪山岩体中粗面斑岩的岩石学、地球化学和年代学特征进行了研究。该区斑岩中SiO2含量为63.57%~67.85%,平均为65.19%;里特曼指数σ值为5.6~8.2;K2O/Na2O为1.00~1.74,平均为1.24;A12O3为16.75%~18.77%,平均为18.21%。铝饱和指数A/CNK为1.00~1.06,属于碱性正长岩类岩石。岩石稀土元素总量(ΣREE)为33.75×10-6~144.30×10-6,(La/Yb)N=9.18~33.28,呈现轻稀土元素(LREE)富集、重稀土元素(HREE)相对亏损的特点。δEu=0.99~1.16,有微弱正Eu异常。在原始地幔标准化微量元素蜘蛛图解中,样品均显示强烈富集大离子亲石元素(LILEs)、相对亏损高场强元素(HFSEs)的特征。同时,在该地区获得的粗面斑岩LA-ICP-MS锆石U-Pb年龄为128.6±1.0Ma。锆石εHf(t)值为-16.0~-11.4,对应的地壳模式年龄(TDM)为1258~1432Ma。这些数据表明,洪山粗面斑岩与洪山其他中生代侵入岩是同期岩浆作用的产物,形成于早白垩世由造山挤压环境向伸展环境转变期,是EM1型富集地幔部分熔融形成富碱的岩浆上升侵位,并受古老下地壳物质混染形成的。华北规模庞大的中生代岩浆作用可能与部分熔融并消耗富集岩石圈地幔层有关,这可能也是岩石圈地幔减薄的重要方式之一。Abstract: Based on detailed field investigation, the authors studied the petrology, geochemistry and geochronology of trachyte porphyry in Hongshan intrusion. The SiO2 and Al2O3 of the rock range from 63.57% to 67.85% and 16.75% to 18.77%, 65.19% and 18.21% on average respectively. Rittmann index(σ) ranges 5.6~8.2, the K2O/Na2O ratio ranges 1.00~1.74, with an average of 1.24. A/CNK varies from 1.00 to 1.06. These data suggest that it belongs to alkaline syenite rock. The REE content is between 33.75×10-6 and 144.30×10-6, with(La/Yb)N ratios of 9.18~33.28 and δEu of 0.99~1.16. The intrusion is remarkably characterized by enriched LREE and depleted HREE. The chondrite-normalized REE patterns show weak positive Eu anomaly. In the primitive mantle nor-malized trace element spider diagrams, the samples show strong enrichment of LILEs and relative depletion of HFSEs. In addition, tra-chyte porphyry's LA-ICP-MS zircon U-Pb dating indicates that the trachyte porphyry were emplaced at ca.128.6±1.0Ma. The zir-con εHf(t) values(-16.0~-11.4) yielded zircon Hf crustal modal ages of 1258~1432Ma. Based on the data obtained, the authors hold that Hongshan volcanic rocks originated from partial melting of an EMI-type mantle source, contaminated by LCC. Trachyte por-phyry formed in the same time as the Hongshan intrusion in the Mesozoic Cretaceous. Magmatic activities took place in the transfor-mation period of the collision environment, causing the partial melting of the mantle and producing the trachyte porphyry. This might have been one of the important ways of lithospheric mantle thinning.
-
-
[1] Liu D Y, Nutman A P, Compston W, et al. Remnants of 3800Ma crust in the Chinese part of the Sino-Korean craton[J]. Geology, 1992, 20:339-342.
[2] Zheng J P, Griffin W L, O'Reilly S Y, et al. 3.6Ga lower crust in central China:New evidence on the assembly of the North China craton[J]. Geology, 2005, 32:229-232.
[3] 任康绪. 碱性岩研究进展述评[J].化工矿产地质, 2003, 25(3):151-163.
[4] 周玲棣,赵振华. 我国富碱侵入岩的岩石学和岩石化学特征[J].中国科学(B辑), 1994,24(10):1093-1101.
[5] 赵振华,周玲棣. 我国某些富碱侵入岩的稀土元素地球化学[J].中国科学(B辑), 1994,24(10):1109-1120.
[6] 阎国翰,许保良,牟保磊,等.中国北方中生代富碱侵入岩钕、锶、铅同位素特征及其意义[J].矿物岩石地球化学通报, 2001,20(4):234-237.
[7] Yan G H, Xu B L, Mu B L, et al. Alkaline Intrusives at the East Foot of the Taihang-Da Hinggan Mountains:Chronology, Sr-Nd-Pb Isotopic Characteristics and Their Implications[J]. Acta Geologica Sinica,2000, 4:774-780.
[8] Chen B, Jahn B M, Arakawa Y, et al. Petrogenesis of the Mesozoic intrusive complexes from the southern Taihang Orogen, North China Craton:elemental and Sr-Nd-Pb isotopic constraints[J]. Contrib Mineral Petrol, 2004, 148:459-501.
[9] Chen B, Tian W, Jahn B M, et al. Zircon SHRIMP U-Pb ages and in-situ Hf isotopic analysis for the Mesozoic intrusions in South Tai-hang, North China craton:Evidence for hybridization between mantle-derived magmas and crustal components[J]. Lithos, 2008, 102:118-137.
[10] Chen B, Jahn B M, Suzuki K. Petrological and Nd-Sr-Os isotopic constraints on the origin of high-Mg adakitic rocks from the North China Craton:Tectonic implications[J]. Geology, 2013, 41:91-94.
[11] 周凌,陈斌. 南太行洪山正长岩体的成因和意义:锆石SHRIMP年代学、化学成分和Sr-Nd同位素特征[J].自然科学进展, 2005, 15(11):1357-1365.
