Use of Landsat and Seasat data as a tool in kinematic analysis: The Tunisian Atlas

Brittle and plastic deformations of the Tunisian Atlas were studied using Landsat data, Seasat synthetic aperture radar (SAR) data and field surveys. Locations of structural stations were guided by detailed analysis of images and computer compatible tapes (CCTs). Digital processing and enlargements at scales of 1:100000 and 1:200 000 allowed the recognition of several fault displacements and strata dips, followed by field checks. This paper presents an original and complete structural map of the Tunisian Atlas for the first time, showing the en echelon pattern of the major folds and the numerous fault systems. The kinematic evolution of the Tunisian Atlas is shown through the integration of remotely-sensed, microtectonic and focal mechanism data. Circular folds, Riedel shears, reverse and tear faults in the Northern Atlas and asymmetrical folds and strike-slip and reverse faults in the Southern Atlas are framed in a new model involving wrench tectonic and induced transpression. Four principal deformational phases, developed from the Palaeogene to the Holocene, have been recognized and discussed. Finally, stress field evolution is presented and compared with plate tectonic knowledge of the Western Mediterranean Basin. The usefulness of remotely-sensed data for this kind of work, with special reference to arid regions, is stressed in this study