Cutans are the modification of the soil texture, or soil structure, at natural surfaces (particle, pore, or ped) in soil materials due to illuviation. Cutans are oriented deposits which can be composed of any of the component substances of the soil material. Cutans are common features in soil and represent focuses of chemical and biological reactions. Cutans may include clay skins or coatings of silica, sesquioxide, manganese, ferromanganese, soil organic matter or carbonate. Clay skins are also called argillans, and soil horizons with sufficient clay illuviation are termed argillic horizons.
Cutans provide physical evidence, observable in the field, as to the degree and nature of pedogenesis. The ability to assess cutans is a core skill in soil morphology and paleopedology.
O little town of Bethlehem,
How still we see thee lie
Above thy deep and dreamless sleep
The silent stars go by
Yet in thy dark streets shineth
The everlasting light
The hopes and fears of all the years
Are met in thee tonight
For Christ is born of Mary
And gathered all above
While mortals sleep the angels keep
Their watch of wondering love
Oh morning stars together,
Proclaim the holy birth
And praises sing to God the king
And peace to men on earth
How silently, how silently
The wondrous gift is given
So God imparts to human hearts
The blessings of his heaven
Oh morning stars together
Proclaim the holy birth
And praises sing to God the king
And peace to men on earth
The hopes and fears of all the years