55 terraces along 32 rivers in eastern Guangdong and

14

C and TL ages from 25 samples are studied in this paper. There are at most 6 stages of river terraces in the region

of which the highest one is 70 m in height

and is distributed near present-day main riverbed. The first stage terraces include normality terraces (in the upper part of Lijui Town in Longchuan)

semiburied terraces (from Lijui to Yuanzhou Town in Boluo)

and buried terraces (from the downstream of Yuanzhou to the Dongjiang River Delta)

with decreasing ages. This indicates that the tectonic lift occurred earlier or the lift rate was faster in the areas of river head and the tectonic activity was gradually stabilized or sunk in the areas of mid-downstream. There are at least 12 sites where typical denudeplanation surface gravel layers were found. They show the following characteristics: (1) They are distributed on the highest terraces with elevation of 20～200 m

coincident with local denudation platform. (2) They are located on terraces of the highest rank with large area in the region. (3) The denudeplanation surface gravel layers in Yulu of Shiyan Town

Pingling Town

Dongkeng Town

Shuichun Town

and Zhangfang Town are formed from former rivers. The valleys-in-valleys became today's little rivers with narrow riverbed and flood land

maybe with the first terraces

during the past hundreds of thousands years. (4) The denude-planation surfaces have two slope directions

towards the valley and the downstream in the basin

but generally towards the South China Sea.