Assertion: r horizon | /r/DistinctFrom | boulder
Facets:
value: of hard rock
type: OTHER
Source sentences:
text: Unlike the above layers, R horizons largely comprise continuous masses (as opposed to boulders) of hard rock that cannot be excavated by hand.
text: Unlike the above layers, R horizons largely comprise continuous masses (as opposed to boulders) of hard rock that cannot be excavated by hand.