The first phase involves the formation of thrusting and napping towards nww accompanied by extensive igneous activity and mineralization . the second phase corresponds to the development of asymmetrical small fold downwards north and south . the final phase the cenozoic is marked by strong brittle fractures activity resulting in the sharp heave of the landform of xiaoqinling aera 太华群内的褶皱及南北两侧断裂分析表明，小秦岭燕山期至少经历3期变形，第一期为sse nww向的褶皱变形作用；第2期为南北向正断下滑剪切作用；第3期为脆性正断作用。
