华北陆块对Rodinia超大陆的响应及其特征  

Response of North China Block to Rodinia supercontinent and its characteristics

作　　者：彭澎[1] 刘文军[1] 翟明国[1] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029

出　　处：《岩石矿物学杂志》2002年第4期343-355,共13页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金资助项目(4 0 0 72 0 6 1);中国科学院重大创新资助项目(KZCXI- 0 7)

摘　　要：研究揭示华北陆块 130 0～ 10 0 0Ma和 80 0～ 6 5 0Ma都存在比较弱的岩浆 -变质事件,它们可能对应于华南陆块的碰撞(四堡运动)和裂解事件。华北陆块的四堡期蛇绿混杂岩可能只见于新元古代秦岭造山带中。秦岭造山带北缘识别出了一些花岗质侵入体,它们具有碰撞或碰撞后花岗岩的特征。华北陆块北缘的火山沉积岩系不具有离散边界杂岩的特征,它们可能揭示了大陆边缘或者大陆伸展过程。华北陆块与 80 0～ 6 5 0Ma事件相关的岩石主要为来自富集地幔的基性岩墙和来自陆内裂谷的沉积岩,它们很可能与Rodinia裂解有关。沉积学和古生物学特征表明元古宙华北陆块不同于华南陆块,而与西伯利亚陆块相似。据此可以认为华北陆块是Rodinia超大陆的一部分,它位于超大陆的边缘,可能不与华南陆块紧邻,而与西伯利亚陆块较近。Recent studies reveal records of weak metamorphic-magmatic events of 1?300～ 1?000 Ma and 800～650 Ma in the North China Block (NCB), which probably correspond to collision events (Sibao orogenic event) and breakup events in the South China Block(SCB). The Sibao_age ophiolitic complex in NCB is represented only by Neoproterozoic North Qinling orogenic belt. Some granitic intrusive rocks were recognized along the North Qinling belt, which demonstrate properties of collisional and post_collisional granites. There are some volcanic_sedimentary rocks distributed along the northern margin of NCB, most of which do not show characteristics of the complex in the divergent margin, but probably reflect extensional process of the continent and continental margin. The rocks of 800～650 Ma are mainly basic dikes in the enriched mantle and sedimentary successions in continental rift, most likely related to the breakup of Rodinian supercontinent. The characteristics of sedimentology and palaeontol_ ogy suggest that NCB was quite different from SCB in Proterozoic, but similar to the Siberia block. Based on the above discussion, the authors hold that, being a part of Rodinia supercontinent and located at its edge, NCB seems not to connect with the SCB but is quite close to the Siberia block.

关 键 词：华北陆块 Grenville造山运动 RODINIA超大陆 岩浆 裂解事件 碰撞事件 沉积学 古生物学 

分 类 号：P542[天文地球—构造地质学]