苏鲁造山带五莲地区岩浆岩元素和同位素地球化学研究
Geochemistry of elements and isotopes in igneous rocks from the Wulian region in the Sulu orogen
-
摘要: 对苏鲁造山带五莲地区新元古代和中生代岩浆岩分别进行了主量元素、微量元素、Sr-Nd同位素和氧同位素研究。结果表明，新元古代花岗岩具有显著的LREE富集，高场强元素Nb、Ta、P和Ti负异常，δNd（t）为-12．6～-6．9，可能与古元古代老地壳物质再循环有关、锆石δ^18O值为-1．02～7．60℃，变化范围较大，近半数样品明显低于典型地幔δ^18O”0值。新元古代辉长岩具有板内裂谷环境的特征，其εNd（t）在1．6～5．3之间，说明其岩浆起源于亏损地幔，但是经受了一定程度的地壳混染作用，唯一一个辉长岩样品的锆石δ^18O值与部分花岗岩锆石δ^18O值一样，明显高于典型地幔值，可能是基性岩浆在沿裂谷喷发过程中经历了低温热液蚀变，随后又发生破火山口垮塌，导致蚀变玄武岩在岩浆房重熔而形成高δ^18O岩浆。中生代花岗岩和闪长岩表现出明显的高场强元素（Nd、Ta、P和Ti）负异常以及显著的LREE富集．εNd（t）值很低（-19．2～-15．3），同样是由古老地壳物质部分熔融形成、其锆石δ^18O变化范围为3．19～6．43％。，大多数样品与典型地幔锆石一样。石英与锆石之间大都达到并保存了氧同位素平衡分馏，而其它矿物（如长石、黑云母和角闪石等）与锆石之间由于受到岩浆期后亚固相热液蚀变而大都表现出明显的氧同位素不平衡分馏．元素和氧同位素特征表明，中生代闪长岩可能是基性下地壳脱水部分熔融并经过结晶分异形成的；花岗岩则可能是由中性下地壳的脱水部分熔融形成的。新元古代花岗岩与中生代花岗岩在微量元素配分模型和Sr-Nd同位素组成上具有十分相似的特征，因此未经历强烈热液蚀变的新元古代花岗质侵入岩可能是中生代花岗岩的原岩，但这些新元古代岩浆岩的锆石δ^18O变化范围较大，与中生代岩浆岩相比在流体活动性元素含量上也存在差别，这可能是由于新元古代岩浆岩侵位深度比中生代岩浆岩源区所处深度相对较浅所致。现有的研究结果表明，新元古代岩浆岩的形成与约740～760Ma的Rodinia超大陆裂解有关的裂谷岩浆活动有关，新生地壳物质作为热源启动了热液蚀变，并局部形成了低δ^18O岩浆。而中生代岩浆岩则是俯冲陆壳在加厚造山带背景下的部分熔融产物，岩浆源区物质由于所处深度较大没有受到明显的高温大气降水热液蚀变。
-
Key words:
- Zircon /
- Oxygen isotope /
- Neoproterozoie /
- Mesozoic /
- Igneous rocks /
- Hydrothermal alteration
-
-
[1] Ayers J C, Watson E B. 1991. Solubility of apatite, monazite, zircon,and rutile in supercritical aqueous fluids with implications for subduction zone geochemistry. Phil Trans R Soc London, A335: 365- 375
[2] Bacon C R, Adami L H, and Lanphere M A. 1989. Direct evidence for the origin of low -18O silicic magmas: Quenched samples of a magma chamber\'s partially fused granitoid walls, Crater Lake,Orogen. Earth Planet. Sci. Lett., 96:199-208
[3] Balsely S D and Gregory R T. 1998. Low - 18O magmas: Why are they so rare? Earth Planet. Sci. Lett. , 168: 123 - 136
[4] Beard J S and Lofgren G E. 1991. Dehydration melting and watersaturated melting of basaltic and andesitic greenstones and amphibolites at 1,3, 6.9 kb. J. Petrol. , 32:365 -401
[5] Bindeman I N and Valley J W. 2001. Low δ18 O rhyolites from Yellowstone: magmatic evolution based on analysis of zircon and individual phenocrysts. J. Petrol. , 42:1491 - 1517
[6] Bryant DL, Ayers JC, Gao S, Miller CF, Zhang H. 2004. Geochemical,age, and isotopic constraints on the location of the Sino - Korean/Yangtze Suture and evolution of the Northern Dabie Complex, east central China. Geol. Soc. Am. Bull., 116:698-717
[7] Chen B, Jahn B -m, Wei C. 2002a. Petrogenesis of Mesozoic granitoids in the Dabie UHP complex, Central China: trace element and Nd-Sr isotope evidence. Lithos, 60: 67 - 88
[8] Chen B, Jahn B-m, Ye K, Liu J B. 2002b. Cogenetic relationship of the Yangkou gabbro -to-granite unit, Su-Lu terrane, eastern China, and implications for UHP metamorphism. Journal of the Geological Society, Londan, 159: 457 -467
[9] Chen JF, Xie Z, Liu SS, Li XM and Foland KA. 1995. Cooling age of Dabie orogen, China, determined by 40Ar -39 Ar and fission track techniques. Sci. China (B), 38:749-757
[10] Dodson MH. 1973. Closure temperature in cooling geochronological and petrological systemes. Contrib. Mineral. Petrol. 40:259 -274
