CAJ | 학술논문

近些年来，燕山地区青白口系下马岭组斑脱岩锆石SHRIMP法U-Pb测年获1366～1380 Ma,下马岭组的时代已属中元古代。华北地台南缘苏-鲁-皖地区与下马岭组相当的地层当属徐淮群上部史家组至望山组，也有属中元古代的可能。淮北地区出露大面积的基性岩墙群，并侵入于徐淮群中,辉绿岩单颗粒锆石SHRIMP法U-Pb年龄为976土24～1038土26 Ma，徐淮群的时代显然老于该年龄。据此，苏-鲁-皖地区“青白口系至震旦系”的地层格架应重新进行划分与对比。结合宏观藻类化石Chuaria-Tawuia组合与蠕形类化石Pararenicola-Paleolina组合等资料，笔者将本区原“青白口系至震旦系”的地层重新划分为中元界长城系-蓟县系的徐淮群下部,金州系的徐淮群上部,新元古界下部的淮南群和新元古界上部的南华系。本区凤台组冰碛岩与劳伦古陆西缘750 Ma的拉皮坦群冰碛层似可对比；与五岗集组相当的陕西罗圈组上段泥质岩Rb-Sr年龄为722 Ma；凤台组冰碛层出现古磁极倒转，与扬子地台也有磁极倒转的古城组冰碛层大体相当，围干组-凤台组-五岗集组分别可与扬子地台的莲沱组-古城组-大塘坡组对比，其时代应划归南华纪为宜。据此，笔者全面调整了苏-鲁-皖区中-新元古界的划分与对比，并首次将华北地台南缘的冰碛层划归南华系下部，实现了华北地台与扬子地台南华系的直接对比与衔接，初步解决了华北地台与扬子地台南华系-震旦系长期悬而未决的重大地层对比问题，为重新建立我国以蓟县剖面为代表的中-新元古界地层格架提供了坚实的地层基础，此建议无疑具有重要的地层学意义和地质年代学意义。另外，该区新元古界亦可与劳伦古陆加拿大新元古界麦肯齐山超群-铜旋回和拉皮坦群冰碛层对比，进一步表明华北地台与劳伦古陆曾处在Rodinia超大陆范围内的可能。近些年來，燕山地區青白口繫下馬嶺組斑脫巖鋯石SHRIMP法U-Pb測年穫1366～1380 Ma,下馬嶺組的時代已屬中元古代。華北地檯南緣囌-魯-皖地區與下馬嶺組相噹的地層噹屬徐淮群上部史傢組至望山組，也有屬中元古代的可能。淮北地區齣露大麵積的基性巖牆群，併侵入于徐淮群中,輝綠巖單顆粒鋯石SHRIMP法U-Pb年齡為976土24～1038土26 Ma，徐淮群的時代顯然老于該年齡。據此，囌-魯-皖地區“青白口繫至震旦繫”的地層格架應重新進行劃分與對比。結閤宏觀藻類化石Chuaria-Tawuia組閤與蠕形類化石Pararenicola-Paleolina組閤等資料，筆者將本區原“青白口繫至震旦繫”的地層重新劃分為中元界長城繫-薊縣繫的徐淮群下部,金州繫的徐淮群上部,新元古界下部的淮南群和新元古界上部的南華繫。本區鳳檯組冰磧巖與勞倫古陸西緣750 Ma的拉皮坦群冰磧層似可對比；與五崗集組相噹的陝西囉圈組上段泥質巖Rb-Sr年齡為722 Ma；鳳檯組冰磧層齣現古磁極倒轉，與颺子地檯也有磁極倒轉的古城組冰磧層大體相噹，圍榦組-鳳檯組-五崗集組分彆可與颺子地檯的蓮沱組-古城組-大塘坡組對比，其時代應劃歸南華紀為宜。據此，筆者全麵調整瞭囌-魯-皖區中-新元古界的劃分與對比，併首次將華北地檯南緣的冰磧層劃歸南華繫下部，實現瞭華北地檯與颺子地檯南華繫的直接對比與銜接，初步解決瞭華北地檯與颺子地檯南華繫-震旦繫長期懸而未決的重大地層對比問題，為重新建立我國以薊縣剖麵為代錶的中-新元古界地層格架提供瞭堅實的地層基礎，此建議無疑具有重要的地層學意義和地質年代學意義。另外，該區新元古界亦可與勞倫古陸加拿大新元古界麥肯齊山超群-銅鏇迴和拉皮坦群冰磧層對比，進一步錶明華北地檯與勞倫古陸曾處在Rodinia超大陸範圍內的可能。
근사년래，연산지구청백구계하마령조반탈암고석SHRIMP법U-Pb측년획1366～1380 Ma,하마령조적시대이속중원고대。화북지태남연소-로-환지구여하마령조상당적지층당속서회군상부사가조지망산조，야유속중원고대적가능。회북지구출로대면적적기성암장군，병침입우서회군중,휘록암단과립고석SHRIMP법U-Pb년령위976토24～1038토26 Ma，서회군적시대현연로우해년령。거차，소-로-환지구“청백구계지진단계”적지층격가응중신진행화분여대비。결합굉관조류화석Chuaria-Tawuia조합여연형류화석Pararenicola-Paleolina조합등자료，필자장본구원“청백구계지진단계”적지층중신화분위중원계장성계-계현계적서회군하부,금주계적서회군상부,신원고계하부적회남군화신원고계상부적남화계。본구봉태조빙적암여로륜고륙서연750 Ma적랍피탄군빙적층사가대비；여오강집조상당적협서라권조상단니질암Rb-Sr년령위722 Ma；봉태조빙적층출현고자겁도전，여양자지태야유자겁도전적고성조빙적층대체상당，위간조-봉태조-오강집조분별가여양자지태적련타조-고성조-대당파조대비，기시대응화귀남화기위의。거차，필자전면조정료소-로-환구중-신원고계적화분여대비，병수차장화북지태남연적빙적층화귀남화계하부，실현료화북지태여양자지태남화계적직접대비여함접，초보해결료화북지태여양자지태남화계-진단계장기현이미결적중대지층대비문제，위중신건립아국이계현부면위대표적중-신원고계지층격가제공료견실적지층기출，차건의무의구유중요적지층학의의화지질년대학의의。령외，해구신원고계역가여로륜고륙가나대신원고계맥긍제산초군-동선회화랍피탄군빙적층대비，진일보표명화북지태여로륜고륙증처재Rodinia초대륙범위내적가능。
