http://hdl.handle.net/123456789/24 2026-04-04T12:05:06Z 2026-04-04T12:05:06Z Hafiz Ur Rehman Kouki Kitajima John W. Valley Sun-Lin Chung Hao-Yang Lee Hiroshi Yamamoto Tahseenullah Khan http://hdl.handle.net/123456789/7802 2018-12-03T07:25:53Z 2018-01-01T00:00:00Z

Low-18O mantle-derived magma in Panjal Traps overprinted by hydrothermal alteration and Himalayan UHP metamorphism: revealed by SIMS zircon analysis Hafiz Ur Rehman; Kouki Kitajima; John W. Valley; Sun-Lin Chung; Hao-Yang Lee; Hiroshi Yamamoto; Tahseenullah Khan We report two generations of low-18O zircons from the Himalayan eclogites and their host gneisses. In situ SIMS 18O analyses on single zircon crystals (with known age and Hf isotope ratios) from two populations of chemically distinct zircons demonstrate a complex history: (1) an early low-18O mantle-derived magma, (2) followed by post-emplacement high-temperature meteoric-water alteration and finally (3) crystallization of new, low-18O minerals during the ultrahigh-pressure metamorphism. Magmatic zircon (269 Ma) in Group I eclogites yielded 18O values from 1.9 to 4.6‰ VSMOW with an average value of 4.0 ± 0.2 (n = 35, the error is 2SD analytical precision and “n” represents number of analyzed spots), which is lower than the typical mantle values (5.3 ± 0.6, 2SD). In contrast, metamorphic zircons (45 Ma) in Group II eclogites preserve unusually low, negative 18O values from −3.9 to −2.7‰ (average: −3.4 ± 0.4, n = 35, 2SD). Zircons in felsic gneiss that surround Group II eclogites have inherited magmatic cores (ca. 260 Ma) with 18O values of ca. 2.9‰, which decrease to −0.1‰ in metamorphic (ca. 45 Ma) rims. These zircons preserve lower 18O values than would be equilibrated with typical mantle. The low-18O values in magmatic zircons suggest that the mafic protolith to these eclogites formed from a hydrothermally altered subducted oceanic crust and the negative 18O values in metamorphic zircons indicate hydrothermal alteration after crystallization of the mafic magmas but before growth of metamorphic zircons. This study reports evidence for melting of subducted low-18O ocean crust to form low-18O mantle-derived mafic magmas as previously proposed by Cartwright and Valley (1991, Geology 19, 578-581) for Proterozoic Scourie Dikes.

2018-01-01T00:00:00Z Imran Khan Wasim Sajjad http://hdl.handle.net/123456789/7804 2018-12-03T07:47:43Z 2018-01-01T00:00:00Z

Morphological, biochemical and molecular characterization of culturable epilithic and endolithic bacteria from rocks of Ayubia (Murree), lower Himalaya, Pakistan Imran Khan; Wasim Sajjad Murree and Ayubia hills are parts of the lower Himalaya Mountain range in Pakistan. The rocks of these hills are younger and mostly limestone in nature. In this study, geomicrobiological investigation of the selected samples collected from Murree and Ayubia hills was carried out. The rock samples were spread on nutrient agar plates and endolithic and epilithic bacteria were isolated on the basis of colony morphology and studied further. All the isolates were screened for different industrially important hydrolytic enzymes. Study isolates were identified through 16S rRNA gene sequencing. These endoliths and epiliths were assayed for antimicrobial activities against clinical isolates S. aureus, P. aeuroginosa and E. coli. Total 31 bacterial isolates were recovered of which 15 were endolithic and 16 were epilithic. 16S rRNA gene sequencing revealed major culturable groups colonizing these rocks were clustered in four major groups, Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes which inlcude Alcaligenes, Lysinibacillus, Actinobacteria, Pseudomonas, Pusillimonas, Streptomyces, Fluviicola, Serratia, Flavobacterium, Stenotrophomonas and Brevindomonas species. The sequences were deposited in NCBI for acquisition of accession numbers. The bacterial isolates were efficient producers of oxidase, catalase, protease, amylase and gelatinase. The endolithic isolates N4 (Pseudomonas sp. KT223616) and N28 (Streptomyces sp. KT004386) exhibited good activity against all the three clinically isolated target strains. The study revealed the rocks of Murree and Ayubia hills have a rich microbial ecology that besides having an important role in weathering and mineralization processes may also be potential source of biotechnological applications.