[11] Drummond MS, Defant MJ and Kepezhinskas PK. 1996. Petrogenesis of slab-derived trondhjemite- tonalite-dacite/adakite magmas. Trans.R. Soc. Edinb Earth Sci. , 87:205 -215
[12] Eiler JM. 2001. Oxygen isotope variations of basaltic lavas and upper mantle rocks. In: Valley J. W. and Cole D. R. eds. Stable Isotope Geochemistry. Rev. Mineral. , 43:319-364
[13] Fan WM, Guo F, Wang Y J, Zhang M. 2004. Late Mesozoic volcanism in the northern Huaiyang tectono-magmatic belt, central China: partial melts from a lithospheric mantle with subducted continental crust relicts beneath the Dabie orogen? Chemical Geology, 209:27 -48
[14] Forester RW and Taylor HP Jr. 1977. 18O/16O, D/H, and 13C/12C studies of the Tertiary igneous complex of Skye, Scotland. Am. J.Sci. , 277: 136 - 177
[15] Fortier SM and Giletti BJ. 1989. An empirical model for predicting diffusion coefficients in silicate minerals. Science, 245:1481 -1484
[16] Friedman L, Lipman P, Obradovich JD et al. 1974. Meteoric water in magmas. Science, 184:1069-1072
[17] Gao S, Luo TC, Zhang BR. 1998. Chemical composition of the continental crust as revealed by studies in East China. Geochimica.Cosmochim. Acta, 62: 1959 - 1975
[18] Guo F, Fan WM, Wang Y J, Sun M. 2004. Origin of early Cretaceous calc-alkaline lamprophyres from the Sulu orogen in eastern China:implications for enrichment processes beneath continental collisional belt. Lithos, 78:291 -305
[19] Hacker BR, Wang QC. 1995. Ar/Ar geochronology of ultrahigh-pressure metamorphism in central China. Tectonics, 14:994 -1006
[20] Hacker BR, Ratschbacher L, Webb L, Ireland T, Walker D and Dong S.1998. U/Pb zircon ages constrain the architecture of the ultrahighpressure Qinling-Dabie Orogen, China. Earth Planet. Sci. Lett. ,161:215 -230
[21] Hacker BR, Ratschbacher L, Webb L, McWilliams MO, Ireland T,Calvert A, Dong S, Wenk HR and Chateigner D. 2000. Exhumation of ultrahigh-pressure continental crust in east central China: Late Triassic-Early Jurassic tectonic unroofing. J. Geophys. Res.,105B: 13339 - 13364
[22] Hildreth W, Christiansen RL and O\'Neil JR. 1984. Catastrophic isotope modification of rhyolitic magma at times of caldera subsidence,Yellowstone Plateau Volcanic Field. J. Geophys. Res. , 89: 8339 -8369
[23] Huppert HE and Sparks RS. 1988. The generation of granitic magmas by intrusion of basalt into continental crust. J. Petrol. , 29: 599 - 624
[24] Jahn B-m, Wu F, Lo C-H, Tsai C -H. 1999. Crustal-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. Chem.Geol. , 157: 119 - 146
[25] Jahn B-m, Rumble D, Liou JG. 2003. Geochemistry and isotope tracer study of UHP metamorphic rocks. In: Carswell, D. A. ,Compagnoni, R. (eds.) , Ultrahigh Pressure Metamorphism. EMU Notes Mineral., vol. 5, pp. 365- 414. EOtvOs Univ. press,Budapest
[26] Kennedy M J, Runnegar B, Prave A R et al. 1998. Two or four Neoproterozoic glaciations? Geology, 26: 1059 - 1063
[27] Li SG, Nie YH, Hart SR et al. 1998a. Interaction between subducted continental crust and the mantle-I. major and trace elements of the syn-collision mafic-ultramafic rocks. Sci. China ( D), 41 ( 5 ): 535- 552
