Gigaimages / virtual microscope


Contact between Bt and BCkt horizon in a Calcic Palexeral decapitate.

When the soil decapitates, the bottom of both horizon Bt and Ck adjust and the illuviation clay horizon invades the carbonate accumulation horizon.

Thin section RNS16-4. Limit Horizon between 2Bt3 and 2BCtk.


Low/medium magnifications
Low/medium magnifications


Micromorphological features

After browsing these images you should have found, at least, the following characteristics (left side image only with poloarizer, the one on the right side with crossed nicols).

Bt horizon. Almost all the clay has illuvial origin
Ckt horizon. Illuvial clay coating  in a micritic carbonate plasma (calcite)
Two fase illuviation clay. First, the yellow one, later the orage one, thus representing a change in the soil climate conditions.
Composed coating over a pore. First, carbonates, second illuvial clay, third carbonates, four clay and finally carbonates again ( 5 changes in the soil conditions; and another additional showed in the yellow illuvial coating clay and the orange one on the upper area of the microscope field).
Replacement of muscovite by the carbonates

Ai, illuvial clay; C, micritic carbonates
p, voids; Q, sand quartz; M, muscovite; B, biotite; Mr, muscovite replaced by carbonates

Soil data

The profile

The landscape

General features

Morphology, physical and chemical analysis

Micromorphological images: Hor Ap       Hor Bt1     Hor 2Bt2      Hor 2Bt3     Hor 2BCtk     Hor 2CBtk     comparative study



This soil was presented in XIII Reunión Nacional de Suelos in Salamanca in 1985.