Superimposed features and deformation mechanism of Early Mesozoic folds in the Sangzhi-Shimen area, northern Hunan

• Published in: 地质科技通报 Vol. 40; no. 6; pp. 43 - 54
• Main Authors: Jun Yang, Peng Luo, Yuexin Ling, Shaohui Yang, Daoyuan Bai, Fanghui Wei, Shunhong Cao, Nengli Peng
• Format: Journal Article
• Language: Chinese
• Published: Editorial Department of Bulletin of Geological Science and Technology 01.11.2021
• Subjects: deformation mechanism; deformation period; sangzhi-shimen complex syncline; structural analysis; superposed fold
• DOI: 10.19509/j.cnki.dzkq.2021.0605
• ISSN: 2096-8523

A series of Jurassic-type folds have continuously developed in the Mesozoic from the Sangzhi-Shimen area in northern Hunan. The analysis of the fold superimposition characteristics is of great significance to explore the deformation period and deformation mechanism of the Sangzhi-Shimen complex oblique folds, and also for the theoretical study of fold deformation controlled by faults. Based on the measurement of geological structure section and analysis of fold superimposition characteristics in Sangzhi-Shimen area, two fold structures in Indosinian and early Yanshanian were identified. The low-angle unconformity contact between the Jurassic and the Middle Triassic in the study area, and the high-angle unconformity contact between the Cretaceous and the Pre-Cretaceous reflect two deformation events of Indosinian and Early Yanshanian movement. It can be further inferred that the folds in the Sangzhi-Shimen area can be divided into two phases: the Indosinian movement and the early Yanshanian movement.The Indosi