The Hangu Formation (Paleocene) consists of sandstone, siltstone, carbonaceous shale, coal and laterite. It is well exposed in the Trans Indus Surghar range and the southern Hazara basin. The sandstone is yellowish brown, fine to coarse grained and medium to thick bedded. The sandstone of the Hangu Formation is classified as quartz arenite on the Q-F-L diagram. It is mostly grain supported and are cemented by silica cement. The study of different stratigraphic sections reveal that Hangu Formation can be sub-divided into a number of lithofacies on the basis of sedimentary structures and lithological variations. These include lateritic lithofacies, coal and carbonaceous shale, cross-bedded sandstone, bioclastic limestone and bioturbated sandstone. All these lithofacies are well-developed in the Baroch Nala section of the Surghar range except the lateritic lithofacies which contains a thin bed of ferruginous clay. In the studied sections of the Hazara basin, the lateritic lithofacies is the only well-developed lithofacies present in the area. The coal occurs at two stratigraphic levels in the Baroch Nala section. The lower coal seam is thick and its chemical study indicates higher calorific value and carbon content than the upper coal seam and with low moisture/ash content. On the basis of the calorific value, the coal of the Hangu Formation is characterized as high volatile bituminous. The degree of laterization is strong in the Langrial and Khanpur sections and moderate in Baroch Nala section.

The detail study of the Paleocene Hangu Formation consisting of sandstone, carbonaceous shale, coal, and laterite has been carried out for its source and reservoir rock potential in the Salt Range, Surghar Range, and Attock-Cherat Ranges. The TOC values of the shales range from 0.33-11.19 (2.97 wt. %) and are characterized as good to very good quality source rock except the samples from Attock-Cherat Ranges. Similarly, the free (S1) and cracked hydrocarbons (S2) amount are very small suggesting Hangu Formation as a poor source rock for free and cracked hydrocarbons except the samples from the Lumshiwal Nala. The generative potential, type of kerogen and thermal maturity calculated on the basis of TOC, S1, S2, HI, PI and Tmax all characterized Hangu Formation as fair to excellent gas or oil source, type III and mixed type III/II kerogen and immature source rock. The Hangu Formation sandstone is brownish to yellowish brown, fine to coarse grained, medium to thick bedded and massive in places. The major diagenetic changes observed in a sandstone of the Hangu Formation are; compaction, cementation, replacement and grain fracturing. The effect of mechanical compaction is more evident than that of chemical compaction. Grain contact ranges from pointed to long through sutured. The type of cement present includes silica-cement, calcite-cement, dolomite-cement, and iron-oxide cement. Silica-cement is present as both overgrowth and pore-filling cement. Clay rim is present around few grains. The process of early calcite cementation, mechanical compaction, silica, and iron oxide cementation destroys the reservoir properties of the Hangu Formation sandstone. There is no visible porosity observed except the dissolution of few grains at their margins. However, during the process of uplifting such porosity usually filled by the iron- oxide cementation. Hence, Hangu Formation is an immature source rock with a poor reservoir potential.

The Hangu Formation (Paleocene) consists of sandstone, siltstone, carbonaceous shale, coal and laterite. It is well exposed in the Trans Indus Surghar range and the southern Hazara basin. The sandstone is yellowish brown, fine to coarse grained and medium to thick bedded. The sandstone of the Hangu Formation is classified as quartz arenite on the Q-F-L diagram. It is mostly grain supported and are cemented by silica cement. The study of different stratigraphic sections reveal that Hangu Formation can be sub-divided into a number of lithofacies on the basis of sedimentary structures and lithological variations. These include lateritic lithofacies, coal and carbonaceous shale, cross-bedded sandstone, bioclastic limestone and bioturbated sandstone. All these lithofacies are well-developed in the Baroch Nala section of the Surghar range except the lateritic lithofacies which contains a thin bed of ferruginous clay. In the studied sections of the Hazara basin, the lateritic lithofacies is the only well-developed lithofacies present in the area. The coal occurs at two stratigraphic levels in the Baroch Nala section. The lower coal seam is thick and its chemical study indicates higher calorific value and carbon content than the upper coal seam and with low moisture/ash content. On the basis of the calorific value, the coal of the Hangu Formation is characterized as high volatile bituminous. The degree of laterization is strong in the Langrial and Khanpur sections and moderate in Baroch Nala section.