宁芜火山岩的地球化学特征及其意义
Geochemical characteristics of volcanic rocks from Ningwu area, and itssignificance
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摘要: 宁芜早白垩世火山岩由中基性成分组成，与碱性玄武岩比较，火山岩贫Ti,Fe，富K和LREE，Na2O/K2O近似等于1，在SiO2-K2O图中龙王山组的全部和大王山组的大部落入橄榄玄粗岩区域，属于橄榄玄粗岩系列，为富集LILE和水的地幔部分熔融的产物。宁芜火山岩产于板内环境，富钾质岩浆的形成可能与软流圈地幔上涌和岩石圈的伸展－减薄或裂谷作用有关。宁芜火山岩富集大离子亲石元素，亏损高场强元素，Ti,Nb(Ta)具负异常。宁芜火山岩底部的龙王山组和主体大王山组具有不同的地球化学特征：与大王山组相比，前者更富Rb,Ba,K，而相对贫LREE（La,Ce,Nd),Eu,Sr,Isr较高，εNd(t)较低。由于龙王山组层位低，大王山组层位高，不可能解释为分离结晶作用的结果，而只能说明在火山岩喷发的早期阶段（龙王山组），岩浆穿过陆壳上升过程中与围岩发生过混染作用，从围岩中带入较多的K、Rb,Ba等大离子亲石元素，从而使得Isr较高和εNd(t)较低。龙王山组SiO2-K2O不具相关性也说明陆壳混染的影响。至宁芜火山岩喷发的极盛时期（大王山组），岩浆与围岩的混染程度降低，Isr和Nd(t)值更接近岩浆的初始组成。据了解，在长江中下游地区有许多晚中生代的埃达克质岩出露，埃达克质岩来自加厚的陆壳底部，需要很高的温度才能使下地壳基性岩发生部分熔融。宁芜一带火山岩的大规模喷出，表明在早白垩世初期该区地幔处于十分活跃的状态，可能有大量橄榄玄粗质岩浆底侵到下地壳底部，烘烤下地壳使之熔融形成埃达克质熔浆。
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Key words:
- Nanjing-Wuhu area /
- Early Cretaceous /
- Volcanic rocks /
- Shoshonitic series /
- Adakite-like rocks /
- Geochemistry
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[1] ［1］Bacon C R. 1990. Calc-alkaline,shoshonite and primitive tholeiitic lavas from monogenetic volcanics near Crater Lake,Oregon. J.Petrol., 31:135-166
[2] ［2］Beccaluva L, Girolamo P D, Serri G. 1991. Petrogenesis and tectonic settings of theRoman volcanic province, Italy. Lithos,26:191-221
[3] ［3］Chen J F, Foland K A, Zhou T X. 1985. Mesozoic granitoids of the Yangtze fold belt:Isotopic constraints on the magma sources.In: Wu L R et al. (eds.). The crust-thesignificance of granite gneisses in the Lithosphere. Theophrastus, Athens, 217- 237
[4] ［4］Chen J F, Jahn B M. 1998. Crustal evolution of southeastern China:Nd and Srisotopic evidence. Tectonophy. , 284: 101-133
[5] ［5］Chen J F, Zhou T X, Li X M et al. 1993. Sr and Nd isotopic constraints on sourceregions of the intermediate and acidic intrusions from southern Anhui province.Geochemistry, 3:261-268 (in Chinese with English abstract)
[6] ［6］Defant M J, Drummond M S. 1990. Derivation of some modern arc magmas by melting ofyoung subduction Lithosphere. Nature,347:662-665
[7] ［7］Foley S F, Peccerillo A. 1992. Potassic and ultrapotassic magmas and their origin.Lithos, 28:181～185
[8] ［8］Guo F, Fan WM, Wang YJ and Lin G. 2001. Petrogenesis of the late Mesozoic bimodalvolcanic rocks in the southern Da Hinggan Mrs. , China. Acta Petrologica Sinica, 17:161-168(in Chinese with English abstract)
[9] ［9］Joplin G A. 1968. The shoshonite association: a review. J. Geol.Soc. Aust. ,15:275-294
[10] ［10］Li Xian-hua, McCulloch M T. 1998. Geochemical characteristics of Cretaceous maficdikes from northern Guangdong, SE China:ge, origin and tectonic significance. In: Flower MF J et al.(eds.). Mantle Dynamics and Plate Interactions in East Asia.Am. Geophys. Union.Washington D. C. 405-419
[11] ［11］Li Xianhua, Zhou Hanwen, Liu Ying et al. 2001. Mesozoic shoshonitic intrusives inthe Yangchun Basin, western Guangdong, and their tectonic significance: II. Trace elementsand Sr-Nd isotopes. Geochimica, 30:57-65 (in Chinese with English abstract)
[12] ［12］Ma CQ, Yang KG, Tang ZH. 1994. Magma-dynamics of granitoids - theory, method and acase study of the eastern Hubei granitoids. Wuhan: Press of China University ofGeosciences.(in Chinese)
