Variations of thick-skinned deformation along tumuxiuke thrust in Bachu uplift of Tarim Basin, northwestern China

• Published in: Journal of structural geology Vol. 144; p. 104277
• Main Authors: Song, Zhihua, Tang, Liangjie, Liu, Chao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2021
• Subjects: Positive inversion; Push-up structure; Short-cut thrust; Thick-skinned structure; Transpressive deformation; Trishear fault propagation fold; Transpressive deformation; Short-cut thrust; Thick-skinned structure; Trishear fault propagation fold; Push-up structure; Positive inversion
• ISSN: 0191-8141; 1873-1201
• DOI: 10.1016/j.jsg.2021.104277

The curved Tumuxiuke thrust is the northeastern boundary of the Bachu uplift in the Tarim Basin. Based on the interpretation of 2D seismic reflection sections, thick-skinned deformation along the Tumuxiuke structural belt is characterized by monoclinal fault-propagation folds that alternate with push-up structures. The localization and patterns of thick-skinned deformation were controlled by pre-existing normal faults. The forward trishear modeling process further revealed the existence of short-cut thrusts branched from pre-existing normal faults and tested their effect on folding deformation. Monoclines decapitated by low-angle short-cut thrusts coexist with anticlines decapitated by high-angle inverted faults due to the selective inversion of pre-existing normal fault segments. Furthermore, the fault propagation to fault slip ratio (P/S) and the combined effect of multiple propagating thrusts determine the variations in the fold amplification rate and the growth-stratal architecture. The coeval activity of the western Kunlun orogen and the Tumuxiuke thrust in the Cenozoic indicates the far-field transmission of orogenic stress into the distal foreland. Under the approximately N–S-directed compressive stress, inverted structures in nearly W-E-striking segments exhibit monoclinal fault-propagation folds controlled by forethrusts; for the oblique NW-SE-striking segments, the transpressional deformation was partitioned into the frontal contractional deformation zone and the backlimb strike-slip zone.