Definitions for "Boulder Clay"
Keywords:  till, glacier, pebbles, glacial, clay
clay usually containing boulders or pebbles deposited by melting of ice; generally known as 'till'.
Glacial deposit consisting of boulders (grains varying in size) in a clay-dominated matrix. Boulder clay is laid down beneath a glacier or ice sheet and is typically unsorted, i.e. the grains/boulders are not in an arrangement of large at the base and small at the top of the sequence.
unstratified soil deposited by a glacier; consists of sand and clay and gravel and boulders mixed together
Keywords:  finely, rocks, ground
finely ground rocks.