An Isotopic (Sr, Nd and Pb) Tracer Study on the Xiaoxinancha Gold‐rich Copper Deposit in Yanbian, China: Implication for the Geodynamic Model of Diagenesis and Metallogenesis

An isotopic study was systemically carried out on the granitic complex, diorite‐porphyrite, ores and ore minerals of the 103 Ma Xiaoxinancha gold‐rich copper deposit in Jilin province to determine the geodynamic model of diagenesis and metallogenesis. Results show that the initial Nd and Sr isotopic compositions of the granitic complex are in the range of 0.70425–0.70505 for (87Sr/86Sr)i, 0.51243–0.51264 for INd, and –1.31 to + 2.64 for εNd(t); those of the diorite‐porphyrite are in the range from 0.70438–0.70448 for (87Sr/86Sr)i, 0.51259–0.51261 for INd, and + 1.56 to + 2.09 for εNd(t). For ores and sulfides, the (87Sr/86Sr)i, INd, and εNd(t) values are in the range from 0.70440–0.70805, 0.51259–0.51279 and +1.72 to +5.56, respectively. The Pb isotopic ratios of the granitic complex range from 18.2992–18.6636 for 206Pb/204Pb, from 15.5343–15.5660 for 207Pb/204Pb, and from 38.1640–38.5657 for 208Pb/204pb For diorite‐porphyrite, the isotopic ratios of 206Pb/204Pb, 207Pb/204Pb and 208Pb/204b are 18.3919, 15.5794 and 38.3566, respectively, whereas those of the ores and ore sulfides vary from 18.2275–18.3770 for 206Pb/204Pb, from 15.5555–15.5934 for 207Pb/204Pb and from 38.1318–38.3131 for 208Pb/204Pb. The results indicate that the mineralization was correlated to the formation and evolution of the granitic complex and the diorite‐porphyrite. Combining with the reported data in petrologic characteristics, elemental geochemistry and chronology, conclusions can be drawn that the geodynamic settings of diagenesis and metallogenesis of this deposit were consistent with the subduction of the Izanagi oceanic plate during the Early Cretaceous. The diorite‐porphyrite was formed by the emplacement of the adakitic magma triggered by partial melting of the enriched mantle, which originated from the derivative continental lithospheric mantle metasomatized by dehydration fluids from the subducting oceanic crust. The granitic complex was produced by fractional crystallization of the mixture between the adakitic magma and the high‐K calc‐alkaline acidic magma, which were generated by the remelting of the lower crust in the course of intraplate upwelling of the adakitic magma. The ore‐bearing fluid reservoir convened in a late stage of the evolution of the mixed magma chamber.

[1]  F. Sun,et al.  Geochemistry and Genesis of the Late Jurassic Granitoids at Northern Great Hinggan Range: Implications for Exploration , 2010 .

[2]  Zhiming Sun,et al.  Crustal Composition of China Continent Constrained from Heat Flow Data and Helium Isotope Ratio of Underground Fluid , 2010 .

[3]  Liu Jianming,et al.  Mantle Branch Structure in the South‐Central Segment of the Da Hinggan Mts., Inner Mongolia and Its Ore‐controlling Role , 2009 .

[4]  M. Rahgoshay,et al.  Petrogenesis of Volcanic Rocks in the Khabr‐Marvast Tectonized Ophiolite: Evidence for Subduction Processes in the South‐Western Margin of Central Iranian Microcontinent , 2009 .

[5]  Chen Yan.  Significant achievements and open issues in study of orogenesis and metallogenesis surrounding the North China continent , 2009 .

[6]  K. Nagao,et al.  Ore-forming mechanism for the Xiaoxinancha Au-rich Cu deposit in Yanbian, Jilin Province, China: Evidence from noble gas isotope geochemistry of fluid inclusions in minerals , 2008 .

[7]  Sun Jing.  SHRIMP U-Pb dating of zircons from Late Yanshanian granitic complex in Xiaoxinancha gold-rich copper orefield of Yanbian and its geological implications , 2008 .

[8]  Chen Lei.  Characteristics and Implications of Daughter Minerals in Fluid Inclusions of Xiaoxinancha Gold-Rich Copper Deposit , 2008 .

[9]  Li Jin.  Basic characteristics of gold-rich porphyry copper deposits and their ore sources and evolving processes of high oxidation magma and ore-forming fluid. , 2006 .

[10]  Wu Zong-xu.  Discussion on the lithospheric thinning of the North China craton: delamination? or thermal erosion and chemical metasomatism? , 2006 .

[11]  Pei Fu-ping,et al.  The discovery of deep xenolith and xenocryst in Mesozoic volcanic rock in Mingyuegou Basin of Yanbian area and their mineralogical chemistry , 2005 .

[12]  Niu Zhi-jun.  Identification of the adakitic rock association in Chibzhang Co area, northern Tibet, and its significance , 2005 .

