The Middle Miocene Fat’ha sandstones have a mean
quartzo-lithic composition of Q58F16L26, while the Late
Miocene Injana sandstones have a mean value of Q14F24L62.
According to their composition, the sandstones of the Fat’ha
and Injana formations from northern Iraq are lithic arenites,
rich in carbonate lithic fragments. Al-Rawi (1979, 1982)
defined the carbonate-rich sandstones as lithic and sublithic
arenites and wackes which contain more terrigenous carbonate
rock fragments and carbonate cement than other rock fragments.
In general, they consist of angular to subrounded grains
of quartz, feldspar and rock fragments consisting principally
of carbonate and chert with variable amounts of metamorphic
and igneous rock fragments and smaller amounts of sandstone
and argillaceous rock fragments.