2.1-1.85 Ga tectonic events in the Yangtze Block, South China: Petrological and geochronological evidence from the Kongling Complex and implications for the reconstruction of supercontinent Columbia
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- 作者：Changqing Yin ; Shoufa Lin ; Donald W. Davis ; Guochun Zhao ; Wenjiao Xiao ; Longming Li ; Yanhong He
- 关键词：High-pressure metamorphism ; U&ndash ; Pb age ; Palaeoproterozoic ; Kongling Complex ; South China ; Columbia supercontinent
- 刊名：Lithos
- 出版年：December, 2013
- 年：2013
- 卷：182-183
- 期：Complete
- 页码：200-210
- 全文大小：2133 K
文摘
This paper presents petrography, zircon U-Pb ages and Hf isotopic data as well as whole-rock Sm-Nd isotopic data for mafic granulites, metapelitic rocks and high-grade marble from the Kongling Complex in the Yangtze Block, South China. Petrographic observations indicate that these three types of rocks experienced high-pressure metamorphism. Their mineral assemblages and P-T conditions define a clockwise P-T path involving isothermal decompression following the peak high-pressure metamorphism, which is considered to record a continent-continent collisional event. This is systematic documentation of the tectonic evolution of the Kongling Complex from 2.1-2.0 Ga deposition (constrained by youngest detrital zircon and metamorphic zircon) through ~ 2.0 Ga collision (high-pressure metamorphism) and syn-collisional partial melting (S-type granite and migmatization of TTG gneiss) to ~ 1.85 Ga post-collisional extension (A-type high-K granite and mafic dyke). These ages are broadly coincident with global collisional events (2.1-1.8 Ga) that led to the assembly of the Palaeo-Mesoproterozoic Columbia (or Nuna) supercontinent. Therefore, this study provides strong evidence that the Yangtze Block in South China was a component of the Columbia supercontinent.