Translation of "maakerros" into English

layer of sedimentary rock having approximately the same composition throughout

Distinctive successive layers of soil produced by internal redistribution processes. Conventionally the layers have been divided into A, B and C horizons. The A horizon is the upper layer, containing humus and is leached and/or eluviated of many minerals. The B horizon forms a zone of deposition and is enriched with clay minerals and iron/aluminium oxides from the A layer. The C layer is the parent material for the present soil and may be partially weathered rock, transported glacial or alluvial material or an earlier soil.(Source: ALL)