北淮阳构造带的属性及其对板块缝合线位置的启示

发布时间：2018-07-27 11:52

【摘要】：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。
[Abstract]:The northern Huaiyang tectonic belt is a long narrow tectonic belt along the northern foot of the Dabie orogenic belt. It is the product of the collision orogeny of the North China plate and the Yangtze plate. Its source composition and structural properties are the key information of the tectonic units of the north and South plates in eastern China and the key information of spatiotemporal evolution. Lithogeochemistry, zircon U-Pb chronology and other methods have made a comparative analysis of the pre Mesozoic lithostratigraphic units of the Sujia River group / Luzhen Guan group and the Xinyang group / fuchling group in northern Huaiyang. The basic understanding of its structural properties is that the northern Huaiyang tectonic zone is the joint zone of the subduction and collision of the Yang Zi plate to the North plate block. The dual source - main body is derived from the Yang Zi plate, which is composed of the late Proterozoic Sujia River group (784 + 19Ma) / Luzhen Guan group (756 + 12Ma) and the Yang Zi plate passive continental margin sedimentary formation, which represents the northern margin of the Yang Zi plate - the southern Xinyang group of the Middle Devonian to the early Late Devonian group, which is equivalent to Liu Ling in the south of the Shang Dan suture belt. The Xinyang group is closely related to the North China plate and forms a pre arc wedge-shaped sedimentary body in the southern margin of the North China plate. It is the East extension of the wedge-shaped sedimentary body of the peach flower spread along the Shang Dan suture zone. The fqiging group is generally connected with the Xinyang group. The whole rock composition shows that the sedimentary environment of the fqiging group has both active continental margin and passive continent. Due to the superposition of multistage tectonic deformation (at least three periods) since Mesozoic, the stacking relationship of the lithostratigraphic units of the Fuzi Ridge Group is reformed or reset, which makes it lack the evidence of "tectonic disintegration", but can not be subdivided on the tectonic units. For the suture zone between the two plates, the author believes that the Shang Dan suture belt enters the northern Huaiyang tectonic belt. It should be connected along the northern boundary of northern Huaiyang with the fault zone extending along the first line of the Gui Shan Meishan Lu'an moutun reservoir.
【作者单位】：合肥工业大学资源与环境工程学院;加拿大滑铁卢大学;河南省地质调查院;
【基金】：国家自然科学基金资助项目(编号:41072161、41272222) 中国地质调查局科研项目(编号:121201121114、201201044002)的成果
【分类号】：P542

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