北大别构造带始太古代片麻岩的发现
Discovery of Eoarchean Gneisses in Northern Dabie Belt
邱啸飞 1彭练红 1孔令耀 2邓新 1王达 3陈伟雄 4吴年文 1童喜润 1田洋 1牛志军1
作者信息
- 1. 中国地质调查局武汉地质调查中心,湖北武汉 430205
- 2. 湖北省地质调查研究院,湖北武汉 430074
- 3. 美国卡内基科学研究所,华盛顿20015;成都理工大学,四川成都 610059
- 4. 中国地质调查局武汉地质调查中心,湖北武汉 430205;中国地质大学,湖北武汉 430074
- 折叠
摘要
始太古代岩石因其稀缺性,对于理解最早期陆壳形成和演化具有重要意义.报道了大别造山带北大别构造带内新识别出的一套英云闪长片麻岩和斜长角闪片麻岩组合的锆石年龄,并将其命名为"木子店片麻杂岩".定年结果显示,斜长角闪片岩和英云闪长片麻岩的锆石年龄分别为(3 653±43)Ma和(3 701±29)Ma,为目前扬子克拉通已发现的最古老岩石,说明扬子克拉通之下可能存在极为古老的基底岩石.与崆岭杂岩基底岩石的对比研究显示,木子店片麻杂岩在岩石类型以及时代上与崆岭杂岩均存在明显差异,说明崆岭杂岩和木子店片麻杂岩可能代表了扬子克拉通内相互独立的微陆块古陆核.
Abstract
Eoarchean rocks are of great significance for understanding the formation and evolution of the earliest continental crust due to their scarcity.In this study,it reports zircon U-Pb ages of a newly recognized tonalitic gneiss and plagioclase-amphibolitic gneiss assemblage in the northern Dabie belt,which is named as the"Muzidian gneiss complex".The zircon dating results show that the ages of the plagioclase-amphibolitic schist and tonalitic gneiss in the Muzidian gneiss complex are(3 653±43)Ma and(3 701±29)Ma,respectively,which are the oldest rocks known in the Yangtze craton,indicating ancient basement rocks may exist beneath the craton.A comparative study with the basement rocks of the Kongling complex reveals that both the lithology and age of the Muzidian gneiss complex are distinct from those of the Kongling complex,indicating that they may represent independent microcontinental nucleus of the Yangtze craton.
关键词
始太古代/木子店片麻杂岩/扬子克拉通/北大别构造带/英云闪长片麻岩/构造地质学/岩石学Key words
Eoarchean/Muzidian gneiss complex/Yangtze craton/northern Dabie belt/tonalitic gneiss/tectonics/petrology引用本文复制引用
出版年
2024
NETL
NSTL
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