What is another word for the planet's crust?

Search: crossword helper

Why: In the In Touch Weekly crossword, #7 down: Planet's crust

MASS_F

Answer: MASSIF! Noun: a block of the earth's crust bounded by faults and shifted to form peaks of a mountain range.

Source: OneAcross.com

The More You Know: The Face on Mars is an extra-terrestrial massif.