Welcome to visit Geoscience!

Geoscience ›› 2021, Vol. 35 ›› Issue (05): 1240-1250.DOI: 10.19657/j.geoscience.1000-8527.2020.065

Previous Articles     Next Articles

Characteristics of Double-cross Structure in Neo-Cathaysian Structural System in the Middle-Lower Yangtze River Valley Region

LÜ Guxian1(), ZHANG Baolin2, LÜ Chengxun3, HU Baoqun4, ZENG Yong5, GUO Tao1, SHEN Yuke1, WANG Hongcai1, MA Licheng1, JIAO Jiangang6, BI Minfeng7   

  1. 1. Institute of Geomechanics, Chinese Academy of Geological Sciences,Beijing 100081, China
    2. Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences,Beijing 100029, China
    3. Geological Survey Center, China Geological Survey, Beijing 100037, China
    4. School of Earth Sciences, East China University of Technology, Nanchang,Jiangxi 330013, China
    5. Nanjing Center, China Geological Survey, Nanjing, Jiangsu 210016, China
    6. School of Earth Sciences and Resources, Chang’an University, Xi’an,Shaanxi 710054, China
    7. Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
  • Received:2020-03-20 Revised:2020-07-24 Online:2021-10-10 Published:2021-11-04

Abstract:

The tectonic system is composed of strongly-deformed structural belts and weakly-deformed region. These structural belts and blocks can be expressed in the form of structural planes. Structural plane analysis of the structural system is suitable for the study on the deformation rules, and it facilitates the tracing of structural stress field and evolution. Based on the study of the geological structures and the ore-forming/-controlling elements in the Middle-Lower Yangtze River Valley region, we summarized the distribution features of double-cross planes of the Neo-Cathaysian structural system. The double-cross structures of the Neo-Cathaysian structural system is composed of NNE-trending (25°) compressional fracture and fold belt, NNW-trending (345°, Dayishan-type) tension-torsional fractures, NEE-trending (75°, Taishan-type) compression-torsional structures, and NWW-trending (300°, Yangtze River-type) transverse extension structures. It contains three evolution stages: (1) the NNW 345° to NEE 75°-trending conjugate shear stage, (2) the NNE 25°-trending extrusion stage, and (3) the WWN 300°-trending tensile shear stage. Identification of the double-cross structural style of the Neo-Cathaysian structural system provides an important geological structural basis for the stress-strain genesis study, for the structural system formation and evolution, and for correlating shallow and deep structures. In addition, the structural planes have double-cross distribution features in other types of structural systems.

Key words: Middle-Lower Yangtze River Valley, Neo-Cathaysian structural system, double-cross structure surface, shear-compression-tension tectonic evolution

CLC Number: