Widespread intraplate deformation within mainland Southeast Asia is conspicuously expressed by northwest trending strike-slip faults which originate near the eastern Himalayan syntaxis. These include the Ailao Shan–Red River Fault Regional tectonic elements of mainland Southeast Asia. Horizontal line ornament, Western Province granites; dotted ornament, Main Range granites; vertical line ornament, Eastern Province granites; pale grey, Cenozoic basins; black lines, brittle faults; grey half arrows, ductile shear sense; black half arrows, brittle shear sense. After Cobbing et al., 1986 and Morley, 2002, and Polachan (1988).