Brittle tectonic structures and palaeostress analysis in the Isle of Wight, Wessex basin, southern UK

Brittle tectonic analysis of Cretaceous-Paleogene sediments at a total of 1 7 sites located in the Isle of Wight (U.K.) enables four main tectonic even ts that occurred prior to and after the folding to be identified and succes sive palaeostress tensors to he determined using the inversion method. Thre e of the events can he shown to have occurred prior to the folding: (1) a s yn-sedimentary extension of Upper Cretaceous age; (2) a strike-slip faultin g regime with an ESE-WNW direction of compression: (3) a compressional regi me, marked by strike-slip faulting, with an NNE-SSW to N-S direction or com pression. The fourth and last compressional event took place after the fold ing and is characterised both by reverse and strike-slip faulting, with a d ominant N-S direction of compression. Syn-folding faults also developed bet ween the third and fourth events. All four events can be connected to the e xtensional tectonics and different steps of structural inversion. both of w hich were integral to the development and evolution of the Wessex basin. (C ) 2001 Elsevier Science Ltd. All rights reserved.