[28] Li SG, Nie YH, Hart SR, Zhang ZQ. 1998b. Interaction between subducted continental crust and the mantle-Ⅱ. Sr and Nd isotopic geochemistry of the syncollisional mafic-ultramafic intrusions in the Dabie Mountains. Sci. China (D) , 41 (6): 632 - 638
[29] Li SG, Hong JA, Li HM, Jiang LL. 1999. U-Pb zircon ages of the pyroxenite-gabbro intrusions in Dabie Mountains and their geological implications. Geol. Jour. China Univ. (in Chinese with English abstract), 5:351 -355
[30] Li XH. 1999. U-Pb zircon ages of granites from the southern margin of the Yangtze Block: Timing of Neoproterozoic Jinning Orogeny in SE China and implications for Rodinia Assembly. Precambr. Res. , 97:43 ～ 57
[31] Li XH, Li ZX, Ge W et al. 2003. Neoproterozoic granitoids in South China: Crustal melting above a mantle plume at ca. 825Ma?Precambr. Res. , 122:45 ～83
[32] Ma C, Li Z, Ehlers C, Yang K and Wang R. 1998. A post-collisional magmatic plumbing system: Mesozoic granitoid plutons from the Dabieshan high-pressure and ultrahigh-pressure metamorphic zone,east-central China. Lithos, 45: 431 -456
[33] Martin H. 1999. Adakitic magmas: morden analogues of Archean granitoids. Lithos, 46: 411 -429
[34] Pati(n)o-Douce A E and Beard J S. 1995. Dehydration-melting of biotite gneiss and quartz amphibolite from 3 to 15 kbar. J. Petrol. , 36:707 - 738
[35] Pati(n)o-Douce A E and McCarthy. 1998. Melting of crustal rocks during continental collision and subduction. In: When Continents Collide:Geedynamics and Geochemistry of Ultrahigh-pressure Rocks (eds.B.R. Hacker and J. G. Liou ), Kluwer Academic Publishers,Dordrecht, p. 27 -55
[36] Prave AR. 1999. Two diamictites, two cap carbonates, two δ13C excursions, two rifts: The Neoproterozoic Kingston Peak Formation,Death Valley, California. Geology, 27:339 ～ 342
[37] Rapp RP and Watson EB. 1995. Dehydration melting of metabasalt at 8-32 kbar: implications for continetal growth and crust-mantle recycling. J. Petrol., 36:891 -931
[38] Rumble D, Giorgis D, Oreland T, Zhang ZM, Xu HF, Yui TF, Yang JS, Xu ZQ and Liou JG. 2002. Low δ18O zircons, U-Pb dating,and the age of the Qinglongshan oxygen and hydrogen isotope anomaly near Donghai in Jiangsu province, China. Geochim.Cosmochim. Acta, 66: 2299 - 2306
[39] Rushmer T. 1991. Partial melting of two amphibolites: contrasting experimental results under fluid-absent conditions. Contrib.Mineral. Petrol. , 107: 41 -59
[40] Rushmer T. 1993. Experimental high pressure granulites: some applications to natural mafic xenolith suites and Archean granulite terranes. Geology, 21:411 -414
[41] Sen C and Dunn T. 1994. Dehydration melting of a basaltic composition amphibolite at 1. 5 and 2.0 GPa: implications for the origin of adakites. Contrib. Mineral. Petrol. , 117:394-409
[42] Sheppard SMF and Taylor HP Jr. 1974. Hydrogen and oxygenisotope evidence for the origins of water in the Boulder batholith and the Butte ore deposits. Econ. Geol. 69: 926 - 946
[43] Taylor HP Jr. 1977. Water/rock interactions and the origin of H2O in granitic batholiths. J Geol Soc London. 133:509 -558
