三塘湖盆地北西向构造变形带的正演

The Forward of Westnorthern Structural Deformation Belt in Santanghu Basin

三塘湖盆地北西向构造变形带的形成与演化控制了盆地总的构造格局．平衡剖面的正演表明：控制盆地构造变形的滑脱面位于石炭系内部的泥岩层中，滑脱面的深度约４．４６ｋｍ；盆地北西向构造变形带是海西晚期和喜山期两期构造作用叠加的产物，变形带的扩展顺序呈前展式自南向北扩展；变形机制主要为受重力扩展作用控制的断弯褶皱作用；变形样式主要为断裂及相关褶皱．盆地总的缩短量最大约８．３ｋｍ，海西晚期最大缩短量约４．５ｋｍ，喜山期最大缩短量约５ｋｍ．

The formation and the evolution of westnorthern structural deformation belt in Santanghu Basin determine the general structural framework of the basin.The forward of the equilibrium section of the basin shows that,the detachment surface controlling the structural deformation of the belt is in carboniferous mudstone statum,and the depth of the detachment surface is about 4.46km;the belt is the result of structure evolution in the periods of late Hercynian and Himalayan Orogeny,and it extended from the south to the north in the basin;its deformation mechanism is fault bend folding caused by gravity propagation,its deformation styles are faults and folds related to the faults.The total shortening value of the basin is about 8.3km,with the maxium shortening values during late Hercynian period and Himalayan Orogeny period being about 4.5km and 5.0km respectively.