Characteristics of the Capping Superposed Fold in the Northeastern Margin of Jiangnan Orogen, China [江南古陆东北缘盖层叠加褶皱特征]

作者：Chen X.-Q.^*

来源：Journal of Earth Sciences and Environment, 2019, 41(1): 15-28.

• interference pattern
• Jiangnan orogen
• regional scale
• stereographic projection
• stress field
• superposed fold
• tectonic geology
• tectonic sequence

The tectonic attribute of the capping fold developed in Paleozoic-Early Mesozoic in the northeastern margin of Jiangnan orogen is gradually recognized, but there is not research report about the superposed folds and their superposed patterns in the study area at present. Based on the field investigates, Caledonian and Indosinian fold structures develop in the northeastern margin of Jiangnan orogen. Based on the characteristics of the superposed folds and the restoration of stress field, the geometry and kinematics characteristics of superposed folds are discussed by structure analysis and stereographic projection method, and there are three stages of the capping superposed fold deformation, including the first fold (F1), the second fold (F2) and the third fold (F3). In the early stage, the cap suffers SN compression, and forms Late Caledonian EW-nearly fold (F1); then, the first fold suffers SE-NW compression, and forms Early Indosinian NE or NNE fold (F2); in the later stage, the second fold suffers NE-SW compression, and forms Late Indosinian-Early Yanshanian SN-nearly or NNW fold (F3). The regional superposed folds mainly have vertical span and slant span styles, and develop various Interference patterns. The results show that the second fold diagonally overprints the first fold, and forms the basic structural pattern in the area. The study on the structural characteristics and deformation evolution of superposed folds has great significance on the reconstruction of tectonic framework and geological prospecting.

• 单位
  合肥工业大学