�Ժ���������������ɽ��Գ��ҽ������ʯ���ѧ�͵���ѧ�о�����ȷ�����γ�ʱ�������򼰹��챳������Գ����ʯ��������-�����ξ����ߵ��͵�����״���������ͽϸߵ�Th/U��ֵ��0.20~0.86������ʾ���ҽ�����LA-ICP-MS U-Pb������Ϊ��256±3��Ma��������ɽ��Գ����γ����������������ѧ������ʾ��Գ��Ҿ���ƶ�裬��þ�����������Ƶ�����������ϡ��Ԫ�أ�LREEs���ʹ�������ʯԪ�أ�Rb��Ba����������ϡ��Ԫ�أ�HREEs���͸߳�ǿԪ�أ�Nb��Ta��Zr��Hf��Ti�����𡣽������������ϣ���Ϊ��ɽ��Գ���Ϊ�������彻�����Ш�IJ�����γɿ�����Ŵ�����ĸ��������йأ���ʾ��ľ˹�ؿ������۵ؿ����������֮ǰ��δ��ײƴ�ϡ�

The authors analyzed zircon geochronological data and geochemical data of Zhushan metagabbro from Yilan, eastern Heilongjiang to determine their age, petrogenesis and tectonic setting. Zircons from metagabbro are euhedral-subhedral in shape with typical striation absorption features and high Th/U ratios (0.20~0.86), implying their magmatic origin. LA-ICP-MS zircon U-Pb dating shows that Zhushan metagabbro from Yilan formed during Late Permian with age of (256±3)Ma. The geochemical characteristics show that these metagabbros are low in silicon and high in magnesium, iron, aluminum and calcium. The rocks are enriched in LREEs and LILEs (Rb, Ba), and depleted in HREEs and HFSEs (Nb, Ta, Zr, Hf and Ti). Combined with the regional geological data, it is proposed that Zhushan metagabbro was derived from a mantle wedge that had been metasomatized by subducted slab-derived fluids. Its formation was probably related to the subduction of a paleo-oceanic plate, which implies that the collision between the Jiamusi Massif and the Songnen Massif may have not happened before Late Permian.

������Ȼ��ѧ�����ص���Ŀ��41330206�������ִ�ѧ��ѧ�����´�ҵѵ���ƻ���2015610789����������.

[1] ������.��ľ˹�м�ؿ�ǰ����͵����о�[J].��������ѧԺѧ��,1988,18(2):148-102. LIU Jing-lan. Precambrian geology of the Jiamusi block [J]. Journal of Changchun University of Earth Science, 1988, 18 (2): 148-102.
[2] ������.��ľ˹�м�ؿ����Ҵ����������ع��컷��dz��[J].����������,1991,2(1): 33-49. LIU Jing-lan. Analysis of characteristics of greenstone belt of Jiamusi median massif and its geotectonic setting [J]. Heilongjiang Geology, 1991, 2 (1): 33-49.
[3] ����,������,������,��.��ľ˹���ϵ���[M].����:���ֿ�ѧ����������,1992:1-224. CAO Xi, DANG Zeng-xin, ZHANG Xing-zhou, et al. Composite terrane of Jiamusi terrane [M]. Changchun: Jilin Science and Technology Press, 1992:1-224.
[4] �����.�й��������������ɵ��ʹ������������ʶ[J].��������, 1998,44(4): 339-348. LI Jin-yi. Some new ideas on tectonics of NE China and its neighboring areas[J]. Geological Review, 1998, 44 (4): 339-348.
[5] Wu F Y, Yang J H, Lo C H, et al. The Heilongjiang Group: a Jurassic accretionary complex in the Jiamusi Massif at the western Pacific margin of northeastern China[J]. Island Arc, 2007, 16: 156-172.
[6] Zhou J B, Wilde S A, Zhang X Z. The onset of Pacific margin accretion in NE China: evidence from the Heilongjiang high-pressure metamorphic belt[J]. Tectonophysics, 2009, 478: 230-246.
[7] Zhu C Y L, Zhao G C, Sun M, et al. Geochronology and geochemistry of the Yilan blue schists in the Heilongjiang complex, northeastern China and tectonic implications[J]. Lithos, 2015(216/217): 241-253.
[8] Sengör A M C, Natal'in B A, Burtman V S. Evolution of the Altaid tectonic collage and Paleozoic crustal growth in Eurasia[J]. Nature, 1993, 364: 299-307.
