Siddiqui R.H.,Geoscience Advance Research Laboratories |
Qasim Jan M.,University of Peshawar |
Asif Khan M.,University of Peshawar
Journal of Asian Earth Sciences | Year: 2012
The Raskoh arc is about 250km long, 40km wide and trends in an ENE direction. The oldest rock unit in the Raskoh arc is an accretionary complex (Early to Late Jurassic), which is followed in age by Kuchakki Volcanic Group, the most wide spread unit of the Raskoh arc. The Volcanic Group is mainly composed of basaltic to andesitic lava flows and volcaniclastics, including agglomerate, volcanic conglomerate, breccia and tuff, with subordinate shale, sandstone, limestone and chert. The flows generally form 3-15m thick lenticular bodies but rarely reach up to 300m. They are mainly basaltic-andesites with minor basalts and andesites. The main textures exhibited by these rocks are hypocrystalline porphyritic, subcumulophyric and intergranular. The phenocrysts comprise mainly plagioclase (An 30-54 in Nok Chah and An 56-64 in Bunap). They are embedded in a micro-cryptocrystalline groundmass having the same minerals. Apatite, magnetite, titanomagnetite and hematite occur as accessory minerals.Major, trace and rare earth elements suggest that the volcanics are oceanic island arc tholeiites. Their low Mg # (42-56) and higher FeO (total)/MgO (1.24-2.67) ratios indicate that the parent magma of these rocks was not directly derived from a mantle source but fractionated in an upper level magma chamber. The trace element patterns show enrichment in LILE and depletion in HFSE relative to N-MORB. Their primordial mantle-normalized trace element patterns show marked negative Nb anomalies with positive spikes on K, Ba and Sr which confirm their island arc signatures. Slightly depleted LREE to flat chondrite normalized REE patterns further support this interpretation. The Zr versus Zr/Y and Cr versus Y studies show that their parent magma was generated by 20-30% melting of a depleted mantle source. The trace elements ratios including Zr/Y (1.73-3.10), Ti/Zr (81.59-101.83), Ti/V (12.39-30.34), La/Yb. N (0.74-2.69), Ta/Yb (0.02-0.05) and Th/Yb (0.11-0.75) of the volcanics are more consistent with oceanic island arcs rather than continental margin arcs. It is suggested that the Raskoh arc is an oceanic island arc which formed due to the intra-oceanic convergence in the Ceno-Tethys during the Late Cretaceous rather than constructed on the southern continental margin of the Afghan block, as claimed by previous workers. It is further suggested that the Semail, Zagros, Chagai-Raskoh, Muslim Bagh, and Waziristan island arcs were developed in a single but segmented Cretaceous Ceno-Tethyan convergence zone. © 2012 Elsevier Ltd.
Haider N.,Geoscience Advance Research Laboratories |
Khan S.,Geoscience Advance Research Laboratories |
Ali A.,University of Peshawar |
Ali L.,University of Peshawar
Arabian Journal of Geosciences | Year: 2016
The Pliocene-Pleistocene Ghari Chandan Formation consists of lacustrine-fluvio-deltaic deposits exposed in the Attock-Cherat Range. Three beds of bentonite deposits occur in the upper part of the formation. An average thickness of each layer ranges from 0.4 to 1 m with a total strike length of ~5 Km. Montmorillonite and saponite clay minerals with admixtures of quartz, feldspar, muscovite, biotite, and hornblende were identified in these samples. Compositionally these beds are similar and comprised of dioctahedral smectite. The differential thermal analyses of bentonite reveals high thermal stability of the deposits. Detailed mineralogical and geochemical investigations suggest that the Garhi Chandan deposit is a mixture of calcic and sodic bentonite derived from andesitic and trachyandesitic source rock. Heavy metal concentration reduces the overall adsorbing capacity of the deposit. © 2016, Saudi Society for Geosciences.
Abbas Bukhari S.Z.,University of Wah |
Chaudhry A.H.,University of Wah |
Chaudhry A.H.,Geoscience Advance Research Laboratories |
Iqbal M.N.,University of Wah |
Siddiqui R.H.,Geoscience Advance Research Laboratories
Kemija u industriji/Journal of Chemists and Chemical Engineers | Year: 2013
The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplementary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM). The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced.
