Podzolic Soils - Major Soil Groups of the World - page 340

5. Since silica is presumed to migrate in the free state while iron
will be complexed, no close correlation should be found between
the contents of Si and Al. But one is always found and that too,
very strong (Si/Al = 0.5 as in imogolite)!
6. The boundary between E and Bh is always abrupt, which does
not agree well with a process of depletion by transport and then
precipitation; contrarily, the Bh/Bs boundary is always gradual;
how can we explain this?
7. As the E horizon is presumed to give its material to the B, the
deepening of the former must be correlated with the thickening
of the latter. On the contrary, below the thick white sands of
tropical soils differentiated at the expense of lateritic soils, we
find B horizons reduced to a thin border (Fig. 11.13b).
8. If the substances imported from the top of the profile had
accumulated at the top of the B, they would have risen vertically
with time. The E horizon, while becoming more distinct, should
have its thickness reduced! But, on the contrary, from the few
centimetres it is in recent Podzols, it becomes several decimetres
or even several metres in old Podzols. The E/B boundary
descends with time, which implies progressive dissolution of
the top of the B horizons, totally contradicting what is postulated
in the classic model, which is inconsistent on this point.
Fig. 11.9 Vertical section showing the Bh horizon in rings around nuclei of Bs in a Podzol of
Guyane on a sand dune. The boundaries were highlighted on the original colour photograph.
The E horizon penetrates downward (black arrow). The mattock, top right, gives the scale.
Photo : Robert Bouzigues.