Mazatage Arcuate Structure in Map-view and Oblique Thrust in Tarim Basin, Western China(PDF)
《地球科学与环境学报》[ISSN:1672-6561/CN:61-1423/P]
- Issue:
- 2018年第04期
- Page:
- 381-397
- Research Field:
- 基础地质与矿产地质
- Publishing date:
Info
- Title:
- Mazatage Arcuate Structure in Map-view and Oblique Thrust in Tarim Basin, Western China
- Author(s):
- YANG Geng
- Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
- Keywords:
- arcuate structure; detachment fold; oblique thrust; shear fault bend folding; strikeslip fault; partially restoration; Mazatage; Bachu uplift
- PACS:
- P542
- DOI:
- -
- Abstract:
- The collision between India Plate and Asia Plate has a strong impact on the deformation of the orogenic belts and basins in the western China, especially much of the deformation is centered on the internal Tarim Basin with the rigid basement, which is mainly in and both sides of Bachu uplift. The north toward Mazatage arcuate structure in map-view, which is located in the southern deformation sides of Bachu uplift, is covered by Quaternary sedimentary terrestrial clastic rocks. The poor reflection of the seismic data in the both limbs nearby the core of Mazatage anticline has given many structural interpretations of Mazatage structural belt, because the wells, mainly located in the cores of Mazatage anticline, are relatively shallower and unrevealed deeper strata. The Mazatage actuate structural belt can be divided into three parts in map, including the northeastward west part, the east-westward middle part and the northwestward east part, which were respectively separated by Ma7-well lateral ramp and a transversal Ma4-well strike-slip fault. By wells and 2D seismic data, the reinterpreted seismic data show Mazatage anticline is a typical mid-Cambrian-gypsum-cored detachment folds both in the western part and central part of Mazatage arcuate structure with thrusting northward, in which two thrust faults are developed in both the core and in south limb of the anticline. According to the structural styles in detail, it is found that a mid-Cambrian-gypsum-cored Mazatage detachment anticline restored by removing thrust faults shows a shortening of Cambrian-Ordovician is greater than that of Carboniferous-Permian, and can be interpreted a simple shear fault-bend fold resulted by both Mazatage thrust and Gudongshan thrust fault with strike-slip shear faulting in the north limb of anticline in the west part of Mazatage arcuate structure. In the eastern part of Mazatage arcuate structures, an anticline is developed by North Mazatage thrust fault with strike-slip shear faulting in the south limb of anticline, and can be interpreted a simple shear fault-bend fold. The section restored by removing thrust faults illustrates that the shortening from Early-Middle Cambrian to Late Ordovician increases greatly, but decreases gradually from Carbonic to Late Permian. The detached Mazatage anticline restored by removing thrust faults shows that the shorting of Paleozoic strata from Permian to Cambrian is not changed in the central part without shearing in the north limb of anticline. The interpretation of seismic data shows that there is a sinistral component of transcurrent movement added to the north thrusting in the western part of Mazatage arcuate structures, and a dextral component of transcurrent movement added to the north thrusting in the eastern part.
Last Update: 2018-07-27