The development of the Deception Island volcano caldera under control of the Bransfield basin sinistral strike-slip tectonic regime (NW Antarctica).

LOPES F. C.; CASELLI A.T.; MACHADO A.; BARATA T.

Antofagasta

Congreso; XIII Congreso Geológico Chileno; 2012

The distribution and orientation of fracture systems that affect Deception Island, and the elongated geometry of its volcanic caldera, a horseshoe-shaped slightly warped in sigmoid, with the major axis oriented NW-SE, are typical of a Riedel model induced by a regional left-lateral simple shear zone. It is suggested that this caldera was formed by a volcano-tectonic process above a magma chamber stretched under the control of the regional transtensional regime. The folds that affect the glacier in the eastern flank of the island, which are visible along the Costa Recta shore-line, may have been induced or favoured by this deformation.