Petrographic Analysis and physico-mechanical Properties of Nikanai Ghar Formation, Swabi, North-western Pakistan

The petrographic analysis and physico-mechanical assessment of the Nikanai Ghar Formation, exposed in the vicinity of the Bando Obo marble, near Swabi Town, north-western Pakistan, were carried out to assess and look into its prospects to serve as a building stone for engineering projects. Nine fresh bulk samples representing different textural types were chosen to investigate petrographic properties, as well as the physical and mechanical behaviour of the Nikanai Ghar Formation. A series of geotechnical tests and petrographic analyses were carried out to assess the material's suitability for construction applications. These geotechnical tests included measurements of unconfined compressive strength (UCS), Unconfined tensile strength (UTS), specific gravity (SG), shear strength (SS), porosity, and water absorption. The obtained physical qualities were then compared to standard specifications to evaluate their appropriateness for use in construction. The analysed samples are divided into different textural and mineralogical categories based on a careful microscopic examination of three representative thin sections. Four of the samples, JTN-1, JTN-2, JTN-4, and JTN-7, have a striking mineralogical similarity, both consisting primarily of calcite with only traces of opaque ore minerals. However, their textures are different, i.e., shape, grain size, and grain boundaries. JTN-2, JTN-9, and JTN-8 samples are medium-grained and sub-equi-granular while JTN-1, JTN-4, and JTN-5 are predominantly fine-grained and equi-granular. The JTN-3, JTN-6, and JTN-7 Samples are coarse-grained and sub-equi-granular to granular and contain trace amounts of muscovite, rutile, and ilmenite. The analysis showed that the Nikanai Ghar Formation can be used as aggregates by the domestic building sector because it falls within the parameters of standard specifications.