INTRODUCTION More than a decade has elapsed since the illuminating study of J.S.Lee and Y.T.Chao~1 on the geology of the Yangtze Gorges.The puplica-tion of C.Y.Hsieh and Y.T.Chao’s Memoir~2 dated only two years later.So the necessity of restudying this critical region in the light of the INTRODUCTION More than a decade has elapsed since the illuminating study of JSLee and YTChao ~ 1 on the geology of the Yangtze Gorges. Puplica-tion of CYHsieh and YTChao’s Memoir ~ 2 dated only two years later. restudying this critical region in the light of the