【作者】 陈志勇；

【导师】 宋鸿林；

【作者基本信息】 中国地质大学（北京） ， 构造地质， 2005， 博士

【摘要】 渣尔泰山群长城系(书记沟组、增隆昌组)、白云鄂博群长城系(都拉哈拉组、尖山组)为同一被动陆缘沉积,前者近陆,后者近洋。长城系与下伏古元古代及其以前基底岩系界面附近之韧性剪切变形特征相同,是长城系相对于下伏岩系向北伸展拆离所致。拆离时间为长城纪末,形成于低温低压环境。长城纪末的区域性伸展作用,导致基底岩系上隆,造成区域性隆升并遭受风化剥蚀,形成长城系增隆昌组顶部、尖山组顶部Ⅰ型不整合界面。在区域性伸展隆升机制下,蓟县纪白云鄂博、渣尔泰山开始分为南北两个相对独立的但中间有海水相连的裂谷型沉积盆地。裂谷作用初期有粗粒碎屑岩—砾岩、含砾砂岩沉积以及基性岩—玄武岩、辉绿岩脉贯入;中期细碎屑沉积—含炭质、粉砂质板岩、粉砂岩、炭质灰岩,粗面质火山岩以及碳酸岩(H8)喷出,辉长岩、蛇纹化橄榄岩、钾长花岗岩等侵入。比鲁特蛇纹岩是裂谷作用中侵位于比鲁特组的超基性岩。同为蓟县纪裂谷沉积的白云鄂博群哈拉霍疙特组、比鲁特组和渣尔泰山群阿古鲁沟组从岩石组合上不能进行对比,白云鄂博铁、稀有稀土矿床含矿围岩既不能与白云鄂博群哈拉霍疙特组进行对比,也不能与尖山组进行对比,它们是白云鄂博裂谷独特的沉积组合。蓟县纪末区域挤压抬升,形成蓟县系顶部(阿古鲁沟组、比鲁特组)古风化壳,造成蓟县系与青白口系之间的平行不整合或微角度不整合。青白口纪早期为被动陆缘沉积(白音布拉格组),晚期转为活动陆缘沉积(呼吉尔特组)并有花岗岩侵入,但中新元古代不存在大规模造山运动。早-中奥陶世包尔汗图群和相伴的花岗岩是华北陆块北缘弧后盆地沉积和同造山岩浆弧花岗岩,代表华北陆块北缘早古生代陆缘增生。上志留统西别河组不整合于其上,标志着中加里东运动的结束。燕山期该地质体推覆于华北陆块之上,其与周边地质体均为断层接触。“槽台”断裂是一北倾逆冲断层,兼具右行走滑之特点。华北陆块北缘“鳄鱼嘴式”结构,由断面北倾的燕山期逆冲断层与断面南倾的中生代盆地边界断裂构成。原1∶20 万区调所划上石炭统本巴图组实为二叠纪蛇绿构造混杂岩带。岩块由下泥盆统火山岩(398±18Ma)、早泥盆世蛇绿岩(385.6±17Ma)、上石炭统本巴图组硬砂岩、灰岩(含蜓化石)以及二叠纪蛇绿岩、玄武岩(285Ma±11Ma)、英云闪长岩(252.17Ma)等组成。基质为粉砂岩、粉砂质板岩夹放射虫硅质岩,其中放射虫硅质岩的形成时代为早—中二叠世。该蛇绿构造混杂岩带与哲斯组前陆盆地磨拉石堆积,早、中二叠世大石寨组陆缘岛弧火山岩共同组成了该区晚古生代陆间造山带。索伦山—查干哈达音蛇绿构造混杂岩带为南戈壁微陆块与华北陆块的缝合带,缝合时间为中二叠世早期。更多还原

【Abstract】 The Changcheng System of Zhaertaishan Group (Shujigou and Zenglongchang Formation) and Baiyunebo Group (Dulahala and Jianshan Formation) were the sediments of a pasive continental margin. The former is near the main land, and the latter is near the ocean. The characteristics of the ductile-shearing deformation developed between the basal rock system (Neoarchaeozoic-Seertengshan Group Complex,and Neoarchaeozoic-Paleoprozoic gneissic granitoids) and the Changcheng System (Dulahala,Jianshan, Shujigou,Zenglongchang Formations ) are identical. The tectonic background of the ductile-shearing deformation is the extensional detachment of the Changcheng System. The deformation environment belongs to lower temperature-pressure one,and the age when the ductile-shearing deformation began is the end of the Changcheng period. Extensional detachment in the end of the Changcheng System resulted in rising of the basal rock system, and the “I”type unconformity on the top of Zhenglongchang, Jianshan Formation were formed as the weathering and eroding in the later. In the Jixian System, two relative independent rifting basin that be connected by the water began to form on the background of the regional extension and upwarping in Baiyunebo (located in the north )and Zhaertaishan ( located in the south ) area. On the initial stage of the rifting, the sediments were mainly coarse clastic rocks include conglomerates and sandstones, and the basic rocks—basalts and dolerites intruded at the same time. On the middle stage of the rifting, the sediments were thin clastic rocks that include carbonaceous silty slates, siltstone and carbonaceous limestone, and the trachy volcanic rocks and carbonatite(sH8)erupted, and the gabbros, serpentinized peridotites and syenogranites intruded. The Bilute serpentinites were ultrabasic rocks that intruded into Bilute Formation during the rifting. Rock assemblages of Halahuogete and Bilute Formation belonging to Baiyunebo Group can not compared with those of Agulugou Formation of Zhaertaishan Group. The country rocks of Baiyunebo Fe-REE deposit were particular sedimentary assemblages of the Baiyunebo Rift, and could not compare with the rocks of Halahuogete and Jianshan Formation. In the end of the Jixian System, The acient weathered crust had been formed on the top of the Jixian System (the top of Agulugou and Bilute Formation) as the rising in this region,which resulted the parallel or tiny-angular unconformity between the Jixian System and the Qingbaikou System. Baiyinbulage Formation formed in the early Qingbaikou System is the sediment of the passive continental margin. In the later Qingbaikou System, Hujierte Formation was formed on the active continental margin, and the granites intruded. There were no large-scale orogenic movements in the middle and upper Proterozoic. Baoerhantu Group is the sediment of the back-arc basin, and the intrusive rocks companied with更多还原