Outcrop it showed as line on the globe (6)
I believe the answer is:
tropic
'line on the globe' is the definition.
'tropic' can be an answer for 'line' (tropic is a kind of line). I am not sure about the 'on the globe' bit.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for tropic that I've seen before include "One of two parallels of latitude" , "Duck" , "Latitude twenty-three degs twenty-six mins north or south" , "Latitude 23 and a quarter 26 N or S" , "Cancer/Capricorn line" .)