In fact, the powerful abrasive wear of the water flowing across the rock over time has caused the weaker basaltic rock to erode away.
(the water; flowing; across the rock; T:over time) (the powerful abrasive wear of the water; has caused; the weaker basaltic rock to erode away) Context(the powerful abrasive wear of the water has caused,List([9, 93))):(the weaker basaltic rock; to erode; away)
the powerful abrasive wear of the water has caused,List([9, 93))
the water the powerful abrasive wear of the water the weaker basaltic rock
flowing has caused to erode
across the rock T:over time
the weaker basaltic rock to erode away
away