Answer: fissures

AnswerCrossword Clue
FISSURESCrevices.
fissuresA state of incompatibility or disagreement
fissuresA long, narrow opening or line of breakage made by cracking or splitting, esp. in rock or earth
fissuresFISSURE, to split (to separate lengthwise)
fissuresA long narrow opening in the form of a crack or groove, e.g., any of the spaces separating convolutions of the brain