The Analysis Of Faults And Structural Evolution In Tuha Basin Daheyan Region

Tuha daheyan study area is located in NE-SW trending Kala Wu Chengshan,Tuokexun depression and Nearly east-west trending Bogda Mountain. Because oftectonic movement makes the fracture system and the tectonic evolution of the regionare extremely complex. This thesis based on regional geological data, seismic dat,drilling data and outcrop data，guided by petroleum geology, structural geology, oiltectonic parsing and sequence stratigraphy science theory. The key research is the twoaspects of the fault system in the region and the tectonic evolution of the Tuhadaheyan current tectonic pattern and the formation process of the tectonic units.The study based on the full use of the basic information, Implemented theoccurrence of structural elements daheyan Region fracture, preparated of the drawPermian, Triassic, Jurassic and Paleogene fault plane distribution of Figure.Combined with the calculation of the activity, we cleared the main fracture theformation time of active times, and found out what the major faults since PermianSince daheyan evolution. Combinated of balanced cross-section drawing andextrusion event analysis (shortening and shortening rate), we carried out a regionaltectonic evolution of daheyan.The results showed that:（1）The evolution of the daheyan study area hasexperienced four major periods: Late late Hercynian, Indosinian and early Yanshanianlate Himalayan period. Final late Hercynian mainly reflects the characteristics of“South weak North strong”, and the stratigraphic uplift intense reworked of the studyarea. The Indosinian inheritanced the characteristics of “South weak North strong”.The early Yanshanian mainly showing the characteristics of “West strong east weak”，tectonic uplift continues, and the region as a whole is missing Cretaceous. LateHimalayan movement is the most important extrusion folding of daheyan study area.（2）Faults of Daheyan Area are very complex. These faults were influenced mainlyby the compressive stress of north-south stress orogenic belt. They inherited many of the activities of thrust faults. Faults which control the formation of sedimentary andtectonic evolution. Current tectonic pattern of the study area in the late Hercynianprototype Indosinian development, and after Yanshanian and Himalayan partialrenovation finalized.（3）Fitting compaction factor-the depth of the relationship, getBranch teeth by depression, Karatu protrusions and depressions Tuokexun compactioncoefficient curve and equation. According to various tectonic units compactioncoefficient curve comparison can be seen: compaction factor increases with depth;same depth compaction factor than the new strata big old strata; Sag compactionfactor than the bump compaction factor large.（4）The planar distribution point ofview from the main shortening rate the characteristics of each period: Profileshortening rate characteristics in the Himalayan period daheyan study area is “northstrong south weak”and“west strong east weak”. In the Yanshan period thecharacteristics is “south strong north weak”and “east strong west weak”. Intenseperiod of tectonic activity, formation shortening is also more severe.