辽东大东沟金矿岩浆岩LA-ICP-MS锆石U-Pb年龄及岩石地球化学特征
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摘要
大东沟金矿位于华北克拉通北缘东段。对矿区内的岩浆岩进行了锆石U-Pb年代学和岩石地球化学研究。用LAICP-MS方法,测得花岗闪长岩和石英闪长岩中锆石207Pb/206Pb年龄加权平均值分别为2147±10Ma和140.8±1.2Ma,花岗闪长岩经历了1874±18Ma的后期热液活动事件。元素地球化学测试结果显示,两者均为高钾钙碱性I型花岗岩类。石英闪长岩稀土元素配分模式为明显的右倾模式,具有弱负Eu异常,而花岗闪长岩为平坦的右倾模式,具有明显的正Eu异常,两者呈现轻稀土相对富集的特征。微量元素均富集Rb、Ba、K等大离子亲石元素。石英闪长岩表现为亏损Nb、Ta、Zr、Hf、Ti等高场强元素,而花岗闪长岩表现为Th、Nb、Ta、Ti等高场强元素亏损。结合区域大地构造背景及相关研究认为,花岗闪长岩形成于大陆弧后盆地的构造背景,主要是由约2.2Ca的岩浆底侵加热导致下地壳基性火成岩部分熔融而成;石英闪长岩形成于伊佐奈岐板块向华北板块斜向俯冲的构造背景,具有壳幔混合的特征,为俯冲带流体交代地幔,使其部分熔融,形成基性岩浆与地壳熔融物质混合而成的产物。
The Dadonggou gold deposit is located in the east of the northern margin of North China craton.In this paper,zircon UPb chronology and petrochemistry of magmatite from the Donggou gold deposit were studied. The LA-ICP-MS method was used and the ages of zircon in granodiorite and quartz diorite are 2147±10 Ma(207 Pb/206 Pb age-weighted mean,n=17,MSWD=0.59)and140.8±1.2 Ma(206 Pb/238 U age-weighted mean,n=22,MSWD=0.48)respectively; nevertheless, the granite diorite experienced late hydrothermal events of 1874 ± 18 Ma.Elemental geochemical test results show that both granodiorite and quartz diorite are high potassium calc-alkaline I type granite. Quartz diorite is a right-dipping model with weak negative Eu anomalies,but granodiorite is a relatively flat right-dipping model with obvious positive Eu anomalies; they both show characteristics of relatively rich light rare earth elements. As for trace elements,they are all enriched in large ion lithophile elements Rb,Ba and K. Quartz diorite is characterized by depletion of high field strength elements such as Nb,Ta,Zr,Hf and Ti,but the granodiorite shows the depletion of high field strength elements such as Th,Nb,Ta and Ti. Combined with regional tectonic evolution and related studies,the authors have reached the conclusion that granodiorite was formed in the tectonic background of continental back-arc basin,mainly caused by partial melting of the lower crustal igneous rocks due to the magmatic heating action of ～2.2 Ca. However,quartz diorite was formed in the tectonic background of the oblique subduction of Izanagi plate to the North China plate,which had the feature of crust-mantle mixing.It was the fluid metasomatic mantle in the subduction zone,and the basic magma formed by partial melting was mixed with the crust molten material.
The Dadonggou gold deposit is located in the east of the northern margin of North China craton.In this paper,zircon UPb chronology and petrochemistry of magmatite from the Donggou gold deposit were studied. The LA-ICP-MS method was used and the ages of zircon in granodiorite and quartz diorite are 2147±10 Ma(207 Pb/206 Pb age-weighted mean,n=17,MSWD=0.59)and140.8±1.2 Ma(206 Pb/238 U age-weighted mean,n=22,MSWD=0.48)respectively; nevertheless, the granite diorite experienced late hydrothermal events of 1874 ± 18 Ma.Elemental geochemical test results show that both granodiorite and quartz diorite are high potassium calc-alkaline I type granite. Quartz diorite is a right-dipping model with weak negative Eu anomalies,but granodiorite is a relatively flat right-dipping model with obvious positive Eu anomalies; they both show characteristics of relatively rich light rare earth elements. As for trace elements,they are all enriched in large ion lithophile elements Rb,Ba and K. Quartz diorite is characterized by depletion of high field strength elements such as Nb,Ta,Zr,Hf and Ti,but the granodiorite shows the depletion of high field strength elements such as Th,Nb,Ta and Ti. Combined with regional tectonic evolution and related studies,the authors have reached the conclusion that granodiorite was formed in the tectonic background of continental back-arc basin,mainly caused by partial melting of the lower crustal igneous rocks due to the magmatic heating action of ～2.2 Ca. However,quartz diorite was formed in the tectonic background of the oblique subduction of Izanagi plate to the North China plate,which had the feature of crust-mantle mixing.It was the fluid metasomatic mantle in the subduction zone,and the basic magma formed by partial melting was mixed with the crust molten material.