2018-01-01T00:00:00Z M. Qasim Jan Amanullah Laghari M. Asif Khan M. Hassan Agheem Tahseenullah Khan http://hdl.handle.net/123456789/7801 2018-12-03T07:17:38Z 2018-01-01T00:00:00Z

Petrology of calc-alkaline/adakitic basement hosting A-type Neoproterozoic granites of the Malani igneous suite in Nagar Parkar, SE Sindh, Pakistan M. Qasim Jan; Amanullah Laghari; M. Asif Khan; M. Hassan Agheem; Tahseenullah Khan The Nagar Parkar area contains three distinct groups of rocks, from oldest to youngest, (1) basement rocks ranging in composition from mafic to (quartz)diorite, tonalite, granite, and younger granodiorite, (2) granite plutons similar in general features to those of the Malani Igneous Suite of Rajasthan, and (3) abundant mafic, felsic and rhyolitic dykes. The basement rocks show strong brittle and local plastic deformation, and epidote amphibolite/upper greenschist facies metamorphic overprint. The chemistry of the basement rocks contrasts the commonly agreed within plate A-type character of the Neoproterozoic granites (group 2) that are emplaced into them. The basement rock association is calc-alkaline; the granodiorite displays the compositional characteristics of adakites, whereas the tonalite has intermediate composition between typical adakite and classical island arc rocks. This paper presents detailed petrography of the basement rocks and compares their geochemistry with those of the group 2 granites as well as with rocks from other tectonic environments. It is proposed that the Nagar Parkar basement is part of a 900– 840 Ma magmatic arc that was deformed before it was intruded 800–700 Ma ago by the A-type continental granitic rocks followed by mafic to felsic dykes.

2018-01-01T00:00:00Z Muhammad Ramzan Anser Ijaz Ahmad Sabir Hussain Shah Muhammad Khubaib Abuzar Muhammad Sohail Raza Muhammad Azim Malik http://hdl.handle.net/123456789/7803 2018-12-03T07:35:32Z 2018-01-01T00:00:00Z

Weed control measures for controlling the density of Canada thistle (Cirsium arvense (L.) scop. In wheat (Triticum aestivum L.) Muhammad Ramzan Anser; Ijaz Ahmad; Sabir Hussain Shah; Muhammad Khubaib Abuzar; Muhammad Sohail Raza; Muhammad Azim Malik Canada thistle [Cirsium arvense (L.) Scop.] is a major weed in semi-arid areas of Punjab, Pakistan. studies were conducted during 2010-11 and 2011-12 at University Research Farm, Chakwal road, Rawalpindi to study Canada thistle control and density dynamics in wheat grown under contrasting environments and diverse cultural, mechanical and chemical thistle control measures. Experiments were carried out in randomized complete block design with four replications. Canada thistle density was monitored at five stages during wheat growing season. The results revealed during wet winter season, Canada thistle was effectively controlled (90-97%) when dry-season tillage was integrated with fertilizer placement in a strip along crop row and with single application of full dose of clopyralid. The drier winter season witnessed significant thistle control (91%) with half dose of clopyralid when integrated with dry-season tillage, fertilizer placement followed by inter-row cultivation and remained at par with experimental treatment where full dose of clopyralid was applied. The thistle dynamics data showed that higher thistle re-sprouting during wetter environment decreased efficiency of thistle control in cultural and mechanical control measures applied either in integrated or sole fashion.

2018-01-01T00:00:00Z