[44] Taylor HP Jr and Sheppard S M F. 1986. Igneous rocks: I. Processes of isotopic fractionation and isotope systematics. In: Valley JW, Taylor HP Jr. and O\'Neil JR. ( eds. ) Stable Isotopes in High Temperature Geological Processes. Rev. Mineral., 16:227-271
[45] Tole MP. 1985. The kinetics of dissolution of zircon( ZrSiO4 ). Geochim Cosmochim Acta, 49:453-458
[46] Tsai CH, Lo C -H, Liou JG et al. 2000. Evidence against subductionrelated magmatism for the Jiaoziyan gabbro, northern Dabie Shan,China. Geology, 28(10): 943 -946
[47] Watson EB. 1979. Zircon saturation in felsic liquids: experimental results and applications to trace element geochemistry. Contrib. Mineral.Petrol. , 70:407-419
[48] Watson EB and Harrison. 1983. Zircon saturation revisited: temperature and composition effects in a variety of crustal magma types. Earth Planet Sci Lett, 64:295 - 304
[49] Watson EB and Cherniak DJ. 1997. Oxygen diffusion in zircon. Earth Planet. Sci. Lett. , 148:527-544
[50] Wei CS, Zheng YF, Zhao ZF and Valley JW. 2002. Oxygen and neodymium isotope evidence for recycling of juvenile crust in northeast China. Geology, 30: 375 - 378
[51] Wolf MB and Wyllie PJ. 1994. Dehydration-melting of amphibolite at 10kbar: effects of temperature and time. Contrib. Mineral. Petrol. ,115:369-383
[52] Wu YB, Zheng YF, Gong B, Tang J, Zhao ZF and Zha XP. 2004. Zircon U-Pb ages and oxygen isotope compositions of the Luzhenguan magmatic complex in the Beihuaiyang zone. Acta Petrologica Sinica,20 (5): 1007 -1024 (in Chinese with English abstract)
[53] Wu YB, Zheng YF and Zhou JB. 2004. Neoproterozoic granitoid in northwest Sulu and its bearing on the North China-South China Blocks boundary in east China. Geophysical Research Letters, 31,L07616, doi: 10. 1029/2004GL019785
[54] Xie Z, Chen JF, Zhang X, Li HM, Zhou TX, Yang G. 2002. Geochronology of Neoproterozoic malic intrusions in North Huaiyang area. Acta Geoscience Sinica, 23 (6): 517 -520 (in Chinese with English abstract)
[55] Zhang H, Gao S, Zhong Z, Zhang B, Zhang L, and Hu S. 2002. Geochemical and Sr-Nd-Pb isotopic compositions of Cretaceous granitoids: constraints on tectonic framework and crustal structure of the Dabieshan ultrahigh-pressure metamorphic belt, China. Chem.Geol. , 186:281 -299
[56] Zhao ZF, Zheng YF, Wei CS, Wu YB. 2004. Zircon isotope evidence for recycling of subducted continental crust in post-collisional granitoids from the Dabie terrane in China. Geophys. Res. Lett. ,31, L22602, doi: 10. 1029/2004GL021061
[57] Zhao ZF, Zheng YF, Wei CS, Wu YB, Chen FK and Jahn B -m. 2005. Zircon U-Pb age, element and C-O isotope geochemistry of postcollisional mafic-ultramafic rocks from the Dabie orogen in eastcentral China. Lithos, 83:1 - 28
[58] Zheng YF. 1989. Influence of the nature of the initial Rb-Sr system on isochron validity. Chem. Geol,. 80: 1 - 16
[59] Zheng YF. 1991. Calculation of oxygen isotope fractionation in metal oxides. Geochim. Cosmochim. Acta, 55:2299-2307.
[60] Zheng YF. 1993a. Calculation of oxygen isotope fractionation in anhydrous silicate minerals. Geochim. Cosmochim. Acta, 57:1079-1091
-
计量
- 文章访问数: 6918
- PDF下载数: 7389
- 施引文献: 0
下载: