Rivers extended their channels across these newly emergent continental shelves and cut rapidly downward through the soft sediments to form valleys that exist today as submarine canyons.
(Rivers; extended; their channels; across these newly emergent continental shelves) (Rivers; cut rapidly downward; through the soft sediments; to form valleys) (valleys; exist; T:today; as submarine canyons)
Rivers Rivers valleys
extended cut rapidly downward exist
their channels across these newly emergent continental shelves
through the soft sediments to form valleys
T:today as submarine canyons