[9] Yu Q, Ge W C, Yang H, et al. Petrogenesis of Late Paleozoic volcanic rocks from the Daheshen Formation in central Jilin Province, NE China, and its tectonic implications: constraints from geochronology, geochemistry and Sr-Nd-Hf isotopes[J]. Lithos, 2014(192/195): 116-131.
[10] Xu W L, Ji W Q, Pei F P, et al. Triassic volcanism in eastern Heilongjiang and Jilin provinces, NE China: chronology, geochemistry, and tectonic implications[J]. Journal of Asian Earth Sciences, 2009, 34 (3): 392-402.
[11] Xu W L, Pei F P, Wang F, et al. Spatial-temporal relationships of Mesozoic volcanic rocks in NE China: constraints on tectonic overprinting and transformations between multiple tectonic regimes [J]. Journal of Asian Earth Sciences, 2013, 74: 167-193.
[12] Yu J J, Wang F, Xu W L, et al. Early Jurassic mafic magmatism in the Lesser Xing'an-Zhangguangcai Range, NE China, and its tectonic implications: constraints from zircon U-Pb chronology and geochemistry[J]. Lithos, 2012(142/143): 256-266.
[13] Tang J, Xu W L, Wang F, et al. Geochronology and geochemistry of Early-Middle Triassic magmatism in the Argun Massif, NE China: constraints on the tectonic evolution of Mongol-Okhotsk Ocean[J]. Lithos, 2013(184/187): 1-16.
[14] Tang J, Xu W L, Wang F, et al. Early Mesozoic southward subduction history of the Mongol-Okhotsk oceanic plate: evidence from geochronology and geochemistry of Early Mesozoic intrusive rocks in the Erguna Massif, NE China [J]. Gondwana Research, 2013, 31: 218-240.
[15] ����ʥ.��ɽȺ������ϵ�ز��¼�[J].�ز�ѧ��־,1992,16(4):304-311. JIANG Ji-sheng. Discovery of the khondalite series in the Mashan Group [J]. Journal of Stratigraphy, 1992, 16 (4): 304-311.
[16] ¬����,��ѧ��.�й�������ǰ����Ϳ�����ϵ[M].����:����������,1996:2-4. LU Liang-zhao, XU Xue-chun. Early Precambrian khondalite series in northern China[M]. Changchun: Changchun Press, 1996:2-4.
[17] Wilde S A, Dorsett-Bain H L, Liu J L. The identification of a Late Pan-African granulite facies event in northeastern China: SHRIMP U-Pb zircon dating of the Mashan Group at Liumao, Heilongjiang Province, China[C]//Proceedings of the 30th IGC: Precambrian Geology and Metamorphic Petrology, VSP International, 17. Amsterdam: Science Publishers, 1997:59-74.
[18] Wilde S A, Zhang X Z, Wu F Y. Extension of a newly-identified 500 Ma metamorphic terrain in Northeast China: further U-Pb SHRIMP dating of the Mashan complex, Heilongjiang Province, China [J]. Tectonophysics, 2000, 328: 115-130.
[19] �⸣Ԫ, Wilde S A, �����.��ľ˹�ؿ�Ƭ��״�����ҵ��ʯ����̽��U-Pb����[J].��ʯѧ��, 2001,17(4):43-52. WU Fu-yuan, Wilde S A, SUN De-you. Zircon SHRIMP ages of gneissic granites in Jiamusi Massif, northeastern China[J]. Acta Petrologica Sinica, 2001, 17 (4): 443-452.
[20] �⸣Ԫ,����.�����ǵ�����������Ҫ������������[J].�������,1999,18(2):1-13. WU Fu-yuan, CAO Lin. Some important problems of geology in northeastern Asia[J]. Global Geology, 1999, 18 (2): 1-13.
[21] Wu F Y, Sun D Y, Ge W C, et al. Geochronology of the Phanerozoic granitoids in northeastern China[J]. Journal of Asian Earth Science, 2011, 41: 1-30.
[22] Bi J H, Ge W C, Yang H, et al. Petrogenesis and tectonic implications of Early Paleozoic granitic magmatism in the Jiamusi Massif, NE China: geochronological, geochemical and Hf isotopic evidence[J]. Journal of Asian Earth Sciences, 2014, 96: 308-331.
