Analysis Of The Tectonic And Evolution Characteristics Of The Kolameishan Piedmont In The Junggar Basin

This paper selected the piedmont of the Kelameili Mountains in the northeast of Junggar Basin as the research object,based on seismic data,with structural modeling theory,from the perspective of structural analysis, the integrated use of structural geology, seismic geology and so on, and used the tectonic interpretation of seismic sections in the study area and the surface geological investigation, gravity and magnetic data,combining previous research results, analysis of the stratigraphic contact relations, regional stress characteristics, tectonic deformation and evolution mechanism, and the analogy in different tectonic deformation mechanism under the deformation difference,to systematically study the Kelameili Mountains Piedmont in the late Paleozoic-Cenozoic tectonic evolution, reveals the torsional stress under the tectonic characteristics and the evolution process of the dynamic structural belt in the study area, further clarifies the relationship between structure and oil or gas.Based on the new and old 2-D seismic sections in the piedmont of the Kelameili Mountains, and that choosed typical seismic sections did balanced section restoration, the tectonic evolution in the study area was discussed in this paper. And obtained the following main results:1.The piedmont of the Kelameili Mountains in the northeast Junggar Basin is controlled by regional right spinning torsion stress,and with the positive tectonic zone in the Junggar Basin,it formed the broom structural system.And it has a complex contact relationship,mainly includes the fracture contact and unconformable contact.2.Carboniferous is the main objective of the study area layer system, among them,the Bashan group's volcano rocks are widely distributed in the coverage area of the basin and surface outcrop area.On the basis of lithological association of the volcano rock, Bashan group is divided into two sequence lithology,and there are sedimentary rocks which represent the intermittent of volcanism between them.3.Based on this research, the piedmont of the Kelameili Mountains's tectonic style is thrust-nappe structures.The boundary between the eastern part and the western part is the Zhangpenggou uplift, each section of the internal tectonic styles are from the west to the east by the low angle distance thrust to high angle thrust type, but there are differences between faults and tectonic trend in the two sections, the western part is the north west trending, the eastern part is nearly run west to east trending.4.The balanced section technique is used to recover the inversion of seismic section in the study area, combining regional evolution characteristic and previous research results, preliminarily suggests that structural belt in the study area can be summarized into four main stages:middle Hercynian period,late Hercynian period, Indosinian period-early-middle Yanshan period and late Yanshan period-early Himalayan period.5.Volcanic rocks of carboniferous has the advantageous condition to preservation under the low angle distance thrust nappe, this is the mian direction of oil and gas exploration in the next step.