Extension by igneous dikes at depth, normal faults in the upper crust. 2 图12-8伸展区地壳结构剖面 马杏坦,1982,据G.P. Eaton,1980,修改) 1.断块状地表岩层;2.韧性中间层 3下地壳层;4岩石圈地幔Extension by igneous dikes at depth, normal faults in the upper crust