The petrographic data for the studied area suggest a
recycled orogen source terrain as inferred from standard
ternary diagrams. They suggest that the dominant control on
sediment petrography within the basin was the source area
(the Taurus–Zagros ophiolitic-radiolarite belt as well as theuplifted Cretaceous and Paleocene strata of northern and
northeastern Iraq). Paleocurrent data (Al-Banna, 1982) support
that the source area for the Injana clastics appears to be in the
north and northeast. A complex interplay of other controls,
however, may also have been superimposed upon the petrography,
including source area relief and tectonics, climate,
depositional environments and processes, sedimentation rates
and changes in source area. These factors might have enhanced
the abundance of quartz and other components of the
sandstones (Mack, 1978). For example, the abundance of fresh
grains of unstable components of feldspar, igneous and
metamorphic rock fragments and unstable heavy minerals
indicate intensive tectonism in the source area with rapid
erosion and rapid transportation; it also indicates a nearby
source area, which follows from the predominance of angular
grains over rounded ones. Most of the sandstones are lithic
arenites. These types of sandstones show that the rate of
erosion must have greatly overbalanced the rate of chemical
decomposition (Folk, 1974). They also require rapid deposition
in order to preserve unstable fragments from abrasion. It
requires more rapid detrital influx due to active tectonism and
high relief. The existence of such conditions is also supported
by the fact that most of the studied sandstones are carbonaterich
sandstones.