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| 中国最老岩石和锆石 | |
| 引用本文： | 万渝生,刘敦一,董春艳,Nutman A,Wilde SA,王伟,颉颃强,殷小艳,周红英.中国最老岩石和锆石[J].岩石学报,2009,25(8):1793-1807. |
| 作者姓名： | 万渝生 刘敦一 董春艳 Nutman A Wilde SA 王伟 颉颃强 殷小艳 周红英 |
| 作者单位： | 1. 中国地质科学院地质研究所,北京,100037;北京离子探针中心,北京,100037 2. 澳大利亚科汀大学应用地质系,佩斯,6845 3. 中国地科学院,北京,100037 4. 中国地质调查局天津地质矿产研究所,天津,300170 |
| 基金项目： | 国土资源部重点项目，北京离子探针中心基础研究项目资助成果 |
| 摘 要： | 在中国大陆的许多地区都已发现大于3.4Ga的锆石和岩石.鞍山是全球仅有几个存在≥3.8Ga岩石的地区之一.它们以不大的规模存在于白家坟、东山、深沟寺杂岩中,由糜棱岩化奥长花岗岩、条带状奥长花岗岩和变质石英闪长岩组成.近年来,在鞍山地区还发现了许多3.7～3.6Ga岩石和锆石.锆石Hf同位素组成表明鞍山地区在3.8～3.6Ga期间存在周期性的地幔添加和陆壳形成.除鞍山外,在中国许多地区的不同类型岩石中也获得了≥3.4Ga锆石,虽然它们大多数都是碎屑和残余成因.(1)华北克拉通冀东铬云母石英岩中3.85～3.55Ga碎屑锆石:(2)华北克拉通信阳中生代火山岩长英质麻粒岩中3.66Ga岩浆锆石;(3)华南克拉通宜昌地区杨子地块新元古代砂岩中3.80Ga碎屑锆石(一颗);(4)华南克拉通华夏地块新元古代一古生代变质沉积岩中3.76～3.6Ga碎屑锆石;(5)西北地区塔里木地块阿克塔什塔格地区古元古代片麻状花岗岩中3.6Ga残余锆石;(6)西秦岭奥陶纪变质火山岩中4.08Ga捕掳锆石(一颗);(7)西藏普兰地区奥陶纪石英岩中4.1Ga碎屑锆石(一颗,有3.61Ga增生边).一些古老锆石有高达4.1～4.0Ga的Hf同位素模式年龄.在中国,>3.4Ga地壳物质的比例以往被低估了,发现冥古宙和始太古代物质的可能性仍然存在,它们将对中国早期陆壳演化提供新的制约. |
| 关 键 词： | 最古老岩石 最古老锆石 中国早期地壳演化 锆石定年 Hf同位素 |
| 收稿时间： | 2/1/2009 12:00:00 AM |
| 修稿时间： | 5/4/2009 12:00:00 AM |
The oldest rocks and zircons in China |
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| WAN YuSheng,LIU DunYi,DONG ChunYan,Nutman A,Wilde SA,WANG Wei,XIE HangQiang,YIN XiaoYan and ZHOU HongYing.The oldest rocks and zircons in China[J].Acta Petrologica Sinica,2009,25(8):1793-1807. | |
| Authors: | WAN YuSheng LIU DunYi DONG ChunYan Nutman A Wilde SA WANG Wei XIE HangQiang YIN XiaoYan and ZHOU HongYing |
| Institution: | Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;Department of Applied Geology, Curtin University of Technology, GPO Box U1987, Perth 6845, Australia;Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;Chinese Academy of Geological Sciences, Beijing 100037, China;Tianjin Institute of Geology and Mineral Resources, China Geological Survey, Tianjin 300170, China |
| Abstract: | Zircons and rocks older than 3.4Ga have been discovered in many areas of Chinese continent. Anshan City is one of a few areas in the world where≥3.8Ga continental rocks have been identified. They occur in volumetrically small amounts in the Baijiafen, Dongshan and Shengousi complexes and consist of mylonitized trondhjemite, banded trondhjemite and meta-quartz diorite. Many 3.7～3.6Ga rocks and zircons have also been found recently in the Anshan area. The Hf isotopes of the zircons indicate that Anshan mantle addition and continental formation happened episodically from 3.8 to 3.6Ga. Besides Anshan, ≥3.4Ga ages of zircons from different kinds of rocks in many areas of China have also been obtained, although most of them are detrital and inherited in origin. (1) 3.85～3.55Ga detrital zircons from Arehaean fuehsite quartzite in eastern Hebei, North China Craton (NCC); (2) 3.66Ga magmatic zircons from felsic granulite xenoliths in Mesozoic voleanic rocks in Xinyang, NCC; (3) 3.80Ga detrital zircon (one grain) from Neoproterozoic sandstone in Yichang of the Yangtze Block, South China Craton (SCC); (4) 3.76～3.6Ga detrital zircons from Neoproterozoie-Palaeozoic meta-sedimentary rocks in the Cathaysia Block, SCC; (5) 3.6Ga inherited zircons from a Palaeoproterozoic gneissic granite in the Aketashtage area, Tarim Block, Northwest of China. (6) A grain of 4.08Ga old zircon captured by an Ordovician meta-volcanic rock in Zhangjiazhuang, West of northern Qinling orogen; (7) One 4. 1 Ga detrital zircon (with 3.61 Ga rim) from an Ordovician quartzite in Pulan, Tibet. Some of the ancient zircons have Hf isotope model ages as old as 4.1～4.0Ga. The proportion of>3.4Ga crustal materials in China has been underestimated and there are new possibilities for finding Hadean and Eoarchean materials to constrain early terrestrial evolution. |
| Keywords: | Oldest rocks Oldest zircons Early crustal evolution in China Zircon dating Hf isotope |
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