铜陵地区中生代中酸性侵入岩的地球化学特征及其成矿-地球动力学意义
The geochemical characteristics of Mesozoic intermediate-acid intrusives of the Tongling area and its metallogenesis-geodynamic implications
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摘要: 本文对铜陵地区晚侏罗世-早白垩世高钾钙碱性中酸性侵入岩进行了研究,发现该类岩体具有埃达克岩的地球化学特征,具体表现为:SiO2≥56％,Al2O3含量高(>15％),Na2O/K2O>1,亏损HREE,(La/Yb)N>12,负Eu异常不明显(Eu*/Eu=0.71-0.96),Sr含量高(>750μg/g),Sr/Y比值高(>38)。但是,由于岩石的K2O含量较高、εNd(t)较低和ISr值较高,又不同于典型的与板块俯冲有关的埃达克岩,而与中国东部中生代的C型埃达克岩比较类似,暗示铜陵地区的高钾钙碱性岩可能是加厚的下地壳底部基性岩部分熔融的产物。本文主要依据铜陵埃达克质岩的HREE特征,将其分为三类:第一类岩体为HREE平坦型,Yb含量较高(>1.8μg/g);第二类为HREE平坦型,Yb<1.8μg/g,(Ho/Yb)N≈1;第三类岩体HREE亏损,Yb<1.8μg/g,(Ho/Yb)N<1.2。上述三类岩石地球化学性质上的差异不太可能是分离结晶作用或地壳混染的 结果,而可能是由于幔源岩浆与下地壳物质混合的程度不同引起源区成分不同形成的。铜陵地区及中国东部埃达克质岩石可能代表了中国东部中生代时的地壳增生和加厚过程。铜陵埃达克岩主要是古老下地壳和底侵玄武岩不同比例混合部分熔融形成的,在岩浆演化过程中可能还不同程度地叠加了分离结晶作用和岩浆混合作用的影响。铜陵埃达克岩具岛弧特征,但并不表明其
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Key words:
- Intermediate-acid intrusive rocks /
- Geochemistry /
- Adakite /
- Tongling /
- Mesozoic /
- Metallogenesis
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[1] ［1］Alberto E, Douce P. 1995. Experimental generation of hybrid silicic melts by reaction of highAl basalt with metamorphic rocks. J.Geophys. Res, 100(B8): 15623-15639
[2] ［2］Atherton M P, Petford N. 1993. Generation of sodium-rich magmas from newly underplated basaltic crust. Nature, 362: 144 - 146
[3] ［3］Bao Y G, Bai Z M, Ge S W, Liu C. 1995. Volcanic Geology and Volcanic Rocks of Yanshanian Period in Beijing. Beijing: Geological Publishing House, 1 - 164 ( in Chinese)
[4] ［4］Barbarin B. 1999. A review of the relationships between granitoid types,their origins and their geodynamic environments. Lithos, 46: 605 -625
[5] ［5］Castillo P R. 2002. The origin of some of the adakite-like and Nbenriched lavas in southern Philippines. Acta Petrologica Sinica, 18:143 - 151
[6] ［6］Chang Yinfo, Liu Xiangpei, Wu Yanchang. 1991. Copper-iron oreforming belt in the lower reaches of Yangtze River. Beijing:Geological Publishing House, 1 -379. (in Chinese)
[7] ［7］Chen B, Zhai M G, Shao J A. 2003. Petrogenesis and significance of the Mesozoic North Taihang complex: Major and trace element evidence.Science in China, 46:941 -953 (in press)
[8] ［8］Chen J F, Yan J, Xie Z, Xu X, Xing F. 2001. Nd and Sr isotopic compositions of igneous rocks from the lower Yangtze region in eastern China: constraints on sources. Phys. Gem. Earth (A), 26:719 -731
[9] ［9］Chu G Z, Huang X C. 1993. A study on metallogenic patterns of mineral deposit in Tongling district, Anhui Province. Geology and Prospecting, 29(1): 1 -6 (in Chinese)
[10] ［10］Dai Z X. 1996. Supergiany ore deposits (areas) in the world. In:Chinese Institute of Geology and Mineral Resources Information.1996. Geological Sciences and Mineral Resources for the 21st Century. Beijing: Geological Publishing House, 34 -42 (in Chinese)
[11] ［11］Davis G A, Qian X, Zheng Y, Yu H, Wang C, Tong H M, Gehrels G E, Shafiquallah M, Fryxell J E. 1996. Mesozoic deformation and plutonism in the Yunmeng Shan: A Chinese metamorphic core complex north of Beijing, China. In: Yin A, and Harrison T M.(eds.), The Tectonics Evolution of Asia. Cambridge University Press, 253 -280
