胶东昆嵛山杂岩中高锶花岗岩地球化学成因及其意义

doi:10.3321/j.issn:1000-0569.2004.03.001

CORC > 北京大学 > 地球与空间科学学院

	胶东昆嵛山杂岩中高锶花岗岩地球化学成因及其意义; Petrogenesis and implications of the sodium-rich granites from the Kunyushan Complex, eastern Shandong province.
	张华锋 ; 翟明国 ; 何中甫 ; 彭澎 ; 许保良
刊名	岩石学报
	2004
关键词	胶东地区昆嵛山高锶花岗岩地球化学岩石成因 geochemistry petrogenesis Kunyushan sodium-rich granites Jiaodong peninsula
DOI	10.3321/j.issn:1000-0569.2004.03.001
英文摘要	华北克拉通性质的胶东陆块之间。本文主要对其中具定向构造的垛崮山与瓦善高锶花岗岩体的地球化学成因及其地质意义的研究。垛崮山岩体岩性主要为花岗闪长岩,瓦善岩体主要为二长花岗岩。岩石化学特征表明两岩体为亚碱性岩石,属钙碱性系列和高钾钙碱性系列。SiO_2=69～71％,高Al(Al_2O_3>15％,SiO_2=70％),富碱:Na_2O=3.54～4.88％, K_2O=2.11～4.44％,K_2O+Na_2O=5.65～9.02％。Na_2O/K_2O=0.9～1.9,表明属Na质花岗岩。富集大离子亲石元素,如Ba、Sr(Ba>1440μg/g,Sr>650μg/g),而亏损高场强元素(如Nb...; The Kunyushan Complex emplaced between the SuLu Ultrahigh-Pressure-Metmorphic belt and the Jiaodong terran, eastern Shandong province, mainly consists of the Duogushan, Washan, Wuzhuashan, Laoshifen and Liulinzhuang granitoids. Here, we mainly discuss the geochemistry and petrogenesis of the Duogushan and Washan sodium-rich granites which belong to the calc-alkaline and high-potassium calc-alkaline series respectively. They have SiO2 = 69 similar to 71%, high aluminium ( Al2O3 > 15%, SiO2 = 70%) and alkaline contents including Na2O = 3.54 similar to 4.88%, K2O = 2.11 similar to 4.44% K2O + Na2O = 5.65 similar to 9.02% and Na2O/K2O = 0.9 similar to 1.9 consistent with Na-rich granite, LILE ( e.g. Ba > 1440mug/g, Sr > 650mug/g) and LREE enrichment but HFSE depletion ( e. g. Nb, Ta, P and Ti) in the primitive mantle normalized spidergram, and steep REE patterns ( La-n/Yb-n > 12, Y < 18mug/g and Yb < 2mug/g, no or weak anomalies of Eu). These geochemical features are similar to Archaean TTG, Adakite, Na-rich granite of Cordillera Blankca Batholith and as well as many other Mesozoic granites in eastern China. the typical calc-alkalic differentiation trend of arc volcanic suites is different from the trondhjemitic trend of the TTG and Adakite, but closely simlar to Na-rich granites from the Cordillera Blanca Batholith of Peru. The reported Sr-Nd isotopic components (Sr-87/Sr-86 i = 0.7097 similar to 0.7098, and epsilon(NJ) ( t) = - 19.6 similar to -20.0) and inherited magmatic zircons with ages of 700 similar to 800Ma from the Kunyushan sodium-rich granites, rule out genesis related to newly basaltic lower crust and mass from the Jiaodong block which has reported U-Pb concordant ages of 2600 similar to 2900Ma. There is no coeval basic or intermediate magma known from the Jiaodong erea, implys that these granites are unlikely to be derived by fractionation of mantle-derived magma or magmatic modification via magma mixing, fractionation and/ or AFC process reported for the genesis of other sodium-rich granites occurring in eastern China. Partial melts of young subducted ocean crust can also be excluded because no ocean crust occurs in the Su-Lu UHP metamorphic belt during the Mesozoic. Hence, the sodium-rich granites are most likely to be generated by dehydrational partial melting of thick mafic lower crust of the South China block as a result of basaltic underplating which is perhaps triggered by lithosphere thinning beneath North China Craton. The geochemistry of the Kunyushan sodium-rich granites with low Y, Yb contents and high Sr/Y, ( La/Yb)(n) ratios indicate that garnet and amphibole, but not feldspar, are dominant residues which would drop into lithosphere due to their relatively high density. Furthermore, the sodium-rich granites formation suggests that thickened lower mafic crust in response to continental collision, was still present between 160Ma and 140Ma, and as well as various petrogenesis of the sodium-rich granites in eastern China.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000222897200001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 22; 03; 369-380; 20
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/238570]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	张华锋,翟明国,何中甫,等. 胶东昆嵛山杂岩中高锶花岗岩地球化学成因及其意义, Petrogenesis and implications of the sodium-rich granites from the Kunyushan Complex, eastern Shandong province.[J]. 岩石学报,2004.
APA	张华锋,翟明国,何中甫,彭澎,&许保良.(2004).胶东昆嵛山杂岩中高锶花岗岩地球化学成因及其意义.岩石学报.
MLA	张华锋,et al."胶东昆嵛山杂岩中高锶花岗岩地球化学成因及其意义".岩石学报 (2004).