Siddiqui R.H.,University of Balochistan |
Jan M.Q.,University of Peshawar |
Kakar M.I.,University of Balochistan |
Kakar E.,University of Balochistan |
Haider N.,Geoscience Advance research Laboratories
Arabian Journal of Geosciences | Year: 2016
The Juzzak Sill occurs in the western part of the east-west trending, subduction-related magmatic belt known as the Chagai arc. The sill is concordantly emplaced in the Paleocene Juzzak Formation and locally cross-cuts the Early to Middle Eocene Robat Limestone and Eocene Saindak Formation. The sill is a porphyritic pyroxene diorite that grades into a porphyritic andesite (60.12–61.57 wt% SiO2) along the chilled margins. It comprises phenocrysts of hypersthene and plagioclase (An32–45) in a medium- to fine-grained groundmass of these minerals, opaque oxide, and apatite. The rocks are high-K (2.37–2.86 wt% K2O) calc-alkaline with low Mg# (42–55), Cr (51–80 ppm), and Ni (22–30 ppm) contents. Mantle-normalized trace element patterns, exhibited by marked negative Nb anomalies and positive spikes for Sr, Rb, and Zr and are akin to island arc signatures. The relatively higher ratios of Zr/Y (3.57–6.58), Ti/V (46.05–54.36), Ta/Yb (0.14–0.15), and Th/Yb (2.56–2.65) and high 87Sr/86Sr ratio (0.70524) suggest the role of continental crust materials, thus implying continental margin-type arc affinity. The source diagnostic ratios including K/Ba, P/Zr, and La/Ce of Juzzak Sill andesite and Eocene andesite from the Chagai arc are more or less similar, but the former has a much higher K/Y and Ba/Y ratios, which suggests assimilations of the host sediments during intrusion. © 2016, Saudi Society for Geosciences.
Khan M.D.,Quaid-i-Azam University |
Hameed S.,Quaid-i-Azam University |
Haider N.,Geoscience Advance Research Laboratories |
Afzal A.,King Fahd University of Petroleum and Minerals |
And 4 more authors.
Materials Science in Semiconductor Processing | Year: 2016
In this work, we report the results of deposition of PbS thin films using single molecular precursor, bis(O-isobutylxanthato)lead(II), in the presence of additives namely: sodium dodecyl sulfate (SDS), Tween and Triton x-100, via aerosol assisted chemical vapor deposition (AACVD). The as-deposited PbS thin films are highly crystalline and exhibited superior adhesion to glass substrates. Powder X-ray diffraction (XRD) analysis confirmed the formation of pure cubic phase of PbS. Thin films deposited using 0.4 mM Triton X-100 as additive resulted in wire like structures while 0.8 mM Triton X-100 deposited thin films comprised of predominantly shoe shaped structures. Further, increase in concentration (1.2 mM) of Triton X-100 deposited films having rod like morphology. The scanning electron microscopy (SEM) confirmed that in the presence of SDS, thin films consist of spherical shaped crystallites. Energy dispersive X-ray spectroscopy (EDX) and X-ray photon electron microscopy (XPS) of as-deposited PbS thin films was used to study chemical composition of thin films. © 2016 Elsevier Ltd. All rights reserved.
Ashraf S.,Quaid-i-Azam University |
Saeed A.,Quaid-i-Azam University |
Malik M.A.,University of Manchester |
Florke U.,University of Paderborn |
And 3 more authors.
European Journal of Inorganic Chemistry | Year: 2014
Herein, we describe the synthesis and characterization of new ligands, N,N-diethyl-N′-(1-naphthoyl)thiourea (1a) and N,N-dipropyl-N′-(1- naphthoyl)thiourea (1b), and their complexes with copper, bis[N,N-diethyl- N′-(1-naphthoyl)thioureato]CuII (2a) and bis[N,N-dipropyl- N′-(1-naphthoyl)thioureato]CuII (2b). All four compounds (i.e., 1a, 1b, 2a, and 2b) were characterized by elemental analysis, 1H NMR and 13C NMR spectroscopy, and FTIR spectroscopy. The structures of compounds 1a, 1b, and 2b were determined by single-crystal X-ray diffraction analysis. Thermogravimetric analysis of 2a and 2b showed that both compounds decompose between 190 and 370 °C. Compounds 2a and 2b were then used as single-molecular precursors for the deposition of copper sulfide thin films through aerosol-assisted chemical vapor deposition. The phase and purity of the as-deposited thin films were confirmed by powdered X-ray diffraction, which showed that the as-grown films were composed of the orthorhombic (Cu 7S4) phase only. Morphological studies of the as-deposited films were performed by using field-emission scanning electron microscopy. The elemental composition of the thin films was determined by energy-dispersive X-ray spectroscopy. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.