摘要
本文概括性地阐述我国前寒武纪冥古宙、太古宙、元古宙三大地史阶段的重大地质事件,粗略勾绘前寒武纪地球演化的轨迹,期望了解我国与全球变化的异同,进一步突出我国前寒武纪三大地史阶段中新太古代超级地质事件及元古宙时期中国大陆块体对哥伦比亚及罗迪尼亚两个超大陆形成与破裂的地质响应。冥古宙是地球最早期的地史阶段,从太阳系形成的4 567Ma至地球上最老的4 030Ma的Acasta片麻杂岩。碎屑锆石保存最好的地点是西澳的Mt.Narryer和Jack Hills。目前在中国大陆至少有7个地点发现具有罕见的约4.0Ga的碎屑锆石,这些地点并不位于克拉通区,而是赋存于造山系新元古代至古生代以碎屑岩为主的地层中。太古宙（4 030～2 420Ma）定义为从最古老的岩石出现（4 030Ma Acasta片麻岩）至冰碛层首次广泛分布的寒冷期之间的一段地史。最古老的岩石为英云闪长片麻岩,构成加拿大西北斯拉夫克拉通4.03～3.94Ga Acasta片麻岩的一部分。西南格陵兰Isua带保存全球有最老的表壳岩,形成于3 810 Ma。太古宙最重大的地质事件莫过于2 780～2 420 Ma时期的新太古代超级事件。值得指出的是华北克拉通最古老、也是中国最古老的岩石出露在中国辽宁鞍山地区,约3.80Ga英云闪长岩-奧长花岗质片麻岩和3.30Ga的表壳岩已被识别。华北克拉通太古宙有与世界各地太古宙相似的演化历史和特点,包括花岗岩-绿岩带及高级变质片麻岩带、广泛的英云闪长岩-奧长花岗岩-花岗闪长岩（TTG）片麻岩、古陆壳的出露（略老于3.8Ga）、广泛分布的BIF等。我国太古宙花岗岩-绿岩带虽然在华北克拉通分布较广,但与南非、格陵兰、加拿大、西澳等地经典的花岗岩-绿岩带相比,时代偏新,仅以新太古代为主,规模偏小,缺少大面积分布的科马提岩,且变质程度偏高,主要为角闪岩相-麻粒岩相变质。演化到
The major geological events during the three Precambrian Eons of the Earth history,i.e.,the Hadean,the Archean and the Proterozoic,are summarily described and the Precambrian evolution nature of China continent is roughly depicted.It is desirable to understand the similarity and difference between China and the global,and it is a further highlight of China continent Neoarchean super geological event,and response to the formation and breakup of the Proterozoic Colombia and Rodinia Supercontinents.The Hadean Eon for the earliest period of the Earth history extends from the age of formation of the solar system at 4567 Ma,to the age of Earth＇s oldest dated rock from the Acasta Gneiss Complex,at 4030 Ma.The Hadean detrital zircon has been well preserved from Mt.Narryer and the Jack Hills greenstone belt of Western Australia.Meanwhile at present,rare detrital zircons of Hadean age were analyzed from 7places in China,those are located at the Neoproterozoic to Paleozoic orogens,not in the cratons.The Archean Eon can be defined as the time of Precambrian history from the first appearance of preserved rocks at the Earth＇s surface（4030 Ma Acasta Gneiss）,to the first appearance of widespread glacial rocks,cooler Earth conditions.The oldest dated rock on Earth is a tonalitic gneiss that forms part of the 4.03-3.94 Ga Acasta gneiss of the northwestern Canada Slave Craton.Supracrustal rocks are locally well preserved in the Isua supracrustal belt in southwestern Greenland.It is worth to point out that the most important event of Archean is the super geological event between 2780 Ma to 2420 Ma.The oldest rocks of the North China Craton（NCC）and also of China are exposed at the Anshan region of Liaoning Province,where about 3.8Ga tonalite-trondhjemite gneiss and 3.3Ga supracrustal rocks are recognized.Archean evolution and nature of NCC are quite similar to that of cratons in the world,such as the granite-greenstone belt and high-grade gneiss,tonalite-trondhjemite-granadiritesuite（TTG）,older continent crust（a lit
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2016年第6期140-155,共16页
Earth Science Frontiers
基金
科学技术部科技基础性工作专项(2015FY310100-3)
中国地质调查局项目(12120114001301,12120114021701)
关键词
前寒武纪
三大地史阶段
地质事件
Precambrian
three eons of the Earth history
geological events
