Abstract:
The examination of major ion geochemistry is based on the field sampling of the dissolved loads from the Changjiang River on eastern Qinghai-Xizang Plateau in the years of 2000 and 2002. The analysis of the data has disclosed that the TZ
+ values for the Changjiang River are higher than the mean values (1250
μ Eq)for all the rivers in the world, ranging mostly between 2000 and 3000
μ Eq and subordinately between 1000 and 2000
μ Eq. By and large, the abovementioned TZ
+ values may be compared with those for other orogenic belts in the world. The river water is characterized by enriched HCO
3-HCO
3- > Si +Cl
-+SO
42-, Ca
2+ > Mg
2+ +Na
++ K
+, implying that the river water is rich in Ca
2+. The enrichment of HCO
3- and Ca
2+ in the river indicates that the carbonate rocks (especially limestone)should be interpreted as the weathered source rocks in the Changjiang drainage areas.