Volcanological evolution of Pantelleria Island (Strait of Sicily) peralkaline volcano: a review

Silvio G Rotolo,Rebecca Williams,Fabio Speranza,Stéphane Scaillet,Nina J Jordan,John C White

doi:10.5802/crgeos.51

Abstract

Pantelleria volcano has a particularly intriguing evolutionary history intimately related to the peralkaline composition of its explosively erupted magmas. Due to the stratigraphic complexity, studies over the last two decades have explored either only the pre-Green Tuff ignimbrite volcanism or the post-Green Tuff activity. We here focus on the whole evolutionary history, detailing the achievements since the first pioneering studies, in order to illustrate how the adoption and integration of progressively more accurate methods ( 40 Ar/ 39 Ar, paleomagnetism, petrography, and detailed field study) have provided many important independent answers to unresolved questions. We also discuss rheomorphism, a distinct feature at Pantelleria, at various scales and possible evidence for multiple, now hidden, caldera collapses. Although the evolutionary history of Pantelleria has shown that each ignimbrite event was followed by a period of less intense explosivity (as could be the present-day case), new geochronological and geochemical data may indicate a long-term waning of volcanic activity.

Highlights

Throughout its geologic history, the island of Pantelleria (Figure 1), the type locality of peralkaline rhy-ISSN : 1778-7025 https://comptes- rendus.academie- sciences.fr/geoscience/olitic magmatism, has been the setting for dominantly explosive volcanism
In order to appreciate fully the evolution of the volcanic stratigraphy at Pantelleria, we briefly review the history of geologic studies on this island that began with Gemmellaro [1829], who reported the results from his field surveys that he integrated with reports from contemporary naturalists
The principal aim of this paper is to review and summarize the existing volcano-stratigraphic knowledge of Pantelleria, which is otherwise scattered between pre- and post-Green Tuff (GT) papers

Summary

Introduction

Throughout its geologic history, the island of Pantelleria (Figure 1), the type locality of peralkaline rhy-ISSN (electronic) : 1778-7025 https://comptes- rendus.academie- sciences.fr/geoscience/olitic (pantelleritic) magmatism, has been the setting for dominantly explosive volcanism. The relatively low viscosity of these magmas make the pyroclastic deposits prone to rheomorphism and welding, which obscures primary textural and architectural features This peculiarity, coupled with discontinuous field exposures and a remarkably complex evolutionary history (viz., overlapping explosive events), has contributed to the difficulty in the advancement of our volcano-stratigraphic knowledge of the island. In October 1891, a submarine basaltic eruption 5 km west-northwest offshore of Pantelleria town attracted the attention of naturalist and astronomer Riccò [1892], who precisely described the evolution of the eruption, including exploding scoria at sea known as lava balloons He paid great attention to pre- and syneruptive phenomena, such as earthquake swarms, bradyseisms, and other macroseismic effects. Washington, who conducted a field campaign in 1905 and subsequently published three papers [Washington, 1913a,b, 1914] that are considered the foundation for all later studies, for the detailed geological descriptions, but especially for the in-depth discussion of the petrography of pantellerite rocks that much improved the early analytical efforts of Förstner

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