Transtensive tectonics in the Strait of Sicily: Structural and volcanological evidence from the Island of Pantelleria

Abstract

A detailed structural analysis carried out on the volcanic products of the island of Pantelleria has shown that the large-scale setting is dominated by N-S trending normal faults and NW-SE right-lateral strike-slip

Late Quaternary deformation on the island on Pantelleria: New constraints for the recent tectonic evolution of the Sicily Channel Rift (southern Italy)

“…A statistic analysis of the total minor fracture measurements collected at selected sites shows that the dominant set affecting the products of the island is oriented along a roughly NNE-SSW direction with a mean direction of A c c e p t e d M a n u s c r i p t N 15°E (Figure 4c). This set is constituted by sub-vertical systematic extensional joints characterized by spacing ranging from a few decimetres to 1 m; they are frequently represented by open fractures filled by secondary material and locally marked by fumarolic activity (Cello et al, 1985). In place, at both large and small scales, this set appears to be constituted by pairs of conjugate hybrid joints that define the dihedral angles containing the shortening and the extension directions.…”

“…Volcanic horizons exposed on small sections along the southern coastal cliff of the island on relics of palaeo-escarpments attributed to La Vecchia caldera rims, constrains the age of this volcano-tectonic collapse to between 175 ka and 106 ka (Mahood and Hildreth, 1986). The more recent Zichidi Caldera (Cello et al, 1985), that corresponds to the Monastero Caldera of Cornette et al (1983) and to the Cinque Denti Caldera of Mahood and Hildreth (1983), exhibits well developed rims that, extending more or less continuously, define a sub-circular subsided area located on the central portion of the island inside the older Serra Ghirlanda Caldera (Figure 2). The Zichidi Caldera rim is well preserved along the eastern side of Piano di Ghirlanda, along the Costa Zichidi and to the north of Bagno dell'Acqua from the Khartibucale ridge and Cala Cinque Denti.…”

“…The most impressive feature is constituted by a caldera complex formed by two large nested calderas that developed on the south-eastern portion of the island (Figure 2). The oldest caldera, named La Vecchia Caldera by Mahood and Hildreth (1986) or Serra A c c e p t e d M a n u s c r i p t Ghirlanda Caldera by Cello et al (1985), is defined by a of 2 km-long remnant rim that, completely mantled by the  45 ka-old Green Tuff, bounds to the west, with a maximum height of 100 m, the arc-shaped Serra Ghirlanda ridge. Volcanic horizons exposed on small sections along the southern coastal cliff of the island on relics of palaeo-escarpments attributed to La Vecchia caldera rims, constrains the age of this volcano-tectonic collapse to between 175 ka and 106 ka (Mahood and Hildreth, 1986).…”

“…The structures of the Sicily Channel have been interpreted as an intraplate rift related to the NE directed displacement of the northern part of the Pelagian Block including Sicily, away from the Africa continent (Illies, 1981;Winnock, 1981;Beccaluva et al, 1983;Finetti, 1984;Corti et al, 2005). The tectonic depressions of the Sicily Channel have also been interpreted as large and discrete pull-apart basins involving deep crustal levels that developed in front of the Africa-Europe collisional belt within a large dextral wrench zone (Cello et al, 1985;Jongsma et al, 1985;Reuther and Eisbacher, 1985;Ben-Avraham et al, 1987;Boccaletti et al, 1987;Cello, 1987;Reuther, 1990;Finetti and Del Ben, 2005). A further interpretation is proposed by Argnani (1990) who suggests that the rifting is due to mantle convections developing during the rollback of the African lithosphere beneath the Tyrrhenian basin.…”

Sequential growth of deformation bands in carbonate grainstones in the hangingwall of an active growth fault: Implications for deformation mechanisms in different tectonic regimes

“…1). The WNW-trending Pantelleria Rift (or Sicily Channel Rift Zone) is c. 100 km wide and 600 km long (Grasso et al, 1986) and developed from late Oligocene times until Messinian times (Cello et al, 1985). The Pantelleria Rift developed in response to extension localizing in the central part of the Pelagian block, between Tunisia and Sicily, likely driven by back-arc N-S-directed extension related to Apennine-Maghrebian shortening (Argnani, 1990).…”