DETERMINATION OF THE MESOZOIC VOLCANIC EDIFICE AT TAOYUANZHAI IN THE INTERIOR OF THE DABIE MOUNTAINS AND ITS GEOLOGICAL IMPLICATIONS

Based on largescale geological mapping of volcanic rocks and detailed petrological and geochemical studies of the volcanic rocks at Taoyuanzhai, Yuexi county, Anhui province, the authors have determained that there exist relict Mesozoic volcanic rocks and volcanic edifice in the gneiss basement in the interior of the Dabie Mountains. It shows that the Dabie Mountain block had neither risen by a large amplitude before the Mesozoic nor was the rootmountain of the Mesozoic orogenic belt. The main factor for the dramatic uplift of the Dabie Mountain block was the largescale magmatism in the Yanshanian period.