摘要
北祁连走廊南山北坡西水地区的加里东期大野口岩体中闪长玢岩地球化学的研究表明,该套岩石的SiO_2>56%,Al_2O_3>15%,Na_2O>K_2O,富集大离子亲石元素和轻稀土元素,具正Eu异常,富集Sr元素、亏损重稀土元素Yb和Y,具有较高的Sr/Y值,表现出明显的埃达克岩的地球化学性质。结合岩体产出的时空位置,认为大野口岩体形成于奥陶纪与板块俯冲作用相关的俯冲洋壳部分熔融和壳幔岩浆混合作用。
Geochemical studies of diorite porphyrite in Xishui area of Zoulangnanshan within North Qilian Mountain show that the rock is characterized by SiO_2>56%, Al_2O_3>15%, Na_2O>K_2O%, LILE and LREE enrichment, positive Eu anomalies, Sr enrichment,depletion of heavy rare earth elements Yb and Y, and higher Sr/Y ratios, showing obvious geochemical characteristics of adakite. According to the regional geological study, the authors hold that Dayekou diorite porphyrite was formed in the Caledonian Ordovician period associated with subduction of the oceanic crust partial melting and crust-mantle magma mixing.
引文
[1]王焰,张旗,钱青.埃达克岩(adakite)的地球化学特征及其构造意义[J].地质科学,2000,35(2):251-256.
[2]罗照华,柯珊,谌宏伟.埃达克岩的特征、成因及构造意义[J].地质通报,2002,21(7):436-440.
[3]张旗,王焰,刘伟,等.埃达克岩的特征及其意义[C]//中国科学院地质与地球物理研究所2002学术论文摘要汇编,2002:431-435.
[4]翟明国.埃达克岩和大陆下地壳重熔的花岗岩类[J].岩石学报,2004,20(2):193-194.
[5]Castillo P R.Adakite petrogenesis[J].Lithos,2012,134(3):304-316.
[6]Atherton M P,Petford N.Generation of sodium-rich magmas from newly underplated basaltic crust[J].Nature International Weekly Journal of Science,1993,362(6416):144-146.
[7]Muir R J,Ireland T R,Weaver S D,et al.Ion microprobe dating of Paleozoic granitoids:Devonian magmatism in New Zealand and correlations with Australia and Antarctica[J].Chemical Geology,1996,127(1/3):191-210.
[8]Defant M J,Xu J F,Kepezhinskas P,et al.Adakites:some variations on a theme[J].Acta Petrologica Sinica,2002,18(2):129-142.
[9]张旗,许继峰,王焰,等.埃达克岩的多样性[J].地质通报,2004,23(9):959-965.
[10]邱瑞照,邓晋福,周肃,等.陆壳岩石化学结构建立方法探讨[J].地球学报,2006,27(3):259-270.
[11]夏林圻,夏祖春.北祁连山早古生代洋脊-洋岛和弧后盆地火山作用[J].地质学报,1998,(4):301-312.
[12]杜远生,朱杰,韩欣,等.从弧后盆地到前陆盆地——北祁连造山带奥陶纪—泥盆纪的沉积盆地与构造演化[J].地质通报,2004,23(9/10):911-917.
[13]徐学义,王洪亮,陈隽璐,等.中祁连东段兴隆山群基性火山岩锆石U-Pb定年及岩石成因研究[J].岩石学报,2008,24(4):827-840.
[14]苏建平,张新虎,胡能高,等.中祁连西段野马南山埃达克质花岗岩的地球化学特征及成因[J].中国地质,2004,31(4):365-371.
[15]王金荣,吴春俊,蔡郑红,等.北祁连山东段银硐粱早古生代高镁埃达克岩:地球动力学及成矿意义[J].岩石学报,2006,22(11):2655-2664.
[16]常华进.北祁连东段银硐梁埃达克岩的发现及其地质意义[D].兰州大学硕士学位论文,2006.
[17]李大民.甘肃北祁连毛藏寺埃达克岩及其成因类型[J].地质科学,2012,47(2):347-359.
[18]夏林圻,李向民,余吉远,等.祁连山新元古代中—晚期至早古生代火山作用与构造演化[J].中国地质,2016,43(4):1087-1138.
[19]闫臻,肖文交,刘传周,等.祁连山老君山砾岩的碎屑组成和源区大地构造背景[J].地质通报,2006,25(1):83-98.
[20]王永和,焦养泉,李建星,等.中祁连北缘奥陶纪岩浆弧地层[J].现代地质,2008,22(5):724-732.
[21]欧健.北祁连东段早古生代花岗岩成因及构造意义的初步研究[D].兰州大学硕士学位论文,2009.
