Chronology of compressional deformation on Mars: evidence for a single and global origin

Abstract

The chronology of compressional deformation on Mars is determined using chrono-stratigraphic relations and crater counting in order to provide new evidences for the origin of this deformation. Chronological relations between compressional tectonic features with different directions establish that a single deformation phase occurred in each studied region. On other hand, the intersections between tectonic features and craters permit to compare the relative age of the deformation in different regions. The results demonstrate that there may be a long lapse of time between the accumulation of Hesperian volcanic plains and the compressional deformation in each region. The possible age deduced for the compressional deformation on both Hesperian ridged plains and Noachian primitive terrains is Late Hesperian. A single and global phase may explain the compressional deformation because it is restricted to a single epoch. A global contraction of the planet may explain many properties of compressional tectonism on Mars according to the thermal evolution of the planets. Such process does not exclude secondary sources of stress like Tharsis bulge that would control the geometry of structures at regional scales.