gohar rehman

This study aims at evaluating the utilization of carbonate rocks from the Bampokha (Nikanai Ghar Formation) and Sawaldher (Kashala Formation) areas in different industries. Two varieties from the Nikanai Ghar Formation, known under the trade names as Super-white and Sunny-grey, are selected for petrographic and geochemical analysis to evaluate these as a source of calcite (CaCO3), in chemical industries. Petrographically, both the varieties from Bampokha area, are calcitic marbles that exhibit heteroblastic mosaic texture. Geochemical data coupled with X-ray diffraction and petrographic analysis confirms that the Super-white variety is very high purity marble and hence meets the specifications for different chemical industries such as iron and steel industry, glass manufacturing, flue gas desulphurization, soda ash manufacturing and water purification and effluent treatment. In contrast, the high silica (4.1 wt.%) and low calcite contents (<95 wt.%), render the Sunny-grey unsuitable for chemical industries. The rock from Sawaldher quarry, exhibiting an interlocking mosaic pattern, is calcitic marble. Minor amounts of quartz, muscovite and opaque minerals also occur. Comparing the physico-mechanical properties of the aggregate from Sawaldher marble with time-honoured international standards suggests its suitability in concrete work with ordinary portland cement and asphalt. The concrete mix, designed for Class D2 concrete, has an average 28-days compressive strength value of 518 kg/cm2 and thus well above the minimum targeted strength of 425 kg/cm2 for the mentioned class, and hence further endorses that the aggregate can produce strong concretes. This study also suggests the utilization of the studied carbonate resources on industrial scale.

The Kohat Foreland Basin is an outcome of continental collision between Indian and Eurasian plates defining the southern edge of Himalayan Orogenic System in the north-western Pakistan. This study constrains the structural geometry and kinematics in 2-D and 3-D workflow, evaluation of the role of multiple detachments and the structural correlation between surface and sub-surface geology of the western Kohat Foreland Basin. The structural style of the western Kohat Foreland Basin evinces the thin skin deformation associated with a couple of structural detachments i.e.i) base-Eocene shale/ evaporite sequence ii) the upper interface of crystalline basement. These detachments separate the outcropping and buried stratigraphic sequence of the Kohat Foreland Basin into upper and lower structural-stratigraphic domains. The lower domain has a series of north-dipping or south-verging fold-thrust assemblages incorporating a rigid rock sequence of EoCambrian to Paleocene. The comparatively more ductile rocks of the upper domain comprising of Eocene to Pliocene are deformed into tight, overturned, doubly plunging and internally faulted anticlines intervened by broad synclines. The two domains dictate different deformational behaviour and structural style, deforming in total disharmony; hence the structural geometry of shallow units does not match the sub-surface rocks. The total 37% of shortening in the sedimentary cover was revealed by structural balancing in 2-D and 3-D kinematic modelling. Stress analysis of Gurguri Fault unveiled 40% failure susceptibility and recorded positive values of effective normal stress (σn) with an orientation of maximum principle stress (σ1) as N17°.