English to Arabic Science Geology rock formations.

Last one in the same paragraph:
The iron-ore deposits of Liberia are Archaean-age iron formations of itabirite type and are associated with metavolcano-sedimentary formations overlying and tightly infolded into the predominantly gneissic basement complex.

Basement complex: The suite of mostly crystalline igneous and/or metamorphic rocks that generally underlies the sedimentary rock sequence.
source: http://www.isgs.uiuc.edu/glossary.htm

I have run out of ideas for this one.