[13] ［13］Mao J R, Su Y X, Chen S Y. 1990. Felsic intrusions and mineralization in themiddle and lower paer of Yangtze River.Beijing: Geological Phublishing House, 1- 191. (inChinese with English abstract)
[14] ［14］Meen J K. 1987. Formation of shoshonites from calc-alkaline basalt magmas:geochemical and experimental constraints from the type locality. Contr. Mineral. Petrol. ,97:333-351
[15] ［15］Morrison G W. 1980. Characteristics and tectonic setting of the shoshonite rockassociation. Lithos, 13:97～108
[16] ［16］Muller D, Groves D L. 1995. Potassic igneous rocks and associated gold-coppermineralization. Berlin: Springer-Verlag, 1 ～ 210
[17] ［17］Ningwu Project Group. 1978. The porphyrite iron deposit of Ningwu. Beijing:Geological Publishing House
[18] ［18］Pearce J A, Harris B W, Tindle A G. 1984. Trace element discrimination diagramsfor the tectonic interpretations of granitic rocks. J. Petrol. , 25:956-983
[19] ［19］Peccerillo A,TaylorS R. 1976. Geochmistry of Eocene calc-alkaline volcanic rocksfrom the Kastamonu area, northern Turkey.Contrib. Mineral. Petrol. , 58:63～81
[20] ［20］Pe-Piper G and Piper D J W. 1992. Geochemical variation with time in the Cenozoichigh-K volcanic rocks of the island of Lesbos,Greece: significance for shoshonitepetrogenesis. J. Volcan.Geotherm. Res. , 53:371-387
[21] ［21］Roberts M P and Clemens J D. 1993. Origin of high-potassium,calc-alkaline, I-typegranitoids. Geology, 21:825-828
[22] ［22］Rogers N W, Hawkesworth C J, Mattey D P et al. 1987. Sediment subduction and thesource of potassium in orogenic leucites.Geology, 15:451-453
[23] ［23］Shao JA, Hah QJ, Zhang LQ et al. 1999. Two kinds of vertical accretion of thecontinental crust: an example of the Da Hinggan Mrs. Acta Petrologica Sinica, 15(4):600-606 (in Chinese with English abstract )
[24] ［24］Tang Yongcheng, Wu Yanchang, Chu Guozheng et al. 1998. Geology of copper-goldpolymetallic deposits in the alongChangjiang area of Anhui Province. Beijing: GeologicalPublishing House, 1-351 (in Chinese)
[25] ［25］Turner S, Arnaud N, Liu J et al. 1993. Post-collision, shoshonitic volcanism onthe Tibetan Plateau: implications for convective thinning of the Lithosphere and thesource of ocean island basalts. J. Petrol., 37:45-71
[26] ［26］Wang D Z, Ren Q J, Chen K R. 1996. Charaterisitics of volcanic rocks in theshoshonite province, eastern China and their metallogenesis. Acta Geologica Sinica,70:23-34 (in Chinese with English abstract)
[27] ［27］Wang Sungshan, McDougall I. 1980. K-Ar and 40Ar/39Ar ages on Mesozoic volcanicrocks from the Lower Yangtze Volcanic Zone, southeastern China. J. Geol. Soc. Austral. ,27: 121-128
[28] ［28］Wang Y and Zhang Q. 2001. A granitoid complex from Badaling area, North China:composition, geochemical characteristics and its implications. Acta Petrologica Sinica,17(4):533-540
[29] ［29］Wang YJ, Fan WM, Guo F and Li X. 2001. Petrological and geochemicalcharacteristics of Mesozoic granodioritic intrusions in southeast Hunan province, China.Acta Petrologica Sinica,17(1):169-175
[30] ［30］Xing Fengming, Xu Xiang. 1998. The characteristics and origin of the shoshonitesaround the Yangtze River reaches of Anhui.Geol. Anhui, 8(2): 8-20 (in Chinese with Englishabstract)
