柴达木盆地沉降演化机制的研究

为拟合柴达木盆地区坳陷沉降期的沉降曲线，用分层地球模型的解析理论计算了由沉积物载荷引起的粘弹性沉降。然后用一个空间平面模拟了区域性差异沉降。基于以上计算结果，进一步推测了盆地内部断层可能引起的差异沉降。结果表明，柴达木盆地的总沉降量是粘弹性沉降、区域性差异沉降及盆内断层的差异沉降３个因素共同作用的结果。在此基础上，文内用有限元法的平面应变模型研究了盆地的沉降特征与区域构造应力场之间的关系。本文最后

A Study of the Snbsidence Mechanismof the Qaidumu Basin

In order to fit the subsidence curves of the Qaidumu Basin in the depressionPeriod, the viscoelastic subsidence of the basin caused by sediment loads is first compu-ted with an analytical tlieory of a layered earth znodel. Then, the regional differentialsubsidence is simulated by means of a spatial plane. On the basis of the above compu-tations, the possible differential subsidence of internal fanlts in the basin is furtberdeduced. The results show that the whole subsidence of the basin comes of the visco-elastic subsidence, the regional differential subsidence and internal faults' differantialsnbsidence altogether. In addition, the relationship between the subsidence characteristicsof the basin and the regional structural stress fields is studied by use of a plane strainmodel with the finite element metliod. From the results, the regional strnctural stressfields that the basin was subjected to in the evolution are deducible.