北山磁海辉绿岩型铁矿区基性杂岩锆石U-Pb年代学及岩石成因Zircon U-Pb Geochronology and Genesis Study on the Mafic Complex from Diabase-Type Iron Deposit in Cihai,Beishan Area[KH*2/3D]
陈继平;廖群安;罗婷;张雄华;郭东宝;朱和林;柳小明;
摘要(Abstract):
磁海辉绿岩型铁矿位于塔里木北缘北山裂谷带,主要岩石类型为辉绿岩,岩石具有较高的Mg#(55.7~70.1)、中铝Al2O3(13.75~14.65)特征,Na2O/K2O(1.79~14.04)变化较大,整体属于钙碱性系列(K2O/Na2O=0.07~0.56,FeO/MgO=0.77~1.46)。稀土元素方面,磁海辉绿岩具有较高的稀土元素质量分数和δEu异常特征[w(∑REE)=88.01×10-6~213.07×10-6,δEu=0.63~1.44],球粒陨石标准化稀土元素配分模式为缓右倾型[(La/Yb)N=1.32~3.87,(La/Sm)N=1.05~2.17,(Gd/Yb)N=1.12~1.58],微量元素上选择性富集大离子亲石元素(Rb、K),亏损高场强元素(Nb、Ta)。岩浆演化过程中斜长石和单斜辉石的分离结晶作用是岩浆演化的主要机制,同时伴有较为明显的地壳混染作用。LA-ICP-MS锆石U-Pb年代学指示该辉绿岩形成于约291.9Ma,构造环境分析表明磁海辉绿岩为板内拉张环境的产物。
关键词(KeyWords): 磁海辉绿岩;锆石U-Pb;分离结晶;同化混染;拉张环境
基金项目(Foundation): 中国地质调查局地质调查项目(1212011085469)
作者(Author): 陈继平;廖群安;罗婷;张雄华;郭东宝;朱和林;柳小明;
Email:
DOI:
参考文献(References):
- [1]Zhou M F,Michael L C,Yang Z,et al.Geochemistry and petrogen-esis of 270Ma Ni-Cu-(PGE)sulfide-bearing mafic intrusions in theHuangshan district,Eastern Xinjiang,Northwest China:Implica-tions for the tectonic evolution of the Central Asian orogenic belt[J].Chemical Geology,2004,209(3):233-257.
- [2]Mao J W,Pirajno F,Zhang Z H,et al.A review of the Cu-Nisulphide deposits in the Chinese Tianshan and Altay orogens(Xinjiang Autonomous Region,NW China):Principal charac-teristics and ore-forming processes[J].Journal of Asian EarthSciences,2008,32(2/4):184-203.
- [3]Han C,Xiao W,Zhao G,et al.In-situ U-Pb,Hf and Re-Os iso-topic analyses of the Xiangshan Ni-Cu-Co deposit in EasternTianshan(Xinjiang),Central Asia Orogenic Belt:Constraintson the timing and genesis of the mineralization[J].Lithos,2010,120(3):547-562.
- [4]Qin K Z,Zhang L C,Xiao W J,et al.Overview of major Au,Cu,Niand Fe deposits and metallogenic evolution of the eastern TianshanMountains,Northwestern China[C]∥Mao J W,Goldfrab R J,Seltmann R.Tectonic evolution and metallogeny of the Chinese Al-tay and Tianshan.London:[s.n.],2003:227-249.
- [5]Qin K,Su B,Sakyi P A,et al.SIMS zircon U-Pb geochronologyand Sr-Nd isotopes of Ni-Cu-bearing mafic-ultramafic intru-sions in Eastern Tianshan and Beishan in correlation with floodbasalts in Tarim Basin(NW China):Constraints on a ca.280Ma mantle plume[J].American Journal of Science,2011,311(3):237-260.
- [6]夏明哲,姜常义,钱壮志,等.新疆东天山葫芦岩体岩石学与地球化学研究[J].岩石学报,2008,24(12):2749-2760.
- [7]王玉往,王京彬,王莉娟,等.新疆哈密黄山地区铜镍硫化物矿床的稀土元素特征及意义[J].岩石学报,2004,20(4):935-948.
- [8]肖庆华,秦克章,唐冬梅,等.新疆哈密香山西铜镍-钛铁矿床系同源岩浆分异演化产物:矿相学,锆石U-Pb年代学及岩石地球化学证据[J].岩石学报,2010,26(2):503-522.
- [9]顾连兴,王金珠.造山带环境中的东疆型镁铁—超镁铁杂岩[J].岩石学报,1994,10(4):339-355.
- [10]邓宇峰,宋谢炎,陈列锰,等.东天山黄山西含铜镍矿镁铁-超镁铁岩体岩浆地幔源区特征研究[J].岩石学报,2012,27(12):3640-3652.
- [11]苏本勋,秦克章,孙赫,等.新疆北山地区旋窝岭镁铁-超镁铁岩体的年代学,岩石矿物学和地球化学研究[J].岩石学报,2010,26(11):3283-3294.
