摘要
华北克拉通上存在广泛的古元古代地质记录,尤其是构造岩石组合和同位素年龄资料,显示克拉通上可能存在多条古元古代的汇聚拼合带:如鄂尔多斯地块与华北东部-阴山地块之间的拼合造山带、华北东部地块与狼林地块之间的胶辽造山带以及华北克拉通北缘的安第斯型汇聚边界等.华北克拉通中部地区的古元古代锆石年龄数据统计,显示出2.3～2.4 Ga、2.0～2.2 Ga和1.8～1.95 Ga三组年龄值,暗示华北克拉通古元古代可能存在两个演化阶段:其中古元古代末期(1.8～1.95 Ga)的造山事件已得到了广泛认可,并认为与全球Columbia超大陆汇聚事件相关;而2.3～2.4 Ga、2.00～2.2 Ga所代表的构造热事件的性质和意义尚不明确.我国古元古代末期有关陆块汇聚的构造热事件以及其后的裂解事件群和地层学记录,与新的国际前寒武纪地质年代表建议的古-中元古代界线一致,这将促进我国特别是古中元古代的前寒武纪研究.
The Paleoproterozoic geological events were widely recorded on the North China Craton. The characteristic of petrotectonic assemblages and U-Pb age informations indicate that several Paleoproterozoic amalgamative / convergent zones probably existed in the North China Craton： the circumjacent Ordos orogenic belt between the Ordos Block and the Eastern Yinshan Block, the Jia- oliao orogenic belt between Eastern Yinshan Block and Langlin Block, and the Andean-style convergent belt on the northern margin of the North China Craton. The Paleoproterozoic age information from the central part of the North China Craton reveals three groups of age peak value： 2.3-2.4 Ga, 2.0-2.2 Ga, and 1.8-1.95 Ga, which imply two stages of evolution in Paleoproterozoic. The late Paleoproterozoic orogenic event （1.8-1.95 Ga） was widely accepted, but the character and implication of the thermo-tectonic events represented by other two groups of age are amphibolous. The terminal Paleoproterozoic continental block amalgamation, the subsequent rifting events and stratigraphic records on the North China Craton are consistent with the boundary between Paleoproterozoic and Mesoproterozoic proposed by the “special reference” to Precambrian, which will promote research of the Precambrian, especially the Paleo-Mesoproterozoic in China.
出处
《地质调查与研究》
2005年第3期129-143,共15页
Geological Survey and Research
基金
中国地质调查局综合研究项目(1212010510512)
