The slow-moving glacial ice superficially changed the landscape as it scraped over previously existing mountains and valleys, transporting rock debris for miles.
(The slow-moving glacial ice; superficially changed; the landscape; T:as it scraped over previously existing mountains and valleys, transporting rock debris for miles) (it; scraped over; previously existing mountains and valleys) Context(it scraped over,List([67, 82))):(it; scraped over previously existing mountains and valleys transporting; rock debris; for miles)
it scraped over,List([67, 82))
The slow-moving glacial ice it it
superficially changed scraped over scraped over previously existing mountains and valleys transporting
the landscape T:as it scraped over previously existing mountains and valleys, transporting rock debris for miles
previously existing mountains and valleys
rock debris for miles