折多山花岗岩时代、成因及其动力学意义

doi:10.3321/j.issn:1000-0569.2006.02.008

CORC > 北京大学 > 地球与空间科学学院

	折多山花岗岩时代、成因及其动力学意义; Timing, petrogenesis and geodynamic significance of Zheduoshan Granitoids.
	刘树文 ; 王宗起 ; 闫全人 ; 李秋根 ; 张德惠 ; 王建国
刊名	岩石学报
	2006
关键词	折多山花岗岩 SHRIMP锆石年龄地球化学和Sr-Nd同位素部分熔融高压变质源岩鲜水河断裂 Zheduoshan granitoids SHRIMP zircon dating geochemistry and Sr-Nd isotope systematics partial melting high-pressure metamorphic source rocks Xianshuihe fault belts
DOI	10.3321/j.issn:1000-0569.2006.02.008
英文摘要	沿鲜水河断裂分布的折多山花岗岩由早期的中细粒花岗闪长岩、二长花岗岩和略晚的主体似斑状二长花岗岩、少量的伟晶岩和细晶岩构成。早期中细粒二长花岗岩的SHRIMP锆石U-Pb同位素定年表明其侵位结晶于18±0．3Ma,使折多山花岗岩岩浆侵位结晶年龄和鲜水河断裂开始活动的时间提前近6Ma。岩石中保存有818±47Ma和156±8Ma的继承锆石．表明存在扬子西缘元古宙和中生代陆壳物质的再循环。在K_2O对SiO_2分类图上,早期的中细粒花岗闪长岩和二长花岗岩落在钙碱性系列区域,似斑状二长花岗岩落在橄榄玄粗岩系列区域,两个系列岩石总体上为铝饱和到过饱和。中细粒花岗闪长岩具有中等的稀土总量(162×10~(...; Zheduoshan granitoids emplaced along Xianshuihe fault belt Consist Of earlier medium- to fine-grained granodiorite and monzogranite, slightly later predominated medium- to coarse-grained porphyry-like monzogranites and the latest granitoid pegmatites and aplites. The earlier medium- to fine-grained monzogranites have been dated by SHRIMP zircon U-Pb isotopes and an age of 18 +/- 0.3Ma is obtained. This SHRIMP zircon U-Pb age makes the time of emplacement of Zheduoshan granitoids and starting activation of the Xianshuihe fault belt, be predated for 6 Ma. Inherited zircons with 818 +/- 47 Ma and 156 +/- 8 Ma ages, respectively, are preserved in this sample. The earlier granodiorite and monzogranite samples were ploted into calc-alkaline and high-potassium calc-alkaline series domains and later porphyry-like monzogranite samples into shoshonite series domain in the K2O versus SiO2 diagram. All of these samples exhibit aluminium saturation to supersaturation. Earlier granodiorite samples display medium total REEs (162 x 10(-6) similar to 224 x 10(-6)), higher (La/Yb) (N) (=74 similar to 118) and positive Eu anomalies, and enrichment in LILEs, but depletion in the Nb, Ta, P and Ti in the primitive mantle normalized spider diagram, indicating that the granodioritic magma derived from lower degree of partial melting of calc-alkaline basaltic volcanic rocks. The earlier monzogranite samples show very similar geochemical characteristics to the earlier granodiorites, excepted that their total REEs and (La/Yb), are lower than these of granodiorites, Suggesting that the earlier monzogranite magma was most probably derived from lower degree partial melting of graywackes. Predominant later porphyry-like monzogranite samples display a wider total REE's (the highest arrived to 533 x 10(-6)), the (La/Yb) (N) (the highest to 523), Obvious negative Eu anomalies, and intensive enrichment in LILEs, but depletion in Nb, Ta, Sr, P and Ti in the primitive mantle normalized spider diagram. These porphyry-like monzogranites also exhibit (Sr-87/Sr-86), = 0.7084 similar to 0.7133 and epsilon(Nd)(t) = -5.67 similar to -8.69, suggesting that the later monzogranitic magma was most probably derived from lower degree partial melting of Proterozoic Upper continental materials of siltstones and/or shales. These geochemistry features in various kind of granitoids in Zheduoshan intrusion indicate that the partial melting source materials have inherited some geochemisty characteristics of Proterozoic active continental margin arid underwent high-pressure metamorphism, and partial melting residuals should dominate garnet. The partial melting was probably produced with early shear melting process of Xianshuihe fault belt, also occurred strong compression before the magmatism to produce the high-pressure metamorphism.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000236152700008&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); 9; 02; 343-352; 22
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/48745]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	刘树文,王宗起,闫全人,等. 折多山花岗岩时代、成因及其动力学意义, Timing, petrogenesis and geodynamic significance of Zheduoshan Granitoids.[J]. 岩石学报,2006.
APA	刘树文,王宗起,闫全人,李秋根,张德惠,&王建国.(2006).折多山花岗岩时代、成因及其动力学意义.岩石学报.
MLA	刘树文,et al."折多山花岗岩时代、成因及其动力学意义".岩石学报 (2006).