Abstract: The tectonic-sedimentary setting of Puguang gas field in Sichuan basin was differently named by researchers when it was discovered. This paper suggests a terminology of aulacogen for the setting from point of view of plate tectonics and Emei taphrogeny, by which existence of Mianzhu-Zhongjiang aulacogen in western Sichuan basin is predicted and confirmed with the discovery of Pengxi-Wusheng concave platform in central Sichuan. It is concluded that the west Hubei, Guangwang-Kaijiang-Liangping and Mianzhu-Pengxi-Wusheng aulacogen groups developed in the western margin of Yangtze platform are resulted from the integrated process of three geological tectonic elements, and the dominant contributor is the dynamics of Emei mantle plume. These aulacogen groups possess potentials of natural gas prospecting.

Key words: Emei mantle plume, Emei taphrogeny, basalt, Aulacogen, natural gas, exploration potential