[13]  F. Pirajno,et al.  Isotope geochemistry of the Tieluping silver-lead deposit, Henan, China: A case study of orogenic silver-dominated deposits and related tectonic setting , 2004 .

[14]  Qu Xiaoming.  Source Compositions and Crustal Contaminations of AdakiticOre-bearing Porphyries in the Gangdise Copper Belt:Nd, Sr, Pb and O Isotope Constraints , 2004 .

[15]  J. Richards.  Tectono-Magmatic Precursors for Porphyry Cu-(Mo-Au) Deposit Formation , 2003 .

[16]  Bin Chen,et al.  Sr–Nd isotopic characteristics of the Mesozoic magmatism in the Taihang–Yanshan orogen, North China craton, and implications for Archaean lithosphere thinning , 2003, Journal of the Geological Society.

[17]  Q. Zhang,et al.  Adakites from continental collision zones: Melting of thickened lower crust beneath southern Tibet , 2003 .

[18]  K. Uto,et al.  Geochemistry of Cenozoic basalts in the Fukuoka district (northern Kyushu, Japan): implications for asthenosphere and lithospheric mantle interaction , 2003 .

[19]  Bin Chen,et al.  Geochemistry of late Mesozoic lamprophyre dykes from the Taihang Mountains, north China, and implications for the sub-continental lithospheric mantle , 2003, Geological Magazine.

[20]  X. Ji.  TRACING THE THICKENING PROCESS OF CONTINENTAL CRUST THROUGH STUDYING ADAKITIC ROCKS:EVIDENCE FROM VOLCANIC ROCKS IN THE NORTH TIBET , 2003 .

[21]  Yigang Xu.  Evidence for crustal components in the mantle and constraints on crustal recycling mechanisms: pyroxenite xenoliths from Hannuoba, North China , 2002 .

[22]  G. Wörner,et al.  Sources and Fluids in the Mantle Wedge below Kamchatka, Evidence from Across-arc Geochemical Variation , 2001 .

[23]  Y. Jin,et al.  The characteristics and tectonic-metallogenic significances of the adakites in Yanshan period from eastern China. , 2001 .

[24]  J. Baker,et al.  On and Off the North China Craton: Where is the Archaean Keel? , 2000 .

[25]  J. De la Rosa,et al.  Origin of peraluminous granites and granodiorites, Iberian massif, Spain: an experimental test of granite petrogenesis , 1999 .

[26]  C. Lo,et al.  Crust–mantle interaction induced by deep subduction of the continental crust: geochemical and Sr–Nd isotopic evidence from post-collisional mafic–ultramafic intrusions of the northern Dabie complex, central China , 1999 .

[27]  R. Sillitoe,et al.  Characteristics and controls of the largest porphyry copper‐gold and epithermal gold deposits in the circum‐Pacific region , 1997 .

[28]  R. Rudnick,et al.  Nature and composition of the continental crust: A lower crustal perspective , 1995 .

[29]  M. Brown,et al.  The generation, segregation, ascent and emplacement of granite magma: the migmatite-to-crustally-derived granite connection in thickened orogens , 1994 .

[30]  S. Kay,et al.  Evidence in Cerro Pampa Volcanic Rocks for Slab-Melting Prior to Ridge-Trench Collision in Southern South America , 1993, The Journal of Geology.

[31]  N. Petford,et al.  Generation of sodium-rich magmas from newly underplated basaltic crust , 1993, Nature.

[32]  J. C. Allen,et al.  Magma sources for Mesozoic anorogenic granites of the White Mountain magma series, New England, USA , 1991 .

[33]  S. Hart,et al.  Heterogeneous mantle domains: signatures, genesis and mixing chronologies , 1988 .

[34]  S. Hart,et al.  Lead-isotopic signatures of porphyry copper deposits in oceanic and continental settings, Colombian Andes , 1984 .

[35]  M. Norry,et al.  Possible origin of K-rich volcanic rocks from Virunga, East Africa, by metasomatism of continental crustal material: Pb, Nd and Sr isotopic evidence , 1983 .

[36]  B. Doe,et al.  Plumbotectonics-the model , 1981 .

[37]  G. Wasserburg,et al.  Sm-Nd age of the Stillwater complex and the mantle evolution curve for neodymium , 1979 .

[38]  P. Hamilton,et al.  Geochemical and Cosmochemical Applications of Nd Isotope Analysis , 1979 .

[39]  R. Kay.  Aleutian magnesian andesites: Melts from subducted Pacific ocean crust , 1978 .

[40]  B. Doe,et al.  The Application of Lead Isotopes to the Problems of Ore Genesis and Ore Prospect Evaluation: A Review , 1974 .

[41]  R. Sillitoe.  A Plate Tectonic Model for the Origin of Porphyry Copper Deposits , 1972 .