The debris may have been taken off the valley floor as a glacier moved or fallen off the valley walls as a result of weathering.
(The debris; may have been taken; off the valley floor; T:as a glacier moved or fallen off the valley walls as a result of weathering) (a glacier; moved; ) (a glacier; fallen; off the valley walls; as a result of weathering)
The debris a glacier a glacier
may have been taken moved fallen
off the valley floor T:as a glacier moved or fallen off the valley walls as a result of weathering
off the valley walls as a result of weathering