A recent hydrocarbons discovery in 2021 in the Kawagarh Formation has brought attention to the significance of sedimentology and specifically diagenesis for understanding and characterizing the reservoir properties. The diagenetic history and multiscale processes that contributed to diagenesis were vaguely known. This study aimed to reconstruct various diagenetic phases, paragenetic sequences, and the interrelationship of these phases in the Kawagarh Formation. The diagenetic processes were identified and characterized through an integrated methodology utilizing the outcrop, petrographic, and geochemical analyses. Early calcite cementation was found to occur in the early stages of marine burial diagenesis involving pore fluid originating from the dissolution of aragonite in interlayer marl/mudstone beds and reprecipitating as microspar in adjacent limestone beds. The absence of mechanical compaction in wackstone and mudstone facies and the presence of late compaction in lithified packstones clearly imply that early calcite cementation occurred prior to compaction. Dolomitization with stylolites coupled with significant negative oxygen (δ¹⁸O) isotope values implies a fault-related hydrothermal dolomitization model. Uplift introduced the fractures and low Mg fresh fluids to the system which caused calcitisation in shallow burial settings. The depleted δ¹³C and negative δ¹⁸O values indicate the mixing of surface-derived waters with hot burial fluids during the calcitization. This study offers valuable insights into several aspects related to the formation and the basin itself, including burial depths, fluid influx, and geochemical gradients. It also sheds light on the evolution of reservoir properties such as porosity and permeability in dolomitization fronts. Such insights can be used to gain a deeper understanding about the burial history, basin evaluation, and reservoir characterization for hydrocarbon exploration.

Quality of aggregate material reflects the physical, chemical and mineralogical properties of source rock. Limestone is main source of crushed rock aggregate, which is largely used by construction industry. There are few geological formations in Kohat-Potwar province which qualify the specific criteria for utilization as aggregate in building material. Khairabad Limestone exposed in Kalabagh area in Western Salt Range contains colossal quantity of minable aggregates. That’s why, we quantitatively examined this limestone of Paleocene age through several physical, chemical, mineralogical, engineering and mechanical tests to evaluate its aptness as aggregate material. AASHTO, ASTM, BS and NHA designated engineering tests including Los Angles Value (26.59%), Aggregate Impact Value (13.91%), Aggregate Crushing Value (12.84), soundness value (1.84%), coating and stripping of bitumen (96.4%), specific gravity (2.7), water absorption (0.83%), unit weight (1.65 g/cm3), total (elongation + flakiness) index (22.78%), and petrographic analysis (ASR & ACR) revealed that it is highly feasible aggregate resource with suitable properties. Investigated reserve is vast and thick enough to provide aggregate material to nearby local construction as well as national megaprojects. It would be a good contribution to the rising demand of construction materials in the country.

In Hazara Basin, Early Eocene is represented by carbonate succession of Chorgali Formation which is mainly composed of limestone with marls and calcareous shale. Limestone is predominantly marly and argillaceous in nature. Two Stratigraphic sections of Chorgali Formation exposed at Gharaga and Bhattian villages have been completely examined and sampled for outcrop characteristics, petrography, microfacies and depositional settings. These sections have both well preserved lower and upper contacts with Early Eocene Margalla Hill limestone and Middle Eocene Kuldana Formation, respectively. The petrographic analyses reveal that Chorgali Formation exposed at Gharaga and Bhattian sections yields abundant Eocene foraminifers along with other fauna and their broken shells. On basis of outcrop data and detailed petrographic analyses, five microfacies are recognized including Nummulites-Lockhartia wackestone to packstone (MF-1), Nummulites- Assilina wackestone to packstone (MF-2), Ostracods-Miliolids packstone (MF-3), Marls Microfacies (MF-4) and Calcareous shale Microfacies (MF-5). Comprehensive microfacies, palaeoecological and outcrop data reveal that deposition of Chorgali Formation was occurred on mid ramp settings with some deposition in attached to partially restricted lagoonal area of inner ramp and proximal part of outer ramp.

The series of strike-slip faults, dissecting the axes of folds and traces of thrusts, have created lateral off-sets ranging from a few to hundreds of meters in the southern part of the Raskoh Range in Pakistan. The Early Eocene Kharan Limestone stretches along the fault planes of these faults whereas the shale and interbedded sandstone/conglomerates of the underlying and overlying formations cut and truncate against the body of stretched limestone. The relationship of the structural elements reveals that the strike-slip faults represent the latest episode of structural deformation in the area, and these could have been developed when the Kharan Limestone was presented at a very shallower depth due to erosion of overlying formation during uplift. The major set of the strike-slip faults, having orientation of NNE‒SSW and along which Kharan limestone stretches, is parallel to the Chaman Fault—a tectonic plate scale transform fault, located to the east of the Raskoh Range. The movement along Chaman fault occurred slowly by displacing the Indian Plate to its east and creating strong continuous strain to its west where the study area is located. We believe that the stretching of Kharan Limestone along fault planes is likely the result of the slow and steady displacement along the strike-slip faults. The time-dependent deformation i.e., brittle creep is interpreted as the main phenomenon along with the minor role of plastic/ductile deformation that have created stretching of the Kharan Limestone.