[12] ［12］Davis G A, Zheng Y D, Wang C, Darby B J, Zhang C H. 2001. Mesozoic tectonic evolution of the Yanshan fold and thrust belt, with emphasis on Hebei and Liaoning provinces, northern China. In:Hendrix M S, Davis G A. ( eds. ) Paleozoic and Mesozoic Tectonics of Central Asia: From Continental Assembly to Intracontinental Deformation. Boulder, Colorado: Geological Society of America,171 - 197
[13] ［13］Defant M J, Drummond M S. 1990. Derivation of some modem arc magmas by melting of young subducted lithosphere. Nature, 347:662 - 665
[14] ［14］Defant M J. 2002. Reply for comment by R. Conner on the "Evidence suggests slab melting in arc magmas" by M. Defant and P.Kepezhinskas (EOS, 2001, 82: 65, 68 -69). EOS, 66:256 -257
[15] ［15］Defant M J, Xu J F, Kepezhinskas P, Wang Q, Zhang Q and Xiao L.2002. Adakites: some variations on a theme. Acta Petrologica Sinica, 18:129 - 142
[16] ［16］Deng J F, Dai S Q, Zhao H L, Du J G. 2002. Recognition of magmaticfluid-metallogenic systems and subsystems in Tongling Cu-Au (Ag)ore-forming area. Mineral Deposits, 21: 317 - 322. (in Chinese with English abstract)
[17] ［17］Deng J F, Liu H X, Zhao H L. 1996. Yanshanian igneous rocks and orogeny model in Yanshan-Liaoning area. Geoscience, 10:137-148( in Chinese with English abstract)
[18] ［18］Deng J F, Zhao G C, Zhao H L, Luo Z H, Dai S Q, Li K M. 2000. Yanshanian igneous petrotectonic assemblage and orogenic-deep processes in East China. Geological Review, 46:41 -48. (in Chinese with English abstract)
[19] ［19］Deng Jinfu, Ye Delong, Zhao Hailing, Tang Deping et al. 1992. Volcanism, deep internal processes and basin formation in the Lower Reaches of the Yangtze River. Wuhan: Press of China University of Geosciences, 1 -184 (in Chinese with English abstract)
[20] ［20］Di Y J, Zhao H L, Zhang Y Q, Zhao J H, Yang L. 2003. Petrographic evidences for magma mixing in the granitoids from Tongling area,Anhui Province. Beijing Geology, 15: 12 - 17 (in Chinese with English abstract)
[21] ［21］Du Y S, Li X J. 1997. Enclaves in the typical mining districts of Tongling, Anhui and their implication to the process of magmatismmetallogeny. Geological Journal of China Universities, 3: 171 - 180(in Chinese with English abstract)
[22] ［22］Faure M, Sun Y, Sbu L, Monie P, Charvet J. 1996. Extensional tectonics within a subduction-type orogen: the case study of the Wugongshan Dome ( Jiangxi province, southeastern China ).Tectonophysics, 263: 77-106
[23] ［23］Forster H J, Tischendorf G, Trumbull R B. 1997. An evaluation of the Rb vs. ( Y + Nb) discrimination diagram to infer tectonic setting of silicic igneous rocks. Lithos, 40:261 -293
[24] ［24］Fu H F. 1989. High-pressure melting of tholeiite from Xigaze, Tibet-an experimental study. Geochimica, 17:20 -26 (in Chinese with English abstract)
[25] ［25］Gao S, Qiu Y M, Ling W L, McNaughton N J, Groves D I. 2001. SHRIMP single zircon U-Pb dating of the Kongling high-grade metamorphic terrain: Evidence for ＞ 3.2 Ga old continental crust in the Yangtze craton. Science in China ( series D), 44: 326 - 335
[26] ［26］Ge X Y, Li X H, Chen Z G, Li W P. 2002. Geochemistry and petrogenesis of Jurassic high Sr/low Y granitoids in eastern China:Constraints on crustal thickness. Chinese Science Bulletin, 47:961-968
