Figure 3. Distribution of some soil characteristics in the soil surface horizons across western Canada: (A) clay content in the surface soil horizons, % of texture; (B) mineralogical composition of surface soil horizons: Mte, montmorillonite; Kte, kaolinite; Qtz, quartz; Ch, chlorite; ORG, organic horizon without mineral fraction. First is dominant mineral followed by remaining occurred minerals; (C) soil organic matter content in the surface soil horizons, %; (D) humus content in the surface soil horizons, %; (E) soil pH.