杨朝贵;刘燊;冯彩霞;冯光英;杨毓红;齐有强;唐亮;

• 1:中国科学院地球化学研究所矿床地球化学国家重点实验室
• 2:中国科学院研究生院

摘要(Abstract)：

锆石LA-ICP-MS U-Pb年龄(225±1.5 Ma)表明,研究区煌斑岩为印支晚期岩浆活动的产物。化学组成上,煌斑岩的SiO2含量为49.31%～52.87%,w(K2O)=0.86%～1.34%,Na2O>K2O,属钙碱性系列。MgO含量高,变化范围较大(13.11%～15.88%),Mg#=77.74～80.44),富集大离子亲石元素(LILE)(Rb、Ba、Th、U和Sr)、LREE和Pb,亏损高场强元素(HFSE)(Nb、Ta、Zr和Hf)为特征。同位素组成上,岩石具有高的(87Sr/86Sr)i(0.714697～0.716534)和负的εNd(t)(-8.55～‐9.09),表明研究区煌斑岩源区可能为EM2型地幔。此外,煌斑岩具有较高的相容元素,Cr(1161×10-6～1597×10-6),Co(60.3×10-6～77.2×10-6)和Ni(220×10-6～366×10-6)含量。综合证据表明,张家河煌斑岩来自富集的岩石圈地幔,且源区受到了来自俯冲大洋(古勉略洋)沉积物析出流体的交代作用影响。原始岩浆在上升侵位过程中存在橄榄石和单斜辉石等矿物的分离结晶作用,但没有明显的地壳混染影响。构造和地球动力学背景分析表明,研究区煌斑岩为扬子板块和南秦岭微板块碰撞后伸展拉张阶段的产物。

关键词(KeyWords)： 勉略带;煌斑岩;富集地幔;后碰撞

Abstract:

Keywords:

基金项目(Foundation): 中国科学院知识创新工程重要方向项目(KZCX2-YW-QN10);; 国家自然科学基金项目(批准号:40972071;40773020)

作者(Authors): 杨朝贵;刘燊;冯彩霞;冯光英;杨毓红;齐有强;唐亮;