[23] �ڽ齭,��ѩ��,���Ĵ�,��.��ľ˹�ؿ鶫��Ե�����������������ҽ���ϳ���:����ѧ�����ѧ�͵���ѧ֤��[J].��ʯѧ��,2013,29(9):2971-2986. YU Jie-jiang, HOU Xue-gang, GE Wen-chun, et al. Magma mixing genesis of the Early Permian Liulian pluton at the northeastern margin of the Jiamusi massif in NE China: evidences from petrography, geochronology and geochemistry [J]. Acta Petrologica Sinica, 2013, 29 (9): 2971-2986.
[24] ������ʡ���ʿ����. ������ʡ�������־[M]. ����:���ʳ�����, 1993: 8-585. Heilongjiang Bureau of Geology and Mineral Resources. Regional geology of Heilongjiang Province[M]. Beijing: Geological Publishing House, 1993: 8-585.
[25] Andersen T. Correction of common lead in U-Pb analyses that do not report ²⁰⁴Pb [J]. Chemical Geology, 2002, 192: 59-79.
[26] Winchester J A, Floyd P A. Geochemical magma type discrimination: application to altered and metamorphosed igneous rocks[J]. Earth Planet Science Letters, 1976, 45: 326-336.
[27] Miyashiro A. Volcanic rocks series in island arcs and active continental margins [J]. American Journal of Science, 1974: 274 (4):321-355.
[28] Cabanis B, Lecolle M. The La/10-Y/15-Nb/8 diagram-a tool for discrimination volcanic series and evidencing continental-crust magmatic mixtures and or contamination [J]. Comptes Rendus de Academie des Sciences II, 1989, 309: 2023-2029.
[29] Marjorite W. Igneous petrogenesis [M]. London: Un-win Hyman, 1989: 1191-225.
[30] Pearce J A, Norry M J. Petrogenetic implications of Ti, Zr, Y and Nb variations in volcanic rocks [J]. Contribution to Mineralogy and Petrology, 1979, 69(1): 33-47.
[31] Taylor S R, Rudnick R L, McLennan S M, et al. Rare element patterns in Archean high-grade metasediments and their tectonic significance[J]. Geochimica et Cosmochimica Acta, 1986, 50 (10): 2267-2279.
[32] Sun S S, McDonough W F. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[J]. Geological Society of Special Publication, 1989, 42: 313-345.
[33] Henderson P R. Rare earth element geochemistry[M]. Amsterdam: Elsevier, 1984:467-499.
[34] �ѽ���,������,��ұ,��.��ľ˹�ؿ鶫�������ͷ�ɽ����������ʯU-Pb���ѧ������ѧ���������������[J].�������,2015,34(4):903-911. PU Jian-bin, ZHANG Xing-zhou, GUO Ye, et al. Geological implications of Permian Fangshan granitic rocks in eastern Jiamusi Massif: evidences from U-Pb chronology and geochemistry[J]. Global Geology, 2015, 34 (4): 903-911.
[35] ����.������ʡ�����Ź����Ⱥ������:��ʯ��ϡ�ʱ�����乹������:˶ʿѧλ����[D].����:���ִ�ѧ, 2011. WANG Feng. The Xinxing Formation from Zhangguangcai Range Group in eastern Heilongjiang Province: rock association, geochronology and tectonic implications: master's degree thesis [D]. Changchun: Jilin University, 2011.
[36] ��ٻ,���Ĵ�,���,��.�Ź������������ɽ�ҵ��ʯU-Pb���ѧ������ѧ����[J].�������,2013,32(4):707-715. YU Qian, GE Wen-chun, YANG Hao, et al. Zircon U-Pb chronology and geochemical characteristics of volcanic rocks from Wudaoling Formation in Zhangguangcai Range[J]. Global Geology, 2013, 32 (4): 707-715.
[37] ����,��֧��,�³��,��.��������־һ���¹̰������ɽ��м�� LA-ICP-MS�ʯ U-Pb�������ʯ��ѧ����[J].�������,2016,35(1):28-39. SUN Xiao, GUO Zhi-tao, DOU Lu-wen, et al. LA-ICP-MS zircon U-Pb dating and geochemical characteristics of volcano clastic rocks in Gu'antun Formation of Yimianpo of Shangzhi, Heilongjiang Province [J]. Global Geology, 2016, 35(1): 28-39.