The Late Precambrian strata of Su-Lu-Wan(Jiangsu-Shandong-Anhui Provine) area is divided from lower to upper into the Huainan Group,Xuhuai Group and Suxian Group in Southern margin of North China Block. It is the Neoproterozoic Era in age. According to the stromatolites Linella-Gymnosolen-Katavia assem-blage and present reported new U-Pb ages (SHRIPM), the Shijia Formation and Wangshan Formation of the up-per part of the Xuhuai Group may be correlated with Xiamaling Formation with a weighted mean 206Pb/U238 of 1368~1370 Ma in Yanshan Mountain area,northern China. Therefor, the Shijia Formation and Wangshan Forma-tion is of Late Mesoproterozoic Era in age. The lower part of Xuhuai Group with the stromatolites Conophy-ton-Baicaliaassemblage may be correlated with Luda Group and Gezhenpu Group in Southern Liaodong Peni-sula, Liaoning Province, China. So, it is Early-Middle Mesoproterozoic in age. Further SHRIMP U-Pb dates of 976土24 Ma(206Pb/238U) and 1038土26 Ma(207Pb/206Pb) were gained from the diabase rock in the Neoproterozoic strata in the Xu-Huai area, which indicates the origin of the Neoproterozoic magma and it is also proved that there was a great scale basic magmatic active developed in the southeastern margin of the North China Block, which can be correlated with the intrusive magma events of the Grenvillian orogenic episode in Northern Ameri-can, Mid-Africa and Easthern Greenland. So, Xuhuai Group and Suxian Group is the Neop-roterozoic Era in age in the southern margin of Northern China Block. Neoproterozoic strata is divided into Huainan Group of the low-er part of Neoproterozoic and Nanhua System of the upper part of Neoproterozoic in Su-Lu-Wan district, south-ern margin of Northern China continent. Huainan Group is divided from lower to upper into Caodian(曹店) For-mation, Bagongshan Formation, Liulaobei Formation, Shouxian Formation, Jiuliqiao Formation and Sidingshan Formation. It is of the early Neoproterozoic in age. Nanhua System is divided into Weigan Formation, Fengtai Formation and Wugangji Formation. Weigan Formation and Wugangji Formation are the normal marine facies de-posit. Fengtai Formation is recognized as the tillite of Neoproterozoic glaciations. Weigan Formation, Fengtai For-mation and Wugangji Formation can respectively correlate with Lantuo Formation,Gucheng Formation and Datangpo Formation in Yangze Block, South China. They are of the Late Neoproterozoic in age.