We here report 3 occurrences of rock fulgurites: 2 at Tor Zawar, Ziarat District, and 1 at Jang Tor Ghar, Muslim Bagh, Pakistan. The first and second melting events occurred at Tor Zawar, Ziarat on 27 January 2010, and sometime during the month of January 2011; the third melting event occurred on 12 February 2011. All these events occurred near the base of steel pylons of electric transmission lines installed on hillside outcrops, which transmitted atmospheric lightning to the outcrop. At Tor Zawar, Ziarat District, the pylons are installed on outcrops of the volcanogenic conglomerate of the Late Cretaceous Bibai Formation, whereas, in the Jang Tor Ghar, Muslim Bagh, they are constructed on alluvium mostly comprising ultramafic fragments of the Muslim Bagh Ophiolites. The lightning strikes transmitted enough energy to partially melt the outcrops near the bases of the steel pylons. The melt solidified to produce light brown to black vesicular basaltic glass that is partly devitrified.
Abstract The Ordovician and Silurian successions between Falahill and Galashiels encompass six flysch-dominated formations: the Upper Ordovician Portpatrick and Shinnel Formations representing the Leadhills Group, the Llandovery Mindork, Garheugh, and Buckholm Formations together comprising the Gala Group, and a formation indeterminate of age within the Hawick Group. Southward ensialic andesitic volcanic arc and northward low- to medium-grade sialic sources contributed sediment, whilst ophiolitic and subduction-related sources made minor contributions. Deposition took place firstly, in a SE-migrating back-arc basin bordering the northerly source, the Laurentian continent. Subsequent NW-directed underthrusting led to formation out of the back-arc basin of an imbricate thrust stack which migrated southeastwards. Ultimately a foreland successor basin formed ahead of the rising thrust stack. Flysch units are typically associated with linear outcrops of Moffat Shales which are the loci of major steep SE-translating reverse faults, two of which participate in a late-stage sinistral strike–slip duplex with large-scale imbrication. The faults divide the succession into a sequence of tectonostratigraphic blocks, successively younger to the SE. At least six of the ten blocks customarily recognised in the Southern Uplands, Blocks 3–8, are represented, some of which coincide with single or complete formations.
Abstract An article by A. C. Kerr and coworkers published in 2010 in Mineralogical Magazine (74, 1027–1036), reviewed an event that was interpreted as the eruption of a basaltic flow on 27th January 2010, at Tor Zawar, Ziarat, Pakistan. The regional and local geology, volcanological aspects, petrography and major-element and trace-element analyses of two samples were presented. On the basis of these data it was proposed that this was a magmatic event and that the lava was derived from the mantle. On the basis of our extensive field work in the this area, and observations at the site of another similar incident that happened almost a year later (in January 2011) ∼300 m north of the first locality, we wish to clarify the geological context and propose an alternative origin. Our field observations suggest that both events were the result of localized surface melting at the base of metal electricity pylons, and their associated steel cable supports. The metal pylons and cable supports provided a path to earth for lightning discharges into the volcanic conglomerate of the Late Cretaceous Bibai Formation. We propose that this transmitted sufficient energy to melt the outcrop. We disagree with the proposal that the 'lava flows' at Tor Zawar were magmatic events and that the rocks formed are derived from the mantle. Alternatively, we propose that these 'lavas' were produced in a manner similar to fulgurites.
Abstract Abstract The lithostratigraphy, biostratigraphy and depositional environments of the Cretaceous successions Pakistan were investigated to reveal the major geological events, including local, regional and global scale tectonics, phases of volcanism, basin condensation, emergence of structural highs and episodes of non-deposition. The succession is entirely missing at Salt Range, but were excellently exposed in Kirthar-Sulaiman Fold-Thrust belts. Such deviating nature (e.g., Hazara, Kalla Chitta, Surghar & Kohat) suggesting episodical tectonic activities were associated with inter-intra rifting and drifting of the India-Madagascar-Seychelles and Antarctica-Australian Plates during Cretaceous time. Correspondingly, several unconformities within the Cretaceous succession at numerous stratigraphic intervals consistently attest the effect of tectonics throughout the period. The recognized unconformities over Kawagarh, Lumshiwal, Parh and Fort Munro formations testify episodic uplifts on local and/or regional scales during the Coniacian-Santonian, Coniacian-Maastrichtian, Campanian and Maastrichtian in response to the separation of Madagascar from the India-Seychelles plate. In contrast, there was continuous sedimentation of carbonate, clastic and/or submarine volcanics in the Kirthar and Indian-Eurasian suture zone. Significant geological events in the restricted regions e.g., local scale submarine volcanism (Bibai Formation), ironstone deposition (Dilband Formation) and basin condensation (Khuzdar) were also associated with such rifting-drifting phases along the WNW margin of the Indian Plate.
Resume Une premiere etude magnetostratigraphique a ete realisee sur les unites appartenant aux formations fluviatiles neogenes du bassin de Rudgai (Sibi) dans la chaine du Sulaiman, avant-pays de l'Himalaya. Cinquante-neuf echantillons ont ete preleves le long d'une coupe, sur 400 m d'epaisseur, et traites en laboratoire, afin de dater plus precisement ces unites et de mettre en evidence les implications tectoniques de formation de ce bassin. Les resultats montrent qu'une seule correlation est possible entre la stratigraphie de polarite magnetique obtenue et l'echelle de polarite magnetique de reference. Cela permet de resituer la sequence etudiee entre 16,5 et 14,8 Ma, de mettre en evidence la diachronie des sediments molassiques entre les bassins du Rudgai (Sibi) au sud (16.5 Ma) et ceux de Potwar au nord (10,1 Ma).
Abstract The lithostratigraphy, biostratigraphy and depositional environments of the Cretaceous successions in Pakistan were investigated to reveal the major geological events, including local, regional and global-scale tectonics, phases of volcanism, basin condensation, emergence of structural highs and episodes of non-deposition. The succession is entirely missing at Salt Range but is excellently exposed in the Kirthar–Sulaiman Fold-Thrust belts. Such deviating nature (e.g. Hazara, Kala Chitta, Surghar and Kohat), suggesting episodical tectonic activities, is associated with inter–intra rifting and drifting of the India–Madagascar–Seychelles and Antarctica–Australian plates during the Cretaceous. Correspondingly, several unconformities within the Cretaceous succession at numerous stratigraphic intervals consistently attest to the effect of tectonics throughout the period. The recognized unconformities over Kawagarh, Lumshiwal, Parh and Fort Munro formations testify to episodic uplifts on local and/or regional scales during the Coniacian–Santonian, Coniacian–Maastrichtian, Campanian and Maastrichtian in response to the separation of Madagascar from the India–Seychelles Plate. In contrast, there was continuous sedimentation of carbonate, clastic and/or submarine volcanics in the Kirthar and Indian–Eurasian suture zone. Significant geological events in the restricted regions, e.g. local-scale submarine volcanism (Bibai Formation), ironstone deposition (Dilband Formation) and basin condensation (Khuzdar), were also associated with such rifting–drifting phases along the WNW margin of the Indian Plate.