[38] Frey F A, Prinz M U. Ultramafic inclusions from San Carlos, Arizona: petrologic and geochemical data bearing on their petrogenesis[J]. Earth and Planetary Science Letters, 1978, 38 (1): 129-176.
[39] Ji W Q, Xu W L, Yang D B, et al. Chronology and geochemistry of volcanic rocks in the Cretaceous Suifenhe Formation in eastern Heilongjiang, China[J]. Acta Geologica Sinica, 2007, 81 (2): 266-277.
[40] Ionov D A, Gregoire M, Prikhodko V S. Feldspar-Ti-oxide metasomatism in off-cratonic continental and oceanic upper mantle[J]. Earth and Planetary Science Letters, 1999, 165 (1): 37-44.
[41] Jahn B M, Wu F Y, Lo C H, 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[J]. Chemical Geology, 1999, 157: 119-146.
[42] Gill J B. Orogenic andesites and plate tectonics[M]. New York: Springer Verlag, 1981:385.
[43] Laflèche M R, Camire G, Jenner G A. Geochemistry of post-Acadian, Carboniferous continental intraplate basalts from the Maritimes Basin, Magdalen islands, Quebec, Canada [J]. Chemical Geology, 1998, 148: 115-136.
[44] Kepezhinskas P, Mcdemott F P, Defant M J, et al. Trace element and Sr-Nd-Pb isotopic constraints on a three-component model of Kamchatka arc petrogenesis[J]. Geochimica et Cosmochimica Acta, 1997, 61 (3): 577-600.
[45] Li J Y. Permian geodynamic setting of Northeast China and adjacent regions: closure of the Pale-Asian Ocean and subduction of the Paleo-Pacific Plate[J]. Journal of Asian Earth Sciences, 2006, 26: 207-224.
[46] �α�,ţ����,�����,��.ĵ����—���������������ͬλ�����ѧ�о�[J].��ʯ����ѧ־,1994,13(4):204-213. SONG Biao, NIU Bao-gui, LI Jin-yi, et al. Isotope geochronology of granitoids in Mudanjiang-Jixi area[J]. Acta Petrologica et Mineralogica, 1994, 13 (4): 204-213.
[47] Pei F P, Xu W L, Yang D B, et al. Zircon U-Pb geochronology of basement metamorphic rocks in the Songliao Basin[J]. Chinese Science Bulletin, 2007, 52 (7): 942-948.
[48] ��ӳ��,�ζ���,������,��.������ʡ��������¡�����������ҵ��ʯU-Pb���꼰���������[J]. ���ִ�ѧѧ��:�����ѧ��,2008,38(4):631-638. HUANG Ying-cong, REN Dong-hui, ZHANG Xing-zhou, et al. Zircon U-Pb dating of granite in Huanan uplift eastern part of Heilongjiang Province and its geological significance [J]. Journal of Jilin University: Earth Science Edition, 2008, 38 (4): 631-638.
[49] Meng E, Xu W L, Pei F P, et al. Permian bimodal volcanism in the Zhangguangcai Range of eastern Heilongjiang Province, NE China: zircon U-Pb-Hf isotopes and geochemical evidence[J]. Journal of Asian Earth Sciences, 2011, 41: 119-132.
[50] ����,������,�Ծ���,��.�������������Ͱ��ҵ���ʯ����ѧ������������о�[J].��ʯѧ��,2005,21(3):947-953. LIU Shen, HU Rui-zhong, ZHAO Jun-hong, et al. Geochemical characteristics and petrogenetic investigation of the Late Mesozoic lamprophyres of Jiaobei, Shandong Province[J]. Acta Petrologica Sinica, 2005, 21 (3): 947-953.
[51] Meschede M. A method of discriminating between different types of mid-ocean ridge basalts and continental tholeiites with the Nb-Zr-Y diagram[J]. Chemical Geology, 1986, 56: 207-218.
[52] Condie K C, Crow C. Early Precambrian within-plate basalts from the Kaapvaal Craton in Southern-Africa: a case for crustally contaminated komatiites[J]. The Journal of Geology, 1990, 98 (1): 100-107.
[53] Pearce J A. Role of the sub-continental lithosphere in magma genesis at active continental margins[C]//Hawkesworth C J, Norry M J. Continental Basalts and Mantle Xenoliths. Nantwich: Shiva Publications, 1983:230-249.