[27] ［27］Green T H. 1994. Experimental studies of trace-element partitioning applicable to igneous petrogenesis Sedona 16 years later. Chemical Geology, 117:1-36
[28] ［28］Jabn B M, Zhou X H, Li J L. 1990. Formation and tectonic evolution of southeastern China and Taiwan: Isotopic and geochemical constraints. Tectonophys, 183: 145 - 160
[29] ［29］Lapierre H, Jabn B M, Charvet J, et al. 1997. Mesozoic felsic arc magmatism and continental olivine tholeiites in Zhejiang Province and their relationship with the tectonic activity in southeastern China.Tectonophys. , 274:321 -338
[30] ［30］Li J Y. 1998. Some new ideas on tectonics of NE China and its neighboring areas. Geological Review, 44:339 - 347 (in Chinese with English abstract)
[31] ［31］Li W X, Zhou X M. 1999. Late Mesozoic subduction zone of Southeastern China. Geological Journal of China Universities, 5:164 -168( in Chinese with English abstract)
[32] ［32］Li W X, Zhou X M. 2000. Geochemical constraints on the petrogenesis of late Mesozoic igneous rocks from the coastal area of Zhejiang and Fujian provinces. Progress in Natural Science, 10: 630- 641
[33] ［33］Li X H. 2000. Cretaceous magmatism and lithospheric extension in Southeast China. Journal of Asian Earth Sciences, 18:293 -305
[34] ［34］Liu H, Qiu J S, Lo C H, Xu X S, Li W L, Wang D Z. 2002. Petrogenesis of the Mesozoic potash-rich volcanic rocks in the Luzong basin, Anhui Province: Geochemical constraints. Geochimica, 31:129 -140 (in Chinese with English abstract)
[35] ［35］Liu M L, Wang Z Q, Peng S L, Yang Q Z, Shao Y J. 2001. Application of comprehensive informationism prediction for ore prospecting in deeper and outer of mines with critical reserves: an example from the Fenghuangshan Copper Mine, Tongling. Scientia Geologica Sjnica,37: 445 -452. ( in Chinese with English abstract)
[36] ［36］Lu Z G, Tao K Y, Xie J Y, Xie D K, Wang W B, Chen H N et al.1997. Volcanic Geology and Mineral Resources of Southeast China Continent. Beijing: Geological Publishing House, 1 -431 (in Chinese with English abstract)
[37] ［37］Ma C, Ehlers C, Xu C, et al. 2000. The roots of the Dabieshan ultrahigh-pressure metamorphic terrane: constraints from geochemistry and Nd-Sr isotope systematics. Precambrian Research,102: 279
[38] ［38］Ma C Q, Yang K G, Tang Z H. 1994. Magmatic dynamics of granitoid rocks: Theory, method and examples from granitoid rocks in east Hubei Province. Wuhan: Press of China University of Geosciences,1-249. (in Chinese)
[39] ［39］Maniar P D, Piccoli P M. 1989. Tectonic discrimination of granitoids.Geol. Soc. Am. Bull., 101:635-643
[40] ［40］Mao J R, Su Y X, Chen S Y. 1990. Intermediate-acid intrusions and mineralization in the middle and lower reach of Yangtze River.Beijing: Geological Publishing House, 1 - 191. (in Chinese with English abstract)
[41] ［41］Mao J W, Hua R M, Li X B. 1999. A preliminary study of large scale metallogenesis and large clustewrs of mineral deposits. Mineral Deposits, 18:291 -299. (in Chinese with English abstract)
[42] ［42］Martin H. 1999. Adakitic magmas: modern analogues of Archean granitoids. Lithos, 46: 411 - 429
[43] ［43］Menzies M, Xu Y. 1998. Geodynamics of the North China Craton. in:Flower M, Chung S L, Lo C H, Lee T Y. ( eds. ) Mantle Dynamics and Plate Interaction in East Asia. Washington, D C: Am.Geophys. Union Geodynamic, 27: 155～165