DOI: 10.16461/j.cnki.1000-4734.2013.01.017

参考文献(References)：

• [1]Streckeisen A.Classification and nomenclature of volcanic rocks,lamprophyres,carbonatites and melilitic rocks IUGS subcommission on thesystematics of igneous Rocks[J].Earth and Planetary Science,1980,69:194-207.
• [2]Fowler M B,Henney P J.Mixed Caledonian appinite magmas:implications for Lamprophyre fractionation and high Ba-Sr granitegenesis[J].Contributions to Mineralogy and Petrology,1996,126:199-215.
• [3]Gibson S A,Thompson R N,Leonardos O H,et al.The Late Cretaceous impact of the Trindate mantle plume:Evidence from large-volume maficpotassic magmatism in SE Brazil[J].Journal of Petrology,1995,36:189-229.
• [4]Menzies M A,Fan W M,Zhang M.Palaeozoic and Cenozoic lithoprobes and Loss of>120 km of Archean Lithosphere,Sino-Korean Craton,China[C].Geological Society of London,1993,76:71-81.
• [5]Thompson R N,Leat P T,Dickin A P.Strongly potassic mafic magmas from lithospheric mantle sources during Continental extension and heating:Evidence from Miocene minettes of northwest Col orado,U.S.A[J].Earth and Planetary Science Letters,1989,98:139-153.
• [6]邵济安,李献华,张履桥,等.南口-古崖居中生代双峰式岩墙群形成机制的地球化学制约[J].地球化学,2001,30(6):517-524.
• [7]黄智龙,刘丛强,朱成明,王联魁,肖化云.云南老王寨金矿区煌斑岩成因及其与金矿化的关系[M].北京:地质出版社,1999:30-112.
• [8]倪师军.小秦岭基性岩脉与金矿成因关系新模式[M].成都:西南交通大学出版社,1994:12-45.
• [9]孙丰月,石准立,冯本智.胶东金矿地质及幔源C-H-O流体分异成岩成矿[M].长春:吉林人民出版社,1995:12-65.
• [10]贾大成,胡瑞忠,卢焱,谢桂青.湘东北蕉溪岭富钠煌斑岩地球化学特征[J].岩石学报,2002,18(4):459-467.
• [11]刘燊,胡瑞忠,冯彩霞,曹建劲,等.胶北晚中生代煌斑岩的岩石地球化学特征及其成因研究[J].岩石学报,2005,21(3):947-958.
• [12]晏云翔,张成立.南秦岭张家坝岩体和新院岩体地球化学特征及其形成环境[J].高校地质学报,2005,11(3):425-433.
• [13]李曙光,孙卫东,张国伟,等.南秦岭勉略构造带黑沟峡变质火山岩的年代学和地球化学-古生代洋盆及其闭合时代的证据[J].中国科学:D辑,1996,26(3):223-230.
• [14]吴峰辉,刘树文,李秋根,等.西秦岭光头山花岗岩锆石U-Pb年代学及地质意义[J].北京大学学报(自然科学版)网络版(预印本),2009,1.
• [15]王晓霞,王涛,卢欣祥,等.北秦岭老君山和秦岭梁环斑结构花岗岩及构造结构:一种可能的造山带型环斑花岗岩[J].岩石学报,2003,19(4):650-660.
• [16]张国伟,张本仁,袁学城,等.秦岭造山带与大陆动力学[M].北京:科学出版社,2001:1-855.
• [17]孙卫东,李曙光,Chen Y D,李育敬.南秦岭花岗岩错石U-Pb定年及其地质意义[J].地球化学,2000,29(3):209-216.
• [18]陕西省地质矿产局.陕西省区域地质志[M].北京:地质出版社,1989:1-637.
• [19]秦江锋,赖绍聪,李永飞.南秦岭勉县-略阳缝合带印支期光头山埃达克质花岗岩的成因及其地质意义[J].地质通报,2007,26(4):466-471.
• [20]张永清,凌文黎,李方林.峡东地区南华纪-寒武纪地层风化过程元素及Sr-Nd同位素演化特征及其地球化学意义[J].地球科学,2008,33(3):301-312.
• [21]Liu Y S,Hu Z C,Gao S,Günther D,Xu J,Gao C G,Chen H H.In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MSwithout applying an internal standard[J].Chemical Geology,2008,257:34-43.
• [22]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):589-604.
• [23]程彦博,毛景文,陈懋弘,等.云南个旧锡矿田碱性岩和煌斑岩LA-ICP-MS锆石U-Pb测年及其地质意义[J].中国地质,2008,35(6):1138-1149.
• [24]李献华,周汉文,韦刚健,等.滇西新生代超钾质煌斑岩的元素和Sr-Nd同位素特征及其对岩石圈地幔组成的制约[J].地球化学,2002,31(6):26-34.
• [25]Sun S-s,McDonough W F.Chemical and isotopic systematics of oceanic basalts:Implications for mantle composition and processes[A].Saunders A D,Norry M J.Magmatism in the Ocean Basins[C].Geol Soc Spec Publ,1989,42:313 345.
• [26]冯光英,刘燊,钟宏,贾大成,齐有强,等.吉林晚古生代榆木川基性岩的地球化学特征及其岩石成因[J].地球化学,2010,39(6):427-438.
• [27]刘燊,胡瑞忠,赵军红,等.鲁西晚中生代基性脉岩的成因和源区性质:岩石学和地球化学[J].地质评论,2004,50(6):577-586.
• [28]Mohr P A.Crustal contamination in mafic sheets:A summary[A].Halls H C,Fahrig W C.Mafic Dyke Swarms[C].SpecialPublication-Geological Association of Canada,1987,34:75-80.
• [29]Wood D A,Tarneu J,Varet J,et al.Geochemistry of basalts drills in the North Atlantic by IPOD Leg 49:Implications for mantleheterogeneity[J].Earth Planetary Science Letters,1979,42:77-97.
• [30]Bor-ming J,Fuyuan W,Ching-Hua L,et al.Crust–mantle interaction induced by deep subduction of the continental crust:Geochemical and Sr–Ndisotopic evidence from post-collisional mafic–ultramafic intrusions of the northern Dabie complex,central China[J].Chem Geo,1999,157:119-146.
• [31]Brandon A D,Hoopper P R,Goles G G,et al.Evaluating crustal contamination in continental basahs:The isotopic composition of the PictureGorge basalt of the Columbia River Basalt group Contrib[J].Minera Petrol,1993,114:452-464.
• [32]Mllnker C.Nb/Ta fractionation in a Cambrian arc/back system,New Zealand:source constraints and application of refined ICPMS techniques[J].Chem Geo,1998,144:23-45.