引文
[1]陈荣度，李显东，张福生.对辽东古元古代地质若干问题的讨论[J].中国地质，2003,(2):207-213.
[2]陈荣度.辽东裂谷的地质构造演化[J].中国区域地质，1990,(4):306-315, 333.
[3]Qi L,Hu J,Gregoire D C. Determination of trace elements in granites by inductively coupled plasma mass spectrometry[J].Talanta,2000,51(3):507-513.
[4]李晓彪.热电离质谱（TIMS）的Sr-Nd-Pb同位素标样测定[J].矿物学报，2009,29(S1):609-610.
[5]Jackson S E,Pearson N J,Grifin W L,et al. The application of laser ablation-inductively coupled plasma-masss spectrometry to in situ U-Pb zircon geochronology[J].Chemical Geology,2004,211:47-69.
[6]Slama J,Kosler J,Condon D J,et al. Plesovicezircon:A new natural reference material for U-Pb and Hf isotopic microanalysis[J].Chemical Geology,2008,249(1/2):1-35.
[7]Ludwig K R.User's manual for Isoplot 3.00:Ageochronological toolkit for Microsoft Excel[M].Berkeley Geochronology Center Special Publication,2003.
[8]Rubatto D,Gebauer D. Use of Cathodoluminescence for U-Pb Zircon Dating by Ion Microprobe:Some Examples from the Western Alps, Germany:Cathodoluminescence in Geosciences[M].Springer-Verlag Berlin Heidelberg,2000:373-400.
[9]Moller A,O'Brien P J,Kennedy A,et al. Linking growth episodes of zircon and metamorphic textures to zircon chemistry:an example from the ultrahigh-temperature granulites of Rogaland(SW Norway)[J].Geological Society of London Special Publications,2003,220(1):65-81.
[10]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,(16):1589-1604.
[11]Rickwood P C. Boundary Lines Within Petrologic Diagrams Which Use Oxides of Major and Minor Elements[J].Lithos,1989,22(4):247-263.
[12]Maniar P D,Piccoli P M. Tectonic Discrimination of Granitoids[J].Geological Society of America Bulletin,1989,101(5):635-643.
[13]Sun S S, McDonough W F. Chemical and isotopm systematics of oceanic basalts:Implications for mantle composition and processes[C]//Saunders A D, Vony M J. Magmatism in the Ocean Basins.Geological Society Special Puhlications,1989,42(1):313-345.
[14]孟恩，刘福来，刘平华，等.辽东半岛东北部宽甸地区南辽河群沉积时限的确定及其构造意义[J].岩石学报，2013,29(7):2465-2480.
[15]陈斌，李壮，王家林，等.辽东半岛~2.2Ga岩浆事件及其地质意义[J].吉林大学学报（地球科学版），2016,46(2):303-320.
[16]刘福来，刘平华，王舫，等.胶-辽-吉古元古代造山/活动带巨量变沉积岩系的研究进展[J].岩石学报，2015,31(10):2816-2846.
[17]李壮，陈斌，刘经纬，等.辽东半岛南辽河群锆石U-Pb年代学及其地质意义[J].岩石学报，2015,31(6):1589-1605.
[18]王舫，刘福来，刘平华，等.南辽河群盖县组的重新厘定：来自辽南地区黄花甸—苏子沟一带变质砂岩碎屑锆石U-Pb年代学证据[J].岩石学报，2018,34(4):1219-1228, 1248-1253.
[19]聂飞，董国臣，莫宣学，等.滇西昌宁-孟连带三叠纪花岗岩地球化学、年代学及其意义[J].岩石学报，2012,28(5):1465-1476.
[20]Whalen J B,Currie K L,Chappell B W. A-type granites:geochemical characteristics,discrimination and petrogenesis[J].Contributions Mineralogy Petrology,1987,95:407-419.
[21]Chappell B,White A J R. I-and S-type granites in the Lachlan Fold Belt[J].Transactious of the Royal Society of Edinburgh.Earth Sciences,1992,83:1-26.
[22]Cornell D H,Schutte S S,Eglington R L. The Ongeluk Basaltic Andesite Formation in Grigualanel West South Africa Submarine Alteration in a 2222Ma Proterozoic Sea[J].Precambrain Research,1996,79(1/2):102-123.
