摘要
本文对清水泉复式杂岩体进行SHRIMP锆石U-Pb测年,获得二长花岗岩形成时代为314.4±4.7 Ma,含黑云母花岗岩形成时代为311.7±4.1 Ma,英云闪长岩形成时代为314.0±4.0 Ma,加之前人在该地区花岗闪长岩中获得Rb-Sr全岩等时线年龄(277.71±13.5 Ma),限定清水泉复式杂岩体的主要侵位时代为晚石炭世至早二叠世,且至少存在两期岩浆;清水泉复式杂岩体微量元素与稀土元素特征表明岩体具有地壳重熔型花岗岩特征,为I型与A型过渡岩浆,形成于活动陆缘的后造山/火山弧环境,从而揭示在晚石炭世时,古红石山洋消减碰撞,之后进入后造山阶段。
On the formation of qingshuiquan compound complex rock mass times and study of the genesis and tectonic environment, reflecting the north belt of beishan of tectonic evolution, therefore pays attention by scholars, in this paper, the compound of mixed rock water springs in SHRIMP zircon U-Pb dating, obtain monzonitic granite formation age was 314.4±4.7 Ma, including biotite granite formation age was 311.7±4.1 Ma, tonalite formation age was 314.0±.0 Ma, combined with previous granodiorite in Rb in the region-the Sr whole rock isochron age （277.71±13.5 Ma）, qualified water fountain compound complex rock mass of the emplacement age of late carboniferous to early Permian, and there are at least two magma;qingshuiquan compound complex rock mass characteristics of trace elements and rare earth elements show that rock has the characteristics of crustal remehing type granite, for type I and type A transitional magma, formed in the active continental margin orogenic/after volcanic arc environment, thus revealing, later carboniferous epoch in ancient gong shishan ocean to reduce collision, after after entering orogenic stage.
出处
《甘肃地质》
2017年第1期32-39,共8页
Gansu Geology