• [33]刘燊,胡瑞忠,赵军红,等.胶东北部碱性超基性脉岩地球化学特征及环境和成因探讨[J].地质科学,2005,40(1):69-83.
• [34]Weaver B L.The origin of oceanic basalt end-member compositions:Trace element and isotopic constrains[J].Earth and Planetary ScienceLetters,1991,104:381-397.
• [35]胡国辉,胡俊良,陈伟,赵太平.华北克拉通南缘中条山-嵩山地区1.78Ga基性岩墙群的地球化学特征及构造环境[J].岩石学报,2010,26(5):1563-1576.
• [36]Johnson M C,Plank T.Dehydration and melting experiments constrain the fate of subducted sediments[Z].Geochem Geophys Geosys Paper No,1999.
• [37]Liu S,Hu R Z,Gao S,et al.ZirconU-Pb age and Sr-Nd-Hf isotope geochemistry of Permian granodiorite and associated gabbro in the SongliaoBlock,NE China and implications for growth of juvenile crust[J].Lithos,2010,114:423-436.
• [38]Rapp R P,Shimizu N,Norman M D.Growth of early continental crust by partial melting of eclogite[J].Nature,2003,425:605-609.
• [39]Gao S,Luo T C,Zhang B R,Zhang H F,Han Y W,Zhao Z D,Hu Y K.Chemical composition of the continental crust as revealed by studies inEast China[J].Geochim Cosmochem Acta,1998,62:1959-1975.
• [40]Gurenko A A,Chaussidon M.Enriched and depleted primitivemelts included in olivine from Icelandic tholeiites:Origin bycontinuous melting of asingle mantle column[J].Geochim Cosmochem Acta,1995,59:2905-2917.
• [41]Johnson K T M.Experimental determination of partition coefficients for rare earth and high-field-strength elements between clinopyroxene,garnet,and basaltic melt at high pressure[J].Contrib Mineral Petrol,1998,133:60-68.
• [42]Zhao J H,Zhou M F.Geochemistry of Neoproterozoic mafic intrusions in the Panzhihua district(Sichuan Province,SW China):Implications forsubduction-relatedmetaso-matism in the upper mantle[J].Precamb Res,2007,152:27-47.
• [43]Liu S,Su W C,Hu R Z,Feng C X,et al.Geochronological and geochemical constraints on thepetrogenesis of alkaline ultramafic dykes fromsouthwestGuizhou Province,SW China[J].Lithos,2010,114:253-264.
• [44]Pearce J A,Peate D W.Tectonic implications of the composition of volcanic arc magmas[J].Annu Rev Earth Planet Sci,1995,23:251-285.
• [45]Münker C.The isotope and trace element budget of the Cambrian Devil River arc system,New Zealand:Identificationof four source components[J].J Petrol.,2000,41:759-788.
• [46]冯光英,刘燊,冯彩霞,等.吉林红旗岭超基性岩体的锆石U-Pb年龄、Sr-Nd-Hf同位素特征及岩石成因[J].岩石学报,2011,27(5):594-606.
• [47]McKenzie D,O'Nions R K.Partial melt distributions from inversion of rare earth element concentrations[J].J Petrol,1991,32:1021-1091.
• [48]Kinzler R J.Melting of mantle peridotite at pressures approaching the spinel to garnet transition:Application to mid-ocean ridge basaltpetrogenesis[J].J Geophys Res,1997,102(B1):853-874.
• [49]Walter M J.Melting of garnet peridotite and the origin of komatiite and depleted lithosphere[J].J Petrol,1998,39(1):29-60.
• [50]McKenzie D,O'Nions R K.The source regions of ocean island basalts[J].J Petrol,1995,36(1):133 159.
• [51]Ouma N,Ninomiya S,Nagasawa H.Mineral/groundmass partition coefficients for nepheline,melilite,clinopyroxene and perovskite inmelilite-nepheline basalt,Nyiragongo,Zaire[J].Geochem Jour,1981,15:221-228.
• [52]马昌前,杨坤光,唐仲华.花岗岩类岩浆动力学-理论、方法及鄂东花岗岩类例析[M].武汉:中国地质大学出版社,1994:38-48.
• [53]Liu S,Hu RZ,Gao S,Feng CX,et al.Zircon U-Pb geochronology andmajor,trace elemental and Sr-Nd-Pb isotopic geochemistry of mafic dykesin western Shandong Province,east China:Constrains on their petrogenesis and geodynamic significance[J].Chemical Geology,2008,255:329-345.
• [54]张国伟,孟庆任,赖绍聪.秦岭造山带的结构构造[J].中国科学:B辑,1995,25(9):994-1003.
• [55]夏邦栋,李培军.中国东部扬子板块同华北板块在中-晚三叠世拼接的沉积学证据[J].沉积学报,1999,14(1):12-21.
• [56]程日辉,王璞,刘万洙,等.下扬子区三叠纪最大海侵事件与扬子板块和华北板块碰撞的关系[J].海洋地质与第四纪地质,2004,24(2):542-545.
• [57]申浩澈,康维国,梁万通.华北板块和扬子板块碰撞时代的探讨[J].长春地质学院学报,1994,24(1):22-27.
• [58]冯庆来,杜远生,殷鸿福,等.南秦岭勉略蛇绿混杂岩带中放射虫的发现及其意义[J].中国科学:D辑,1996,26:78-82.
• [59]张成立,张国伟,晏云翔,等.南秦岭勉略带北光头山花岗岩体群的成因及其构造意义[J].岩石学报,2005,21(3):711-720.
• [60]秦江锋,赖绍聪,李永飞.扬子板块北缘碧口地区阳坝花岗闪长岩岩体成因研究及其地质意义[J].岩石学报,2005,21(3):697-710.
• [61]臧文娟.南秦岭造山带晚三叠世五龙岩体岩浆混合作用研究[D].西安:西北大学(硕士论文),2008.
• [62]王娟,李鑫,赖绍聪,等.印支期南秦岭西茬河、五龙岩体成因及构造意义[J].中国地质,2008,35(2):207-216.