[23]McKenzie D. Some Remarks on the Movement of Small Melt Fractions in the Mantle[J].Earth and Planetary Science Letters,1989,95(1):53-72.
[24]Taylor S R,McLennan S M. The geochemical evolution of the continental crust[J]. Reviews of Geophysics,1995,33(2):241-265.
[25]Barth M G,McDonough W F,Rudnick R L. Tracking the budget of Nb and Ta in the continental crust[J].Chemical Geology,2000,165:197-213.
[26]张秋生，杨振升，刘连登.辽东半岛早期地壳与矿床[M].北京:地质出版社，1988:218-450.
[27]李三忠，郝德峰，赵国春，等.丹东花岗岩的地球化学特征及其成因[J].岩石学报，2004,(6):116-122.
[28]Li S Z,Zhao G C,Sun M,et al. Deformation history of the Paleoproterozoic Liaohe assemblage in the Eastern block of the North China Craton[J].Journal of Asian Earth Sciences,2005,24(5):659-674.
[29]Li S Z,Zhao G C,Sun M,et al. Are the South and North Liaohe Groups of North China Craton different exotic terranes-Nd isotope constraints[J].Gondwana Research,2006,9(1):198-208.
[30]Li S Z,Zhao G C. SHRIMP U-Pb zircon geochronology of the Liaoji granitoids:Constraints on the evolution of the Paleoproterozoic Jiao-Liao-Ji belt in the Eastern Block of the North China Craton[J].Precambrian Research,2007,158(1):1-16.
[31]Luo Y,Sun M,Zhao G C,et al. LA-ICP-MS U-Pb zircon ages of the Liaohe Group in the Eastern Block of the North China Craton:Constraints on the evolution of the Jiao-Liao-Ji Belt[J].Precambrian Research,2004,134(3/4):349-371.
[32]Luo Y,Sun M,Zhao G C,et al. A comparison of U-Pb and Hf isotopic compositions of detrital zircons from the North and South Liaohe Groups:Constraints on the evolution of the Jiao-Liao-Ji Belt,North China Craton[J].Precambrian Research,2008,163(3/4):279-306.
[33]白瑾.中国前寒武纪地壳演化[M].北京：地质出版社，1993:47-89.
[34]Faure M,Lin W,MoniéP,et al. Palaeoproterozoic arc magmatism and collision in Liaodong Peninsula,NE China[J].Terra Nova,2004,16(2):75-80.
[35]Lu X P,Wu F Y,Guo J H,et al. Zircon U-Pb geochronological constraints on the Paleoproterozoic crustal evolution of the Eastern block in the North China Craton[J].Precambrian Research,2006,146(3/4):138-164.
[36]王惠初，陆松年，初航，等.辽阳河栏地区辽河群中变质基性熔岩的锆石U-Pb年龄与形成构造背景[J].吉林大学学报（地球科学版），2011,41(5):1322-1334,1361.
[37]Meng E,Liu F L,Liu P H,et al. Petrogenesis and tectonic significance of Paleoproterozoic meta-mafic rocks from central Liaodong Peninsula,Northeast China:Evidence from zircon U-Pb dating and in situ Lu-Hf isotopes,and whole-rock geochemistry[J].Precambrian Research,2014,247:92-109.
[38]Li Z, Chen B. Geochronology and geochemistry of the Paleoproterozoic meta-basalts from the Jiao-Liao-Ji Belt,North China Craton:Implications for petrogenesis and tectonic setting[J].Precambrian Research,2014,255:653-667.
[39]贺高品，叶慧文.辽东—吉南地区早元古代变质地体的组成及主要特征[J].长春科技大学学报，1998,(2):2-7,15.
[40]贺高品，叶慧文.辽东—吉南地区早元古代两种类型变质作用及其构造意义[J].岩石学报，1998,(2):25-35.
[41]Zhao G C,Cawood P A,Li S Z,et al. Amalgamation of the North China Craton:Key issues and discussion[J]. Precambrian Research,2012,222-223:55-76.
[42]Pearce J A,Harris N B W,Tindle A G. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks[J].Journal of Petrology,1984,25:956-983.
[43]郝德峰，李三忠，赵国春，等.辽吉地区古元古代花岗岩成因及对构造演化的制约[J].岩石学报，2004,(6):108-115.
[44]孙敏，张立飞，吴家弘.早元古代宽甸杂岩的成因：地球化学证据[J].地质学报，1996,(3):207-222.
[45]葛肖虹，刘俊来，任收麦，等.中国东部中—新生代大陆构造的形成与演化[J].中国地质，2014,41(1):19-38.
[46]毛景文，谢桂青，张作衡，等.中国北方中生代大规模成矿作用的期次及其地球动力学背景[J].岩石学报，2005,(1):171-190.
