Sandstone geochemistry
The majority of the sandstones (Table 2) have a SiO2
content ranging between 27 and 43 wt.% (average 34%) for
the Fat’ha Formation and ranging between 35 and 50 wt.%
(average 41%) for the Injana sandstones and with K2O/Na2O
ratios generally between 1.5 and 5.5 for the Fat’ha sandstones
and between 0.5 and 1.5 for the Injana sandstones. Values of
Fe2O3
+ (total Fe as Fe2O3) + MgO contents are between 7 and
15 wt.% for the Fat’ha Formation and between 2 and 10 wt.%
for the Injana Formation and can be classified as low to
moderate. Large-ion-lithophile (LIL) elements, such as Rb, Sr
and K, show a range of abundance. Similarly, the transition
elements (Ni, Cr, and V) show variable inter-element ratios.