大兴安岭北端洛古河东花岗岩的地球化学、SHRIMP锆石U-Pb年龄和岩石成因

CORC > 北京大学 > 地球与空间科学学院

	大兴安岭北端洛古河东花岗岩的地球化学、SHRIMP锆石U-Pb年龄和岩石成因; Geochemistry, zircon SHRIMP U-Pb age and petrogenesis of the East Luoguhe granites at the northern end of the Great Hinggan Range
	武广 ; 陈衍景 ; 赵振华 ; 赵太平 ; 李之彤 ; 张哲
刊名	岩石学报
	2009
关键词	洛古河东早白垩世花岗岩锆石SHRIMP铀-铅年龄元素地球化学同位素地球化学大兴安岭 East Luoguhe Early Cretaceous granite Zircon SHRIMP U-Pb age Element geochemistry Isotope geochemistry Great Hinggan Range
英文摘要	大兴安岭北端漠河县洛古河东岩体主要岩石类型为二长花岗斑岩、正长花岗斑岩和石英二长斑岩,内部可见闪长质微粒包体,属高钾钙碱性Ⅰ型花岗岩。花岗岩的元素地球化学和锆石SHRIMP铀-铅年代学研究结果表明,洛古河东岩体形成于早白垩世,其花岗斑岩体的锆石SHRIMP铀-铅年龄为129.8±2.2Ma。花岗岩的SiO_2含量介于68.03%～74-32%之间,Al_2O_3含量介于13.06%～14.55%之间,Na_2O/K_2O介于0.45～0.86之间,铝饱和指数为0.94～1.11,Mg~#指数介于18～42之间且多小于30。稀土元素总量为160.00×10~(-6)～235.15×10~(-6)...; The East Luoguhe intrusion in Mohe County, Heilongjiang Province, located in the northern end of the Great Hinggan Range, is mainly composed of monzogranite-porphyry, syenogranite-porphyry and quartz monzonite-porphyry, with minor dioritic microgranular enclave. The intrusion belongs to I-type granite, with affinity to high-K calc-alkaline series. The SHRIMP zircon U-Pb age of the granite-porphyry is 129.8 +/- 2.2 Ma, indicating that the intrusion formed in Early Cretaceous. Its SiO(2) and Al(2)O(3) contents range 68.03% similar to 74.32% and 13.06% similar to 14.55%, respectively. The Na(2)O/K(2)O ratios range 0.45 similar to 0.86, ASI values from 0.94 to 1.11 (mostly <1.1 and the Mg(#) index from 18 to 42 (mostly <30). The REE content is between 160.00 x 10(-6) and 235.15 x 10(-6), with delta Eu of 0.31 similar to 0.52 (average 0.41) and (La/Yb)(N) ratios of 8.99 similar to 17.87 (average 13.82). The East Luoguhe intrusion is characterized by low-Sr (118 x 10(-6) similar to 268 x 10(-6)), high-Y (16.9 x 10(-6) similar to 26.1 x 10(-6), generally >18 x 10(-6)), and low Sr/Y ratios (5.62 similar to 13.81). The intrusion is enriched in Rb, Th, U, K, Zr, Hf and LREE (e. g. La, Ce, Nd and Sm), but strongly depleted in Ba, Sr, P and Ti, with notable depiction of Nb and Ta. The geochemical signatures above are similar to those of post-collisional granitoids, Suggesting that the East Luoguhe intrusion call be classified into the group of post-collisional granites. The intrusion has low initial (87)Sr/(86)Sr ratio (0.702486 similar to 0.707269, average 0.705434), clear negative epsilon(Nd) (t) value (-3.45 similar to -2.64, average -3.01), young Nd-model age (969 similar to 1131 Ma, average 1018 Ma), and extremely low delta(18) O ratio (-8.1 parts per thousand to 4.1 parts per thousand for K-feldspar). And the (206)Pb/(204)Pb (18.5939 similar to 18.6721, average 18.6426), (207)Pb/(204)Pb (15.6019 similar to 15.6058, average 15.6035) and (208)Pb/(204)Pb (38.4058 similar to 38.5249, average 38.4613) ratios for K-feldspar are relatively high. The Nd-Sr-Pb-O isotope systematics shows that the intrusion originated from partial melting of a source with remarkable mantle-derived components. The source is likely the juvenile crust formed during the convergence of Rodinia supercontinent at the transition from Mesoproterozoic to Neoproterozoic. Given that the Paleo-Asian Ocean was finally closed at the end of Late Paleozoic, followed by closing of the Mongol-Okhotsk Ocean during Permian-Middle Jurassic, the East Luoguhe intrusion of Early Cretaceous age must be formed in the collision regime between the Siberia and Mongol-Sinokorea continents, especially in a tectonic transition setting from compression to extension.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000265945400001&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); 12; 02; 233-247; 25
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/225255]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	武广,陈衍景,赵振华,等. 大兴安岭北端洛古河东花岗岩的地球化学、SHRIMP锆石U-Pb年龄和岩石成因, Geochemistry, zircon SHRIMP U-Pb age and petrogenesis of the East Luoguhe granites at the northern end of the Great Hinggan Range[J]. 岩石学报,2009.
APA	武广,陈衍景,赵振华,赵太平,李之彤,&张哲.(2009).大兴安岭北端洛古河东花岗岩的地球化学、SHRIMP锆石U-Pb年龄和岩石成因.岩石学报.
MLA	武广,et al."大兴安岭北端洛古河东花岗岩的地球化学、SHRIMP锆石U-Pb年龄和岩石成因".岩石学报 (2009).