Muhammad Amjad Sabir

Stratigraphic and sedimentological attributes in Hazara Basin Lesser Himalaya, North Pakistan: their role in deciphering minerals potential

Hazara Basin lies within lesser Himalayan region and has undergone complex depositional and tectonic episodes responsible for accumulation of different economic minerals. Phosphate, ironstone, manganese, coal and china clay deposits reported from the area indicate different sedimentary environments including deep marine to carbonate and clastic shallow marine, glaciogenic and fluvial systems. These variable environments were mainly a result of different tectonic events, which were caused by formation and rifting of Rodina, Gondwana, Pangaea, India, Madagascar and collision of India with Eurasia. Phosphate was formed in anoxic shallow marine environments during Cambrian in Sirban Member and Hazira Formation, whereas, ironstone deposits were formed in oxygenated shelf and/or residual mechanisms during nondepositional periods, e.g., at the base of Jurassic and Tertiary successions. China clay was also formed at unconformable surface at the base of Shinwari Formation of Jurassic age. Coal within Chichali Formation was formed in anoxic, organic-rich deltaic shelf conditions. Basin evolution combined with stratigraphic set up of the region has played very important role in formation and exploration of these economic mineral deposits.

An efficient time-stepping scheme for numerical simulation of dendritic crystal growth

In this article, we present an adaptive time-stepping technique for numerical simulation of dendritic crystal growth model. The diagonally implicit fractional step -scheme for time discretisation and conforming finite-element method for space discretisation are used. The performance of the scheme is illustrated by simulating two-dimensional dendritic crystal growth problem, allowing the comparison with other numerical methods. In addition, traditional diagonally implicit Runge–Kutta method is used and comparison is given with the proposed scheme. Robustness is observed for the present scheme. Parametric effects on the growth and shape of dendrites are also given.

Geochemical attributes of late Neoproterozoic Salt Range Formation, Pakistan: constraints on provenance, paleoclimate, depositional and tectonic settings

Detailed geochemical analyses of clastic fraction of the oldest exposed Salt Range Formation in the famous salt producing region (Salt and Trans-Indus Ranges) Pakistan was carried out in order to understand provenance, paleoclimate, depositional and tectonic settings. Sandstone and shale samples of Salt Range Formation were analysed for major, trace and Rare Earth Elements and various geochemical models and ratios were used to interpret. Geochemical analyses of both sandstone and shale fraction mostly display similar results and interpretations. The samples are classified as arkose, subarkose, litharenites and were sourced from felsic and/or intermediate igneous rocks. The sedimentation of the detritus was occurred in fluvial to restricted shelf conditions under arid to semi-arid and oxygenated climate conditions. The tectonic settings of the sediments were mainly Oceanic and Continental Island arcs as well as Active Continental margin.

Assessment of heavy metals concentration in phosphate rock deposits, Hazara basin, Lesser Himalaya Pakistan

Naturally occurring phosphate rock is the only essential source for the production of fertilizers. Heavy metals and phosphate concentrations are quite higher in phosphate rock formed by sedimentary processes. This detail study was conducted to evaluate the heavy metal concentrations in part of the Hazara region, which is the only source of phosphate fertilizer in the country. Heavy metals are considered as one of the main pollutant responsible for environmental contamination of soil. This study included the concentration of phosphorite in the Hazara region in the three useful forms: total phosphorite, extractable phosphorite and water soluble forms. The phosphorous extracted from sedimentary deposits used to maintain the natural content in agricultural soil which was being depleted due to the regular practice of crop harvest. The data collected during this studies were statically analyzed which refers the significant variations in P, Zn, Cr, Mn, As, Cu, Fe, Ni, & Pb. Zn and Cr concentration in Hazara phosphates. Heavy metals for instance Pb, Cr, Zn and Cu present in higher amount than usable limits and may create environmental pollution (air, surface & groundwater and soil) and health issues of humans. Therefore it is recommended that managing remedial steps are necessary around the mining regions to avoid environmental and health issues.

Comparative Studies on the Use of Binary and Ternary Combinations of Various Acidifying Agents for the Reduction of Soil pH

ABSTRACT The present study deals with the effects of addition of sulfur along with other acidifying agents for their ability to lower and maintain the pH in a given range for a longer period of time. The chemicals were subjected to batch test individually and in combinations. Treatments were applied to three soils of different textures: sandy clay loam, clay loam, and silt loam. A 1:1 soil/water paste along with the added amendment was maintained at room temperature for 2 months. Most of the chemical treatments lowered the pH significantly. Combinations containing S/Al2(SO4)3/H2SO4, S/Al2(SO4)3/H2O2, and S/H2O2/H2SO4 were found to be very effective in lowering the pH. The soil pH remained acidic for 2 months, indicating the suitability of chemically amended soil for the plantations requiring acidic soil pH.