Tectonic-structural systems of Mars: Is it possible to use them to reconstruct its thermal evolution?

Abstract

This work tries to establish the possible relationship among cortical stresses evidenced by faults mapped in the surface and thermal evolution on Mars. To achieve it, we made an initial classification of the tectonic-structural systems that appear in surface, which were detected by diverse missions from orbit. This classification was based on the association of the tectonic-structural features with specific geologic features, which allows to divide them in four groups: I) Grabens and normal faults parallel and radially associated to the Tharsis volcanic bulge. II) Tectonic systems associated to the volcanoes that crown the Tharsis bulge, to the volcanic mons of Elysium and the surroundings of the Isidis, Argyre and Hellas impact basins. III) Wrinkle ridges that extend for almost the entire planet. IV) A series of secondary ridges associated to the crustal dichotomy. Later we suggest a classification based on the surface extension and on the possible geologic processes that could have originated the different tectonic structures. This last classification allows to associate stresses to specific processes and it contemplates three groups of deformations: local, regional and global deformations. Finally the possible causes of the stresses are suggested, which include: global stresses due to expansion or thermal contraction, regional or local stresses due to thermal anomalies in the mantle and to lithospheric loads, stresses due to impacts, among others. This allowed to suggest a possible thermal evolution that outlines an initial heating for accretion, followed by an abrupt cooling in a very short period of time and a later secular cooling, which remains in the present time.