[44] ［44］Muir R J, Weaver S D, Bradshaw J D. et al. 1995. Geochemistry of the Cretaceous Separation Plint Batholith, New Zealand: granitoid magmas formed by melting of mafic lithosphere. J. Geol. Soc.Lond., 152: 689 - 701
[45] ［45］Oyarzun R, Marquez A, Lillo J, Lopez I, Rivera S. 2001. Giant versus small porphyry copper deposits of Cenozoic age in northern Chile:adakitic versus normal calc-alkaline magmatism. Mineralium Deposita, 36: 794 -798
[46] ［46］Peacock S M, Rushmer T, Thompson A B. 1994. Partial melting of subducting oceanic crust. Earth Planet. Sci. Lett. , 121: 227 -244
[47] ［47］Pearce J A, Harris B W, Tindle A G. Trace element discrimination diagrams for the tectonic interpretations of granitic rocks. J. Petrol. ,1984, 25: 956 - 983
[48] ［48］Pitcher W S. 1983. Granite type and tectonic environment. In: Hsu K(ed.) Mountain Building Processes. Academic Press, London, 19-40
[49] ［49］Qian Q, Chung S L, Lee T Y, Wen D J. 2002. Geochemical characteristics and petrogenesis of the Badaling high Ba-Sr granitoids: a comparison of igneous rocks from North China and the Dabie-Sulu Orogen. Acta Petrologica Sinica, 18:275 - 292 (in Chinese with English abstract)
[50] ［50］Rapp R P, Watson E B. 1995. Dehydration melting of metabasalt at 8-32 Kbar :implication for continental growth and crust-mantle recycling. J. Petrol. , 36:891 -931
[51] ［51］Rapp R P, Xiao L, Shimizu N. 2002. Experimental constraints on the origin of potassium-rich adakites in eastern China. Acta Petrologica Sinica, 18: 293 -302
[52] ［52］Rapp R P. 1995. Amphibole-out physe boundary in partially melted metabasalt, its control over liquid fraction and composition and source permeability. J. Geophys. Res., 100(B8): 15601-15610
[53] ［53］Roberts M P, Clemens J D. 1993. Origin of high-potassium, calcalkaline, Ⅰ-type granitoids. Geology, 21:825-828
[54] ［54］Sajona FG, Maury RC. 1998. Association of adakites with gold and copper mineralization in the Philippines. CR ACAD SCⅠⅡ A, 326(1): 27-34
[55] ［55］Shi J F, Wu C B. 2000. A new exploration strategy for giant depositsinformation exploration. Mineral Deposits, 19: 88 - 95 (in Chinese with English abstract)
[56] ［56］Tang Yongcheng, Wu Yanchang, Chu Guozheng, Xing Fengming, Wang Yongmin, Cao Fenyang, Chang Yinfo. 1998. Geology of coppergold polymetallic deposits in the Along-Changjiang Area of Anhui Province. Beijing: Geological Publishing House, 1 -351. (in Chinese with English summary)
[57] ［57］Tao Kuiyuan. 1988. The basic characteristics of the Mesozoic volcanism in the southeast coastal area of China. Bulletin of Nanjing Institute of Geology and Mineral Resources, 9:12 -30. (in Chinese with English abstract)
[58] ［58］Taylor S R, Mclenman S M. 1985. The Continental Crust: Its Composition and Evolution. New York: Blackwell Sci. Publ
[59] ［59］Thieblemont D, Stein G, Lescuyer J-L. 1997. Gisements epithermaux et porphyriques: la connexion adakite. Earth Planet. Sci. , 325:103-109
[60] ［60］Wang D Z, Ren Q J, Chen K R. 1996. Charaterisitics of volcanic rocks in the shoshonite province, eastern China and their metallogenesis.Acta Geologica Sinica, 70:23 -34. (in Chinese with English abstract)
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