Deep divides (6)
I believe the answer is:
chasms
'deep divides' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for chasms that I've seen before include "Deep fissure in the earth" , "Deep gorges, crevasses" , "Deep openings in the earth's surface" , "Big gaps" , "Deep fissures in the earth" .)