【摘要】 古元古代是华北克拉通构造演化的关键时期,主要体现在由新太古代大陆地壳垂向增生到古元古代侧向增生的转换。华北中部构造带的构造性质是近年来华北克拉通构造演化研究争论的焦点之一,构造带中段出露恒山、五台和阜平等多个前寒武纪变质杂岩,其中发育多条大型韧性剪切带,这些剪切带的主期活动时代均为1. 85～1. 80Ga。本文以这些剪切带为构造边界将变质杂岩划分为恒山地块、繁峙地块、五台地块和阜平地块,并在早期研究中解析了繁峙地块构造挤入事件和阜平地块西部的伸展构造事件,表明这些前寒武纪地块的构造位置在古元古代末前后可能有所不同。结合前人资料,本文对这些地块的岩石组成、形成时代、变质作用以及典型构造样式等特征进行详细对比研究。结果表明,恒山地块、阜平地块和五台地块共同组成华北克拉通早前寒武纪"高级区-绿岩带"的典型壳层结构,而繁峙地块与其他地块具有明显差异,具有外来地块特征。更多还原

【Abstract】 The Paleoproterozoic is the key period in the tectonic evolution of the North China Craton,which is mainly showed by the transformation from the vertical accretionary of the continent crust in Neoarchean to the lateral growth in Paleoproterozoic. One of these key controversies on the tectonic evolution of the North China Craton( NCC) in recent years is the tectonic property of Trans-North China Orogen( TNCO),represented by two main ideas which the TNCO should be a collisional orogenic belt or an active belt with several Early Paleoproterozoic rifts. A series of Precambrian metamorphic complexes,including Hengshan complex,Wutai complex,and Fuping complex,have been exposed in the central part of the TNCO. These metamorphic complexes have been considered as the middle and lower crustal material composition and continental marginal sedimentary combination of NCC. A number of large-scale ductile shear zones are developed among these complexes,and the age of these shear zones are mainly concentrated on 1. 85 ～ 1. 80 Ga.According to the previous research,the author have re-divided these complexes into the Hengshan Block,the Fanshi Block,the Wutai Block and the Fuping Block based on these Paleoproterozoic ductile shear zones as tectonic boundaries of blocks,and we analyzed the tectonic indention of the Fanshi Block and the uplift and extensional event in the Fuping Block in the previous study,indicating that a series of tectonic events developed in TNCO during Late Paleoproterozoic and the tectonic position of these Precambrian blocks are different before these events. This paper has showed a detailed comparative study on the petrology,geochronology,metamorphism and tectonic framework of these blocks. The results show that the Hengshan Block,the Fuping Block and the Wutai Block constitute the typical construction of continental crust of the NCC together,which named by "the high grade region-greenstone belt". While the Fanshi Block shows different characteristics from other blocks and characteristics of an exotic terrane,which might confirm the tectonic indention constrained by the kinematics of the Zhujiafang and Wangjiahui ductile shear zones. The Longquanguan extensional ductile shear zone might indicate the rapid uplift of the Fuping Block and the top-to-the-NW extension of the Wutai Block.更多还原