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

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 faults, while mesostructural data show a more complex pattern which is characterized by four systems of discontinuity. The volcanological features show a marked difference between a north western sector characterized by products of a basaltic nature and a south central one in which evolved products connected with the presence of a magmatic chamber are present. The present‐day stress field, as derived from structural analysis, is characterized by a maximum compression oriented NNW‐SSE which allowed the activation of right‐lateral strike‐slip faults bordering the Pantelleria trough giving rise to a thinning of the underlyng crust. Inside this main dextral shear zone it is possible that the development of pull‐apart basins bounded by N‐S trending normal faults could generate further thinning of the already thinned out crust zone and give rise to the magmatic phenomena known to occur mostly along the N‐S trending extension structures. Such a model would therefore help to understand the characters of the volcanism associated with a zone of continental collision as well as its distribution, which is not rigorously in accordance with a classical rifting process.