Beishan structural data 2025
Description
List of σ1, σ2 and σ3 of the major folds, including the Shapoquan syncline, Xigou anticline, Nanquan syncline and Baishawo synclinorium, and the minor folds within the Hongliudaquan fold and thrust system, Beishan fold-thrust belt.
Files
Steps to reproduce
σ1: greatest principal stress direction, equal to maximum shortening direction (MSD); σ2: intermediate principal stress direction, equal to fold axis or “π” axis; σ3: least principal stress direction. The MSD is calculated by using a ‘π’ diagram. This method requires plotting the limbs of folded bedding as poles. The bedding poles to each limb are fitted to a common great circle, known as a ‘π’ circle . The pole to ‘π’ circle, known as the ‘π’ axis, refers to the trend and plunge of the fold axis. The axial plane is a close approximation to the bisecting surface of the fold, another great circle that passes through the ‘π’ axis (or fold axis). So, the pole to the axial plane is equal to the MSD (σ1) , the ‘π’ axis represents the σ2.
Institutions
- Chinese Academy of Geological Sciences