Study of Pyroxene in Junggar Basin Basement Volcanic Rock and Its Indicator to Basin Basement Characteristics

Junggar basin basement can be divided into three areas (west, north and south) by data from drilling and aeromagnetism. These areas contain all sorts of chemical components and type names of pyroxene. While these pyroxene chemical components are shown to be quite different by the volcanic rock alkalinity, its evolution trend, formation tectonic environments and its tectonic environment evolution history. This proves that Junggar basin basement is composed of amalgamation of the growing continent of the southeastern margin of the Kazakhstan plate, the southwestern margin of the Siberia plate and the northern margin of the Tarim plate. During the amalgamation, the western and northern parts joined together earlierly, and formed the continent by the uplift in the early Hercynian orogeny in the late Early Carboniferous. While the southern part was relatively late in the continent formation and Late Carboniferous plate movement caused the combination of the southern and the northwestern continents thus forming the complete Junggar basin fold basement.