克里阳钾镁煌斑岩同位素地球化学特征  

Isotope Geochemical Characteristics of Lamproite from Keliyang, Xinjiang

作　　者：赵磊[1] 李友枝 崔彬[1] 张照志[3] 李剑[1] 柳玉龙[1] 

机构地区：[1]中国地质大学,北京100083 [2]国家地质调查局发展中心,北京100037 [3]中国国土资源经济研究院,河北燕郊101149

出　　处：《地球学报》2003年第6期599-602,共4页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目 ( 4 9973 0 13 );国家地质调查局 (科 [2 0 0 3 ] 0 0 3 0 1)资助

摘　　要：通过研究表明 ,克里阳钾镁煌斑岩的δ13 C值为 - 2 .7‰～ - 3.3‰ ,δ18O值为 +14 .5 7‰～ +16 .4 3‰。其相容元素Cr、Ni,不相容元素Ba、Sr、Nb、Ta、Zr、Hf、Th含量比较亏损 ,惰性元素及放射性生热元素等 (除U外 )均较亏损 ,极亏损高场强元素Nb、Ti、Ta ,说明其产出可能与古俯冲作用有关。这些特征均表明 ,该区钾镁煌斑岩比较完好地保存着源区特征。克里阳钾镁煌斑岩的Sr初始比值为 0 .70 80 7,与国际同类岩石相比有些偏高 ,在中国属中度 ;Pb同位素比值2 0 6Pb/2 0 4Pb为 18.35 5 6。从Pb、Sr同位素组成及其他地球化学特征来看 。In this paper, the authors have mainly studied stable and radioactive isotope characteristics of lampoite from Keliyang, Xinjiang.δ 13C andδ 18O are -2.7～-3.3‰ and +14.57～+16.43‰ respectively. The content of compatible elements Cr and Ni and that of incompatible elements Ba, Sr, Nb, Ta, Zr, Hf and Th are relatively depleted, the inert elements and radioactive heat-generating elements are all relatively depleted except for U, and the high field-density elements Nb, Ti and Ta are strongly depleted, suggesting that the origin of the lamproite is related to the subduction. All of these characteristics indicate that the lamproite has preserved the features of its source area. A comparison is made between this lamproite and lamproite in other areas of the world. The initial Sr ratio is 0.70807,which is somewhat high compared with the similar rocks in the world. The 206Pb/ 204Pb ratio is 18.3556, which is rather high. From the Pb and Sr isotopic composition and other geochemical characteristics of the lamproite, it is concluded that it was produced through the mixture of the depleted mantle with the recycling crustal materials.

关 键 词：克里阳 钾镁煌斑岩 稳定同位素 放射性成因同位素 

分 类 号：P597.2[天文地球—地球化学]