ABSTRACT
Weathering of silicate minerals is a slow process and the resulting changes in water chemistry will be gradual and less conspicuous than in carbonate aquifers (Chapter 5). Still, weathering of silicate minerals is estimated to contribute about 45% of the total dissolved load of the world’s rivers (Stumm and Wollast, 1990). In the global cycle of CO2, the weathering of silicate minerals acts as an important CO2 sink. Furthermore, silicate weathering is the most important pH-buffering mechanism in sediments without carbonate minerals. Because the rate of silicate dissolution is slow, aquifers in silicate rock are vulnerable towards acidification. Also, forest deterioration due to acid rain has focused attention on silicate weathering as pH-buffer.
