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.

You do not currently have access to this article.