摘要
在扬子陆块西缘的拉拉、小关河-东川、大红山等地区出露了3套古元古代Statherian期(1.6～1.8Ga)的浅变质岩系,被分别命名为河口群、通安组-汤丹群-东川群、大红山群。从2.0Ga至1.4Ga期间,其地质历史演化经历:(1)约2.2～1.8Ga的造山运动;(2)约1.7～1.5Ga发生的非造山裂解事件群;(3)约1.7～1.5Ga侵入到古元古代地层的基性岩墙群、层状侵入体事件;(4)因民、落雪地区,约1.5～1.2Ga发生的陆架裂陷事件;(5)上扬子古陆块西缘,约1.0Ga发生的碰撞造山事件。本文重点阐述了扬子陆块西缘1.8～1.6Ga时期大规模裂解事件群的性质、特点和同位素年龄数据,认为上扬子陆块裂解事件群的性质、特点和时代等特征与华北、北美、西伯利亚和西北欧有很大的相似性,并提出了古元古代扬子陆块与其它陆块曾经联合的证据。
Three suites of epimetamorphic rock series dated at 1.6 - 18 Ga （ Statherian of the Palaeoproterozoic） are cropped out in the Lala, Xiaoguanhe-Dongehuan and Dahongshan areas on the western margin of the Yangtze landmass, named the Hekou Group, Tong＇an Formation-Tangdan Group-Dongchuan Group, and Dahongshan Group, respectively. The evolution of geologic history of the above-mentioned rock series from 2.0 Ga to 1.4 Ga went through： （1） orogenic movements at ca. 2.2 -1.8 Ga; （2） anorogenic splitting event groups at ca. 1.7 - 1.5 Ga; （3） penetrating of basic dike swarms and stratified intrusions into the Palaeoproterozoic strata at ca. 1.7 - 1.5 Ga; （4） shelf rifting events in the Yinmin-Luoxue zone at ca. 1.5 - 1.2 Ga, and （5） collision-orogenic events on the western margin of the upper Yangtze landmass around 1.0 Ga. The emphasis in the present paper focuses on the nature, characteristics and isotopic dating data for the 1.8 - 1.6 Ga pervasive shelf rifting events on the western margin of the Yangtze landmass, which may well be compared with the nature, characteristics and age determinations for North China, North America, Siberia and Northwest Europe, and thus have provided evidences in favour of the unity of the Yangtze landmass with other continental masses during the Palaeoproterozoic.
出处
《沉积与特提斯地质》
CAS
CSCD
2012年第3期31-40,共10页
Sedimentary Geology and Tethyan Geology
基金
国家973项目(编号:2009CB421003)
中国地质调查局地质调查项目(编号:1212010610213
1212011121110)
国家自然科学基金项目(编号:40773001)共同资助的成果
关键词
扬子陆块西缘
哥伦比亚超大陆
古元古代
汇聚与裂解
western margin of the Yangtze landmass
Columbia supercontinent
Palaeoproterozoic
assembly and breakup