- [12]苏本勋,秦克章,唐冬梅,等.新疆北山地区坡十镁铁-超镁铁岩体的岩石学特征及其对成矿作用的指示[J].岩石学报,2012,27(12):3627-3639.
- [13]唐萍芝,王京彬,王玉往,等.新疆磁海铁矿区镁铁-超镁铁岩地球化学特征及其地质意义[J].地球化学,2010,39(6):542-552.
- [14]薛春纪,姬金生.新疆磁海铁(钴)矿床次火山热液成矿学[J].矿床地质,2000,19(2):156-164.
- [15]赵玉社.新疆磁海铁矿床地质特征及矿床成因[J].西北地质,2000,33(1):31-38.
- [16]王玉往,沙建明,程春.新疆磁海铁(钴)矿床磁铁矿成分及其成因意义[J].2006,25(增刊):321-324.
- [17]Pirajno F,Mao J,Zhang Z,et al.The association of mafic-ultra-mafic intrusions and A-type magmatism in the Tian Shan andAltay orogens,NW China:Implications for geodynamic evolu-tion and potential for the discovery of new ore deposits[J].Journal of Asian Earth Sciences,2008,32(2/4):165-183.
- [18]左国朝,于守南,李秋林.新疆磁海铁矿床产出特征及成矿构造演化[J].西北地质,2004,37(2):53-61.
- [19]Liu Y,Hu Z,Gao S,et al.In situ analysis of major and trace ele-ments of anhydrous minerals by LA-ICP-MS without applying aninternal standard[J].Chemical Geology,2008,257(1/2):34-43.
- [20]Zong K,Liu Y,Gao C,et al.In situ U-Pb dating and trace elementanalysis of zircons in thin sections of eclogite:Refining constraintson the ultra high-pressure metamorphism of the Sulu terrane,China[J].Chemical Geology,2010,269(3/4):237-251.
- [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):1589-1604.
- [22]Le Bas M J,Le Maitre R W,Streckeisen A,et al.A chemicalclassification of volcanic rocks based on the total alkali-silicadiagram[J].Journal of Petrology,1986,27(3):745-750.
- [23]Berlman I B.Handbook of fluorescence spectra of aromaticmolecules[M].New York:ACS Publications,1971.
- [24]Sun S S,Mcdonough W F.Chemical and isotopic systematics ofoceanic basalts:Implications for mantle composition andprocesses[J].Geological Society,London,Special Publications,1989,42(1):313-345.
- [25]Hofmann A W.Chemical differentiation of the Earth:The rela-tionship between mantle,continental crust,and oceanic crust[J].Earth and Planetary Science Letters,1988,90(3):297-314.
- [26]陈毓川.中国天山矿产及成矿体系[M].北京:地质出版社,2008.
- [27]胡霭琴,张国新.新疆大陆基底分区模式和主要地质事件的划分[J].新疆地质,2001,19(1):12-19.
- [28]左国朝,刘春燕.北山泥盆纪碰撞造山火山—磨拉石地质构造及地球化学特征[J].甘肃地质学报,1995,4(1):35-43.
- [29]陈升平,朱云海.新疆北山石炭纪、二叠纪火山岩岩石化学及其构造[J].地球科学:中国地质大学学报,1992,17(6):647-656.
- [30]姜常义,程松林,叶书锋,等.新疆北山地区中坡山北镁铁质岩体岩石地球化学与岩石成因[J].岩石学报,2006,22(1):115-126.
- [31]Ao S J,Xiao W J,Han C M,et al.Geochronology and geochem-istry of Early Permian mafic-ultramafic complexes in the Beis-han area,Xinjiang,NW China:Implications for late Paleozoictectonic evolution of the southern Altaids[J].Gondwana Re-search,2010,18(2/3):466-478.
- [32]Su B X,Qin K Z,Sakyi P A,et al.U–Pb ages and Hf–O i-sotopes of zircons from Late Paleozoic mafic–ultramafic unitsin the southern Central Asian Orogenic Belt:Tectonic implica-tions and evidence for an Early-Permian mantle plume[J].Gondwana Research,2011,20(2):516-531.
- [33]李华芹,陈富文,梅玉萍,等.新疆坡北基性-超基性岩带Ⅰ号岩体Sm-Nd和SHRIMP U-Pb同位素年龄及其地质意义[J].矿床地质,2007,25(4):463-469.
- [34]郑勇,陈俊,庞建材,等.新疆哈密北山黑山岭一带基性岩SHRIMP测年及地质意义[J].新疆地质,2009,27(4):320-324.
- [35]Su B X,Qin K Z,Sakyi P A,et al.Geochemistry and geochro-nology of acidic rocks in the Beishan region,NW China:Petro-genesis and tectonic implications[J].Journal of Asian EarthSciences,2011,41(1):31-43.
- [36]秦克章,方同辉.东天山板块构造分区,演化与成矿地质背景研究[J].新疆地质,2002,20(4):302-308.
- [37]Pearce J A,Norry M J.Petrogenetic implications of Ti,Zr,Y,and Nb variations in volcanic rocks[J].Contributions to miner-alogy and petrology,1979,69(1):33-47.