Abstract:
There are two decollement strata in southwestern depression of Tarim Basin:one is 500 m Middle Cambrian saltgypsum layer,and another is 100~700 m Lower Paleogene gypsum mudstone with limestone and dolostone.The Middle Cambrian saltgypsum layer is mainly related with Mesozoic and Late Miocene structural deformation,however,the Lower Paleogene gypsum mudstone is mainly involved in Late Pliocne and Quaternary structural deformation.The decollement structure is the most important structural style.The decollement structure and other structural styles consist of four kinds of structural assemblages in section: 1)decollement fault related fold; 2)imbricated decollement structure; 3)wedging structure+reconstructed faultrelated fold; 4)detachment fault+fault related fold.The former two structural assemblages mainly distribute in Maigaiti slope and its periphery,and the latter two structural combinations mainly distribute in fold and thrust belt of western Kunlun Mountain.The structural modes of these structural styles are set up,which are significant to structural interpretation and identification of traps of complicated areas in southwest Tarim Basin.