[47]杨宽，王建平，林进展，等.胶东半岛艾山岩体岩石地球化学特征及成因意义[J].地质与勘探，2012,48(4):693-703.
[2]陈荣度.辽东裂谷的地质构造演化[J].中国区域地质，1990,(4):306-315, 333.
[3]Qi L,Hu J,Gregoire D C. Determination of trace elements in granites by inductively coupled plasma mass spectrometry[J].Talanta,2000,51(3):507-513.
[4]李晓彪.热电离质谱（TIMS）的Sr-Nd-Pb同位素标样测定[J].矿物学报，2009,29(S1):609-610.
[5]Jackson S E,Pearson N J,Grifin W L,et al. The application of laser ablation-inductively coupled plasma-masss spectrometry to in situ U-Pb zircon geochronology[J].Chemical Geology,2004,211:47-69.
[6]Slama J,Kosler J,Condon D J,et al. Plesovicezircon:A new natural reference material for U-Pb and Hf isotopic microanalysis[J].Chemical Geology,2008,249(1/2):1-35.
[7]Ludwig K R.User's manual for Isoplot 3.00:Ageochronological toolkit for Microsoft Excel[M].Berkeley Geochronology Center Special Publication,2003.
[8]Rubatto D,Gebauer D. Use of Cathodoluminescence for U-Pb Zircon Dating by Ion Microprobe:Some Examples from the Western Alps, Germany:Cathodoluminescence in Geosciences[M].Springer-Verlag Berlin Heidelberg,2000:373-400.
[9]Moller A,O'Brien P J,Kennedy A,et al. Linking growth episodes of zircon and metamorphic textures to zircon chemistry:an example from the ultrahigh-temperature granulites of Rogaland(SW Norway)[J].Geological Society of London Special Publications,2003,220(1):65-81.
[10]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,(16):1589-1604.
[11]Rickwood P C. Boundary Lines Within Petrologic Diagrams Which Use Oxides of Major and Minor Elements[J].Lithos,1989,22(4):247-263.
[12]Maniar P D,Piccoli P M. Tectonic Discrimination of Granitoids[J].Geological Society of America Bulletin,1989,101(5):635-643.
[13]Sun S S, McDonough W F. Chemical and isotopm systematics of oceanic basalts:Implications for mantle composition and processes[C]//Saunders A D, Vony M J. Magmatism in the Ocean Basins.Geological Society Special Puhlications,1989,42(1):313-345.
[14]孟恩，刘福来，刘平华，等.辽东半岛东北部宽甸地区南辽河群沉积时限的确定及其构造意义[J].岩石学报，2013,29(7):2465-2480.
[15]陈斌，李壮，王家林，等.辽东半岛~2.2Ga岩浆事件及其地质意义[J].吉林大学学报（地球科学版），2016,46(2):303-320.
[16]刘福来，刘平华，王舫，等.胶-辽-吉古元古代造山/活动带巨量变沉积岩系的研究进展[J].岩石学报，2015,31(10):2816-2846.
[17]李壮，陈斌，刘经纬，等.辽东半岛南辽河群锆石U-Pb年代学及其地质意义[J].岩石学报，2015,31(6):1589-1605.
[18]王舫，刘福来，刘平华，等.南辽河群盖县组的重新厘定：来自辽南地区黄花甸—苏子沟一带变质砂岩碎屑锆石U-Pb年代学证据[J].岩石学报，2018,34(4):1219-1228, 1248-1253.
[19]聂飞，董国臣，莫宣学，等.滇西昌宁-孟连带三叠纪花岗岩地球化学、年代学及其意义[J].岩石学报，2012,28(5):1465-1476.
[20]Whalen J B,Currie K L,Chappell B W. A-type granites:geochemical characteristics,discrimination and petrogenesis[J].Contributions Mineralogy Petrology,1987,95:407-419.
[21]Chappell B,White A J R. I-and S-type granites in the Lachlan Fold Belt[J].Transactious of the Royal Society of Edinburgh.Earth Sciences,1992,83:1-26.
[22]Cornell D H,Schutte S S,Eglington R L. The Ongeluk Basaltic Andesite Formation in Grigualanel West South Africa Submarine Alteration in a 2222Ma Proterozoic Sea[J].Precambrain Research,1996,79(1/2):102-123.
[23]McKenzie D. Some Remarks on the Movement of Small Melt Fractions in the Mantle[J].Earth and Planetary Science Letters,1989,95(1):53-72.
[24]Taylor S R,McLennan S M. The geochemical evolution of the continental crust[J]. Reviews of Geophysics,1995,33(2):241-265.