[12] 蔡剑辉, 阎国翰, 许保良, 等. 太行山-大兴安岭东麓晚中生代碱性侵入岩岩石地球化学特征及其意义[J].地球学报, 2006, 27(5):447-459.
[13] 郑建民. 冀南邯邢地区夕卡岩型铁矿成矿流体及成矿机制[D].北京:中国地质大学博士学位论文, 2007.
[14] Liu Y S, Hu Z C, Gao S, et al. In situ analysis of major and trace elements of an hydrous minerals b LA-ICP-MS without applying an internal standard[J]. Chemical Geology, 2008, 257(1/2):34-43.
[15] 李怀坤,朱士兴,相振群,等. 北京延庆高于庄组凝灰岩的锆石UPb定年研究及其对华北北部中元古界划分新方案的进一步约束[J].岩石学报, 2010, 26(7):2131-2140.
[16] Liu Y S, Hu Z C, Zong K Q, et al. Reappraisement and refine-ment of zircon U-Pb isotope and trace element analyses by LAICP-MS[J]. Chinese Science Bulletin, 2010, 55(15):1535-1546.
[17] Ludwig K R. User's Manual for Isoplot 3.0:A Geochronological Toolkit for Microsoft Excel[M]. Berkeley Geochronology Center:Special Publication, 2003, 4:1-71.
[18] Andersen T. Correction of common lead in U-Pb analyses that do not report 204Pb[J]. Chemical Geology, 2002, 192(1/2):56-79.
[19] 侯可军,李延河,邹天人,等. LA-MC-ICP-MS锆石Hf同位素的分析方法及地质应用[J].岩石学报,2007,23(10):2595-2604.
[20] Morel M L A, Nebel O, Nebel-Jacobsen Y J, et al. Hafnium isotope characterization of the GJ-1 zircon reference material by solution and laser-ablation MC-ICPMS[J]. Chemical geology, 2008, 255:231-235.
[21] 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):1588-1604.
[22] Vavra G, Gebauer D, Schmid R. Multiple zircon growth and recrystallization during polyphase Late Carboniferous to Triassic metamorphism in granulates of the Ivrea Zone(Southern Alps):An-ion microprobe(SHRIMP) study[J]. Contrib. Mineral. Petrol., 1996, 122:337-358.
[23] 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.
[24] 朱丹,肖龙,孙熠,等. 邯邢地区矿山村、洪山岩体特征及其与矽卡岩成矿的关系[J].高校地质学报, 2013, 19:208.
[25] 罗照华,邓晋福,韩秀卿. 太行山造山带岩浆活动及其造山过程反演[M].北京:地质出版社,1999:1-124.
[26] Ewans O C, Hanson G N. Accessory-mineral fraction of rare earth element abundance in granitoid rock[J].Chemical Geology, 1993, 110:69-93.
[27] Hanson J N. The application of trace elements to the petrogenesis of igneous rocks of granitic composition[J]. Earth and Planetary Science Letters, 1978, 38:26-43.
[28] Downes H. Formation and modification of the shallow subconti-nental lithospheric mantle:a review of geochemical evidence from ultramafic xenolith suites and tectonically emplaced ultramafic massifs of western and central Europe[J]. Journel of Petrology, 2001, 42:233-250.
[29] Ma C, Li Z, Ehlers C, et al. A post collisional magmatic plumbing system:Mesozoic granitoid plutons from the Dabieshan high pres-sure and ultrahigh pressure metamorphic zone, east central China[J]. Lithos, 1998,45:431-456.
[30] Canning J C, Henney P J, Morrison M A, et al. Geochemistry of late Caledonian minettes from Northern Britain:implications for the Caledonian sub-continental lithospheric mantle[J]. Mineralogi-cal Magazine, 1996, 60:221-236.
[31] Molzahn M, Reisberg L,Worner G. Os, Sr, Nd, Pb,O isotope and trace element data from the Ferrar flood basalts, Antarctica:evidence for an enriched subcontinental lithospheric source[J]. Earth Planet Sci. Lett., 1996, 144:529-546.
[32] Allegre C J, Minster J F. Quantitative method of trace element behavior in magmatic processes[J]. Earth Planet Sci. Lett., 1978, 38:1-25.
[33] Fan W M, Zhang H F, Baker J, et al. On and off the North China Craton; where is the Archaean keel[J]. Petrology, 2000, 41(7):933-950.
[34] Xu Y G. Thermo-tectonic destruction of the Archean lithospheric keel beneath the Sino-Korean craton in China Evidence timing and mechanism[J]. Phys. Chem. Earth(A), 2001, 26(9/10):747-757.
[35] 吴福元,孙德有. 中国东部中生代岩浆作用与岩石圈减薄[J].长春科技大学学报, 1999, 29(4):313-318.
[36] 吴福元,孙德有,张广良,等. 论燕山运动的深部地球动力学本质[J]. 高校地质学报, 2000,6(3):379-388.
[37] 吴福元,葛文春,孙德有,等. 中国东部岩石圈减薄研究中的几个问题[J]. 地学前缘, 2003,10(3):51-60.
[38] 涂光炽.关于富碱侵入岩[J].矿产与地质,1989, 3(3):1-4.
[39] 陈斌,田伟,翟明国,等. 太行山和华北其它地区中生代岩浆作用的锆石U-Pb年代学和地球化学特征及其岩浆成因和地球动力学意义[J]. 岩石学报, 2005, 21(1):13-24.
[40] Menzies M A, Fan W, Zhang M. Palaeozoic and Cenozoic litho-probes and loss of >120km of Archean lithosphere, Sino-Korean craton, China[J]. Geological Society of London Special Publication, 1993:76-71.
-
计量
- 文章访问数: 1366
- PDF下载数: 140
- 施引文献: 0
下载: