安宁河裂谷的“活化”

安宁河裂谷位于"攀西裂谷"的中轴部位,近期研究发现,裂谷区有显著的地壳引张作用,存在地幔隆起与热对流。通过野外实地调查,结合地球物理、断裂、沉积、地震、地应力和地形变等资料,认为安宁河裂谷区现在正处于明显的构造活化状态。这种活化受上地壳塑性流动产生的水平挤压和地幔隆起产生的应力张量的共同作用。据此提出一个新的裂谷活化地壳力源模型,认为在研究区特定的地球动力环境下,以安宁河裂谷为中心,再现岩浆活动和地壳裂陷并非不可能。

The activation of Anninghe rift valley

Anninghe rift valley is located at the medial axis of Panzhihua-Xichang rift valley. Recent research shows that there is an obvious crustal tensional process in the valley region, and a mantle uplift and thermal convection system exists beneath the crustal. Through field investigation, combining with analyzing research data on geophysics, faults, sedimentary, earthquakes, ground stress and geodetic deformation, we consider that Anninghe rift valley is in a significant tectonic activation process which is controlled both by the horizontal pressure from plastic-flow of the upper crustal and the tensional stress from the mantle uplift, hereby, a new crustal force source model is put forward. Considering the specific geodynamic environment, we believe that in study area there is a possibility magmatic activity and crustal sinking would reappear.