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北淮阳构造带为一条沿大别造山带北麓展布的狭长构造带,是华北板块与扬子板块碰撞造山的产物,其物源组成、构造属性等研究内容是揭示南北板块在中国东部的大地构造单元格局以及时空演化的关键信息。结合构造变形、岩石学、岩石地球化学、锆石U-Pb年代学等方法对北淮阳前中生代岩石地层单元苏家河群/卢镇关群和信阳群/佛子岭群进行对比分析,就其构造属性形成这样的基本认识:北淮阳构造带是杨子板块向华北板块俯冲-碰撞的结合带,其物质组成具有双源性-主体部分来源于杨子板块,由代表了杨子板块北缘基底的晚元古代苏家河群(784±19Ma)/卢镇关群(756±12Ma)和杨子板块被动陆缘复理石沉积建造-中泥盆世至晚泥盆世早期的信阳群南湾组组成,后者相当于商丹缝合带以南的刘岭群;信阳群龟山组亲缘于华北板块并构成华北板块南缘的弧前楔形沉积体,是沿商丹缝合带分布的桃花铺弧前楔形沉积体的东延。佛子岭群总体可与信阳群相连,全岩成分显示,佛子岭群沉积构造环境既有活动大陆边缘,又有被动大陆边缘。由于中生代以来多期构造变形叠加(至少三期),佛子岭群岩石地层单元的叠置关系被改造或重置,使其缺少“构造解体”的证据,而无法在构造单元上细分。对于两大板块之间的缝合带位置,笔者认为:商丹缝合带进入北淮阳构造带后,应沿着北淮阳的北界,与龟山-梅山-六安-磨墩水库一线延伸的断裂带相连。
The North Huaiyang tectonic belt is a narrow structural belt distributed along the northern foot of the Dabie orogenic belt. It is the product of the collision between the North China Plate and the Yangtze Plate, and its provenance composition, tectonic attribute and other research contents reveal that the North-South plate in the eastern part of China The tectonic unit structure of the earth and the key information of the evolution of space-time. Based on the analysis of tectonic deformation, petrology, lithochemistry and zircon U-Pb chronology, the authors compared and analyzed the Mesozoic stratigraphic units Sujiahe Group / Luzhenuan Group and Xinyang Group / The tectonic attributes form the basic understanding that the Beihuaiyang tectonic belt is the subduction-collision zone of the Yangzi plate to the North China plate, and its material composition is dual-sourced - the main part is derived from the Yangzi plate and represented by the Yangzi plate north The Late Proterozoic Sujiahe Group (784 ± 19Ma) / Luzeng Group (756 ± 12Ma) and the Yangzi plate of the margin basaltic sediments were deposited from the Late Cretaceous to the Xinyang Qunnan Bay Formation, which is equivalent to Liuling Group south of Shangdan suture zone. The Xifeng Group Kameishan Formation is associated with the North China plate and forms an anterior-arc wedge depositional body along the southern margin of the North China Plate. East extension of pre-wedge deposits. The Foziling Group can be connected with the Xinyang Group as a whole. The whole rock composition shows that the Faziling Group sedimentary tectonic environment has both active continental margins and passive continental margins. Due to the multi-stage tectonic deformation superimposition (at least three stages) since the Mesozoic era, the superimposition relationship of the units of the Foziling Group in the rock strata has been altered or reset so that it lacks evidence of “structural disintegration” and can not be thinned in the tectonic units Minute. For the location of the suture between the two plates, I believe that Shangdan suture should extend along the northern boundary of North Huaiyang and the north of Gui-Shan-Meishan-Lu’an-Mudun Reservoir Of the fault zone.