[25]Barth M G,McDonough W F,Rudnick R L. Tracking the budget of Nb and Ta in the continental crust[J].Chemical Geology,2000,165:197-213.
[26]张秋生，杨振升，刘连登.辽东半岛早期地壳与矿床[M].北京:地质出版社，1988:218-450.
[27]李三忠，郝德峰，赵国春，等.丹东花岗岩的地球化学特征及其成因[J].岩石学报，2004,(6):116-122.
[28]Li S Z,Zhao G C,Sun M,et al. Deformation history of the Paleoproterozoic Liaohe assemblage in the Eastern block of the North China Craton[J].Journal of Asian Earth Sciences,2005,24(5):659-674.
[29]Li S Z,Zhao G C,Sun M,et al. Are the South and North Liaohe Groups of North China Craton different exotic terranes-Nd isotope constraints[J].Gondwana Research,2006,9(1):198-208.
[30]Li S Z,Zhao G C. SHRIMP U-Pb zircon geochronology of the Liaoji granitoids:Constraints on the evolution of the Paleoproterozoic Jiao-Liao-Ji belt in the Eastern Block of the North China Craton[J].Precambrian Research,2007,158(1):1-16.
[31]Luo Y,Sun M,Zhao G C,et al. LA-ICP-MS U-Pb zircon ages of the Liaohe Group in the Eastern Block of the North China Craton:Constraints on the evolution of the Jiao-Liao-Ji Belt[J].Precambrian Research,2004,134(3/4):349-371.
[32]Luo Y,Sun M,Zhao G C,et al. A comparison of U-Pb and Hf isotopic compositions of detrital zircons from the North and South Liaohe Groups:Constraints on the evolution of the Jiao-Liao-Ji Belt,North China Craton[J].Precambrian Research,2008,163(3/4):279-306.
[33]白瑾.中国前寒武纪地壳演化[M].北京：地质出版社，1993:47-89.
[34]Faure M,Lin W,MoniéP,et al. Palaeoproterozoic arc magmatism and collision in Liaodong Peninsula,NE China[J].Terra Nova,2004,16(2):75-80.
[35]Lu X P,Wu F Y,Guo J H,et al. Zircon U-Pb geochronological constraints on the Paleoproterozoic crustal evolution of the Eastern block in the North China Craton[J].Precambrian Research,2006,146(3/4):138-164.
[36]王惠初，陆松年，初航，等.辽阳河栏地区辽河群中变质基性熔岩的锆石U-Pb年龄与形成构造背景[J].吉林大学学报（地球科学版），2011,41(5):1322-1334,1361.
[37]Meng E,Liu F L,Liu P H,et al. Petrogenesis and tectonic significance of Paleoproterozoic meta-mafic rocks from central Liaodong Peninsula,Northeast China:Evidence from zircon U-Pb dating and in situ Lu-Hf isotopes,and whole-rock geochemistry[J].Precambrian Research,2014,247:92-109.
[38]Li Z, Chen B. Geochronology and geochemistry of the Paleoproterozoic meta-basalts from the Jiao-Liao-Ji Belt,North China Craton:Implications for petrogenesis and tectonic setting[J].Precambrian Research,2014,255:653-667.
[39]贺高品，叶慧文.辽东—吉南地区早元古代变质地体的组成及主要特征[J].长春科技大学学报，1998,(2):2-7,15.
[40]贺高品，叶慧文.辽东—吉南地区早元古代两种类型变质作用及其构造意义[J].岩石学报，1998,(2):25-35.
[41]Zhao G C,Cawood P A,Li S Z,et al. Amalgamation of the North China Craton:Key issues and discussion[J]. Precambrian Research,2012,222-223:55-76.
[42]Pearce J A,Harris N B W,Tindle A G. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks[J].Journal of Petrology,1984,25:956-983.
[43]郝德峰，李三忠，赵国春，等.辽吉地区古元古代花岗岩成因及对构造演化的制约[J].岩石学报，2004,(6):108-115.
[44]孙敏，张立飞，吴家弘.早元古代宽甸杂岩的成因：地球化学证据[J].地质学报，1996,(3):207-222.
[45]葛肖虹，刘俊来，任收麦，等.中国东部中—新生代大陆构造的形成与演化[J].中国地质，2014,41(1):19-38.
[46]毛景文，谢桂青，张作衡，等.中国北方中生代大规模成矿作用的期次及其地球动力学背景[J].岩石学报，2005,(1):171-190.
[47]杨宽，王建平，林进展，等.胶东半岛艾山岩体岩石地球化学特征及成因意义[J].地质与勘探，2012,48(4):693-703.
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