Hematite and its association with goethite

On a global scale, a line which separates goethitic soils at higher latitudes from hematitic ones at lower latitudes (zonal soil association) can be drawn on both hemispheres. The exact position of this line is not yet known. In the northern hemisphere it is located in Southern China, Southern Europe and the Southern United States 

On even smaller scales, one can also find differentiation between goethite and hematite within a soil profile. Often, yellow, hematite-free toposoils are underlain by red 

The following scheme summarizes the environments of formation on different scales  

Humid rain forest without dry periods 0 1 Savannah with dry periods 

Lower parts of a toposequence 1 A Upper parts of a toposequence 

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