从实验岩石变形过程探讨四川盆地加里东古隆起的形成机制

岩石力学实验表明 ,处于脆性、半脆性 -半延性域的岩石 ,其变形经历两个阶段 ,前期的变形相对均匀分布阶段和后期的变形集中化阶段。把此认识应用于四川盆地加里东古隆起的形成研究中 ,得到 :古隆起及周围岩石圈古生代在区域拉张力的作用下 ,先经历了变形相对均匀分布阶段 (Zb- O) ,形成了乐山 -龙女寺及天井山古隆起 ;后经历了变形渐进式集中化阶段(S- P) ,先形成了乐山 -龙女寺与天井山联合古隆起 (S) ,后形成了更大范围的联合古隆起 (D- P) ;后期阶段的变形主要集中于龙门山断裂等少数断裂上。

ON FORMATION MECHANISM OF CALEDONIAN PALEOSWELL IN SICHUAN BASIN FROM EXPERIMENTAL ROCKS DEFORMATIONAL PROCESS

Experimental deformation of rocks which is brittle or semibrittle or semiductile generally undergoes the early stage during which deformation is relatively homogeneously distributed in samples and the late stage during which deformation concentrates on minority faults. The above knowledge is applied to the formation of the Caledonian paleoswell in Sichuan Basin. The result is that under the regional tensile stress, the lithosphere in range of the paleoswell early undergoes relatively homogeneously deformation stage (Z b O) during which the Leshan Longnushi and Tianjingshan paleoswell forms and late undergoes gradually concentrated deformation stage (S P) during which the combined Leshan Longnushi and Tianjingshan paleoswell (S) and the larger combined paleoswell (D P) successively form. In the second stage, deformation concentrates on minority faults, e.g. the Longmenshan fault, etc.