摘要
出露于新疆西准噶尔北缘萨吾尔山北坡哈尔交一带的哈尔交岩体和阔依塔斯岩体同时形成于早二叠世的拉张环境 ,但地质、地球化学特征存在明显差异。前者Na2 O +K2 O、Zr、Hf偏高 ,Rb、Sr、Ba、Nb、Th、Rb/Sr、Rb/Ba偏低 ,∑REE =99.6 6～ 2 4 9.4 7,平均为 177.0 8,δEu =0 .6 6～0 .77,平均 0 .72。与区内华力西中期形成的“I”型花岗岩中的酸性岩地球化学特征相近 ,为“I”型花岗岩 ;后者富硅、碱 ,高∑REE ,低Ca、Mg、Al,δEu =0 .15～ 0 .2 3,与典型“A”型花岗岩地球化学一致。两种不同成因类型花岗岩是在碰撞造山之后的应力松弛阶段 ,随着拉张程度的不断增强 ,岩浆向着硅。
Although the Haerjiao pluton and Kuoyitasi pluton, which occur in north Sawuer mountain of north of Zhunger terrance in Xinjiang, were formed in early Permian extension environment at the same time, they are abvious different in geochemistry and geology. The former has higher Na 2 O+K 2 O?Zr?Hf and lower Rb?Sr?Ba?Nb?Th?Rb/Sr?Rb/Ba. Its ∑REE ranges between 99.66 and 249.47 and averages 177.08. δEu ranges from 0.66 to 0.77 and averages 0.72. Its geochemistry is similar with that of the Hercynian I-type granites in this region. The latter has higher silicon, alkaline, ∑REE and lower Ca, Mg and Al. Its δ Eu is between 0.15 and 0.23, which is in accord with characteristics of typical A-type granites. We suggest that the two type granites were the products of different periods in the course of extension after the collision orogeny and silicon, alkaline and REE of the magma in crease steadily in the process.
出处
《资源调查与环境》
2002年第3期185-192,共8页
Resources Survey & Environment
