Assertion: soil's horizon | /r/CapableOf | form at the surface
Facets:
value: below an o horizon
type: LOCATION
Source sentences:
text: A horizons are mineral layers that formed at the surface or below an O horizon, that exhibit obliteration of all or much of the original rock structure, and that show one or both of the following: an accumulation of humified organic matter intimately mixed with the mineral fraction and not dominated by properties characteristic of E or B horizons