American's sci-fi novel under construction: centre of Earth is missing! (4)
I believe the answer is:
dune
'american's sci-fi novel' is the definition.
(Frank Herbert novel)
I can't explain the remainder of the clue.
(Other definitions for dune that I've seen before include "Film" , "Seashore sand hill" , "Mound of drifted sand" , "Sandhill" , "Sandy hill" .)