华北克拉通北缘崇礼—赤城地区的红旗营子(岩)群:一套晚古生代的变质杂岩  

The Hongqiyingzi Group in the Chongli-Chicheng area,northern margin of the North China Craton:A suite of late Paleozoic metamorphic complex

作　　者：王惠初 初航 相振群[1,2] 陆松年[1] 赵凤清 任云伟 

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《地学前缘》2012年第5期100-113,共14页Earth Science Frontiers

基　　金：国家自然科学基金项目(40772120;40902021);国土资源部地质矿产调查评价专项(1212010911005;1212010711815)

摘　　要：分布在华北克拉通北缘中段崇礼—赤城地区的红旗营子(岩)群主要由变质表壳岩、晚古生代的闪长质—石英闪长质片麻岩和古元古代—新太古代的变质岩残片或残块组成。利用SHRIMP和LA-ICPMS法对红旗营子(岩)群变质表壳岩的锆石同位素年代学研究表明,变质表壳岩样品中除大量古元古代—新太古代的锆石年龄信息外,还有许多中元古代—晚古生代的锆石,且均有晚古生代甚至早中生代的多阶段变质作用的记录。这些证据表明红旗营子(岩)群并非早前寒武纪岩石建造,而是一套晚古生代的变质杂岩。红旗营子(岩)群周围侵入体的锆石U-Pb测年表明岩浆作用与变质作用具有较好的相关性,它们与中亚造山带多阶段的俯冲、碰撞造山和后造山伸展事件相关。由于红旗营子杂岩中含有晚古生代退变榴辉岩和变质方辉橄榄岩,这可能意味着华北克拉通北缘的冀北地块在晚古生代早期曾经从华北克拉通上裂开,在中亚造山带古亚洲洋板块俯冲作用的影响下又重新拼合,红旗营子杂岩代表华北克拉通北缘的冀北地块与华北克拉通在晚古生代重新拼合的俯冲碰撞拼贴带。The Hongqiyingzi Group occurred in the Chongli-Chicheng area,northern margin of the North China craton,was composed of metamorphic supracrustal rocks,Late Paleozoic dioritic-quartz-dioritic gneisses and the remnants of Paleoproterozoic-Neoarchean rocks.The SHRIMP and LA-ICPMS zircon U-Pb dating for the Hongqiyingzi metamorphic supracrustal rocks shows that the samples not only contain a large number of the zircon reflecting the Paleoproterozoic-Neoarchean and Mesoproterozoic-Late Paleozoic age information,but also record multiple metamorphic events during the late Paleozoic-Early Mesozoic.The zircon dating result reveals that the Hongqiyingzi Group wasn＇t formed in the Paleoproterozoic,but a suite of Late Paleozoic metamorphic complex.The zircon U-Pb dating for the plutons distributed in the surrounding of the Hongqiyingzi Group indicated the correlation between the Late Paleozoic-Early Mesozoic magmatism and metamorphism,which are related with the multi-stage subduction-syn-orogenic-post-orogenic events of Central Asian Orogenic Belt.Because the Hongqiyingzi complex contains some Late Paleozoic retrograde eclogites and the metamorphic peridotites（harzburgite） occurring as lenticular enclave in highly deformed gneisses,this may mean that the Northern Hebei Block had separated from the North China Craton in the early stage of the late Paleozoic,and re-amalgamated accompanied by the Central Asian Orogene.The Hongqiyingzi complex represent the subduction-collision amalgamating zone between the Nothern Hebei Block and the North China Craton during the late Paleozoic.

关 键 词：崇礼—赤城地区 红旗营子(岩)群 锆石U-PB测年 晚古生代 变质杂岩 

分 类 号：P588.3[天文地球—岩石学]