[31] ［31］Xing Fengming. 1996. Petrological and Nd, Sr, Pb isotopic evidence for genesis ofMesozoic magmatic rocks in Nanjing-Wuhu area.Acta Petrol. Mineral. , 15:126-137 (inChinese with English abstract)
[32] ［32］Xu Z G, Sheng J F, Sun S P. 1999. A discussion on characteristics of shoshoniterock series (association) and some problems.Geological Review, 45 (supple.): 43 - 62 (inChinese with English abstract)
[33] ［33］Xue Huaiming, Tao Kuiyuan. 1989. New view on the Mesozoic volcanic sequences inNing-Wu. Geol. Jiangsu, (11):9～14 (in Chinese with English abstract)
[34] ［34］Yang Zhuliang, Shen Weizhou, Tao Kuiyuan et al. 1999. Sr, Nd and Pb isotopiccharacteristics of Early Cretaceous basaltic rocks from the coast of Zhejiang and Fujian:Evidences for ancient enriched mantle source. Scientia Geologica Sinica, 34 (1): 59-68 (inChinese with English abstract)
[35] ［35］Yu Xueyuan. 1986. Characteristics and origin of Mesozoic volcanic rocks inSoutheastern China. Acta Petrologica Sinica, 2(1): 15-25 (in Chinese with Englishabstract)
[36] ［36］Yue Wenzhe, Ding Baoliang. 1999. Study on Cretaceous stratigraphic sequence ofcontinental basin in Jiangsu. Volcano.Mineral. Res., 20: 287- 344 (in Chinese with Englishabstract)
[37] ［37］Zhang Qi, Qian Qing, Erchie Wang et al. 2001. Existence of East China Plateau inmid-late Yanshan period: implication from adakites. Scientia Geologica Sinica, 36: 248-255 (in Chinese with English abstract)
[38] ［38］Zhang Qi, Wang Yan, Qian Qing et al. 2001. The characteristics andtectonic-metallogenic significances of the Mesozoic adakites in eastern China. ActaPetrologica Sinica, 17(2): 236-244
[39] ［39］陈江峰,周泰禧,李学明等.1993.安徽南部燕山期中酸性侵入岩的源区锶、钕同位素制约.地球化学(3):261-274
[40] ［40］邓晋福,叶德隆,赵海玲等.1992.下扬子地区火山作用深部过程与盆地形成.北京:中国地质大学出版社
[41] ［41］郭峰,范蔚茗,王岳军等.2001.大兴安岭南段晚中生代双峰式火山作用.岩石学报,17:161-168
[42] ［42］李坤英.1982.中国东南部中生代火山岩的同位素年龄/时间和空间演化及其原始物质来源.中国地质科学院南京地质矿产研究所所刊,3:98-118
[43] ［43］李献华,周汉文,刘颍等.2001.粤西阳春中生代钾玄质侵入岩及其构造意义:Ⅱ.微量元素和Sr-Nd同位素地球化学.地球化学,30:57-65
[44] ［44］林强,葛文春,孙德有等.1998.中国东北地区中生代火山岩的大地构造意义.地质科学,33:129-139
[45] ［45］马昌前,杨坤光,唐仲华等.1994.花岗岩类岩浆动力学-理论方法及鄂东花岗岩类例析.武汉:中国地质大学出版社,1-260
[46] ［46］毛建仁,苏郁香,陈三元等.1990.长江中下游中酸性侵入岩与成矿.北京:地质出版社.1-191
[47] ［47］宁芜研究项目编写小组.1978.宁芜玢岩铁矿.北京:地质出版社
[48] ［48］邵济安,韩庆军,张履桥等.1999.陆壳垂向增生的两种方式:以大兴安岭为例.岩石学报,15:600-606
[49] ［49］汤德平,陈风贤.1992.中生代火山岩的成因和演化.见:邓晋福,叶德隆,赵海玲等著.下扬于地区火山作用深部过程与盆地形成.武汉:中国地质大学出版社,44～121
[50] ［50］唐永成,吴言昌,储国正等.1998.安徽沿江地区铜金多金属矿床地质.北京:地质出版社,1-351
[51] ［51］陶奎元,高天钧,陆志刚等.1988.东南沿海火山岩基底构造及火山-侵入作用与成矿关系.北京:地质出版社,1-43
[52] ［52］王德滋,任启江,邱检生等.1996.中国东部橄榄安粗岩省的火山岩特征及其成矿作用.地质学报,70:23-34
[53] ［53］王焰,张旗.2001.八达岭花岗杂岩的组成、地球化学特征及其意义.岩石学报,17(4):533-540
[54] ［54］王岳军,范蔚茗,郭峰,李旭.2001.湘东南中生代花岗闪长质小岩体的岩石地球化学特征.岩石学报,17(1):169-175
[55] ［55］吴利仁,齐进英,王听渡等.1982.中国东部中生代火山岩.地质学报,56(3):223-234
[56] ［56］邢凤鸣,徐祥.1998.安徽沿江地区橄榄安粗岩系的特点和成因:大陆橄榄安粗岩系一例.安徽地质,8(2):8-2058.
[57] ［57］邢凤鸣.1996.宁芜地区中生代岩浆岩的成因--岩石学与Nd、Sr、Pb同位素证据.岩石矿物学杂志,15:126-13759.
[58] ［58］徐志刚,盛继福,孙善平.1999.关于"橄榄玄粗岩系列(组合)"特征及某些问题的讨论.地质论评,45(增刊):43-6260.
[59] ［59］薛怀民,陶奎元.1989.宁芜地区中生代火山岩系列的新认识及其地质意义.江苏地质,(11):9～1461.
[60] ［60］杨祝良,沈渭洲,陶奎元等.1999.浙闽沿海早白垩世玄武岩锶、钕、铅同位素特征-古老富集型地幔的证据.地质科学,34:59-6862.
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