Application for prototype basin analysis in the Paleo-tectonic stress fields in Jurassic, western margin Ordos basin

摘要

As the tangible product of tectonic movement, tectonic deformation is the "fossil" to study of crustal stress field characteristics and evolution history. However, the strata outcrop is limited in the region, which experienced in varied geodynamic setting. It is difficult to analyse the evolutionary history and the character of regional stress fields accurately. So, different conclusions will be appeared. To reconstruct the tectonic stress is the key to restore the prototype basin and to evaluate regional resources. Combining the analysis of syndepositional tectonic features in basin with regional tectonic environment, ways and directions of the tectonic stress in late Jurassic were determined in western margin, Ordos Basin. Then the tectonic stress field and strain field were simulated by the finite element software ANSYS system. The results show that it was nearly EW-trending compressive stress in late Jurassic, western margin, Ordos Basin, which was controlled by Alashan block eastward extrusion in compressive stress.