It consists of sand-dune deposits, formed when the region was a Sahara-like desert.
(It; consists; ) (sand-dune deposits; formed; T:when the region was a Sahara-like desert) (the region; was; a Sahara-like desert)
It sand-dune deposits the region
consists formed was
T:when the region was a Sahara-like desert
a Sahara-like desert