Wietrz=F(t,woda)

Fig. 3.11 The solubility of aluminium and Silicon as a function of pH. In the shaded area aluminium is morę solublc than Silicon and may be preferentially removed from s weathering profile.

illite

Mica

Mi ye^¹ icy^r clays

raldspars Fo-Mg srhates

** Smectites-— * K^oiinite

♦ Gibbsite

Si/AI    2/1    1/1    0/1

Time_    »

Leaching Intensity_*

Fig. 3.18 The production of clay ninerals by weathering as a function of leachir.; int*ns!.y.