[22]秦海鹏.北祁连造山带早古生代花岗岩岩石学特征及其与构造演化的关系[D].中国地质科学院博士学位论文,2012.
[23]Maniar P D,Piccoli P M.Tectonic discrimination of granitoids[J].Geological Society of America Bulletin,1989,101(5):635-643.
[24]Frost B R,Barnes C G,Collins W J,et al.A Geochemical Classification for Granitic Rocks[J].Journal of Petrology,2001,42(11):2033-2048.
[25]Sun S S,Mcdonough W F.Chemical and isotopic systematics of oceanic basalts:implications for mantle composition and processes[J].Geological Society London Special Publications,1989,42(1):313-345.
[26]Drummond M S,Defant M J,Kepezhinskas P K.Petrogenesis of slab-derived trondhjemite-tonalite-dacite/adakite magmas[J].Transactions of the Royal Society of Edinburgh Earth Sciences,1996,87(1/2):205-215.
[27]Brenan J M,Mcdonough W F,Ash R.An experimental study of the solubility and partitioning of iridium,osmium and gold between olivine and silicate melt[J].Earth&Planetary Science Letters,2005,237(3/4):855-872.
[28]Defaut M J,Drummoud M S.Derivation of some mordern are magma by melting of young subducted lithosphere[J].Nature.1990,347:662-665.
[29]Bourdon E,Eissen J,Monzier M,et al.Adakite-like lavas from Antisana Volcano(Ecuador):Evidence for slab melt metasomatism beneath Andean Northern Volcanic Zone[J].J.Petrol.,2002,43(2):199-217.
[30]Topuz G,Altherr R,Schwarz W H,et al.Post-collisional plutonism with adakite-like signatures:the Eocene Sarayc?k granodiorite(Eastern Pontides,Turkey)[J].Contributions to Mineralogy&Petrology,2005,150(4):441-455.
[31]Defant M J,Drummond M S.Mount St.Helens:potential example of the partial melting of the subucted lithosphere in a volcanic arc[J].Geology,1993,21:547–550.
[32]Prouteau G,Scaillet B,Pichavant M,et al.Evidence for mantle metasomatism by hydrous silicic melts derived from subducted oceanic crust[J].Nature,2001,410:197–200.
[33]朱涛,王洪亮,徐学义,等.敦煌地块南缘石炭纪埃达克岩的发现及其地质意义[J].岩石学报,2014,30(2):491-502.
[34]Wang Q,Mcdermott F,Xu J F,et al.Cenozoic K-rich adakitic volcanic rocks in the Hohxil area,northern Tibet:Lower-crustal melting in an intracontinental setting[J].Geology,2005,33(6):465-468.
[35]Gao S,Rudnick R L,Yuan H L,et al.Recycling lower continental crust in the North China craton[J].Nature,2004,432(7019):892-897.
[36]Defant M J,Pavel K.Reply to“Comment on‘Evidence suggests slab melting in arc magmas’”[J].Eos.Transactions American Geophysical Union,2002,83(23):256-257.
[37]张旗,王元龙,张福勤,等.埃达克岩与斑岩铜矿[C]//中国科学院地质与地球物理研究所2002学术论文摘要汇编.2002:85-90.
[38]Sajona F G,Maury R C,Prouteau G,et al.Slab melt as metasomatic agent in island arc magma mantle sources,Negros and Batan(Philippines)[J].Island Arc,2000,9(4):472–486.
[39]王涛,王宗起,闫臻,等.南秦岭大堡组奥陶纪洋岛玄武岩的识别及其构造意义:来自地球化学和年代学证据[J].岩石学报,2009,25(12):3241-3250.
[40]高山,张本仁,金振民,等.秦岭-大别造山带下地壳拆沉作用[J].中国科学,1999,29(6):532-541.
[41]Kuehner S M,Laughlin J R,Grossman L,et al.Determination of trace element mineral/liquid partition coefficients in melilite and diopside by ion and electron microprobe techniques[J].Geochimica Et Cosmochimica Acta,1989,53(12):3115-3130.
[42]Castillo P R.An overview of adakite petrogenesis[J].Chinese Science Bulletin,2006,51(3):257-268.
[43]冯益民.祁连山大地构造与造山作用[M].北京:地质出版社,1996.
[44]陈育晓,夏小洪,宋述光.北祁连山西段志留纪高硅埃达克岩:洋壳减压熔融的证据[J].科学通报,201,22:2072-2085.
[45]夏林圻,夏祖春.北祁连山古洋壳火山作用基本特征[C]//中国矿物学岩石学地球化学研究新进展学术交流会.1994.
[46]夏林圻,夏祖春,徐学义.北祁连山奥陶纪弧后盆地火山岩浆成因[J].中国地质,2003,30(1):48-60.