Deep-seated gravitational slope deformation scaling on Mars and Earth: same fate for different initial conditions and structural evolutions

Abstract

Abstract. Some of the most spectacular instances of deep-seated gravitational slope deformation (DSGSD) are found on Mars in the Valles Marineris region. They provide an excellent opportunity to study DSGSD phenomenology using a scaling approach. The topography of selected DSGSD scarps in Valles Marineris and in the Tatra Mountains is investigated after their likely similar postglacial origin is established. The deformed Martian ridges are larger than the deformed terrestrial ridges by 1 to 2 orders of magnitude with, however, a similar height-to-width ratio of ∼0.24. The measured horizontal spreading perpendicular to the ridges is proportionally 1.8 to 2.6 times larger for the Valles Marineris ridges than the Tatra Mountains and vertically 2.9 to 5.1 times larger, suggesting that starting from two different initial conditions, with steeper slopes in Valles Marineris, the final ridge geometry is now similar. Because DSGSD is expected to now be inactive in both regions, their comparison suggests that whatever the initial ridge morphology, DSGSD proceeds until a mature profile is attained. Fault displacements are therefore much larger on Mars. The large offsets imply reactivation of the DSGSD fault scarps in Valles Marineris, whereas single seismic events would be enough to generate DSGSD fault scarps in the Tatra Mountains. The required longer activity of the Martian faults may be correlated with a long succession of climate cycles generated by the unstable Martian obliquity.

Large-Scale and Deep-Seated Gravitational Slope Deformations on Mars: A Review

“…The preliminary morphological analyses carried out by some authors in the studies just described, were integrated and detailed in a subsequent work, which to date represents the latest study on DSGSDs on Mars. Kromuszczyńska et al [66] summarized the previous studies on morphological and dimensional characteristics of Martian large-scale slope deformation. Three DSGSDs of Valles Marineris were analyzed, located in Coprates Montes, along the ridge separating Melas and Candor Chasmata and the ridge located between Candor and Ophir Chasmata.…”

“…Often these morphological elements represent the gravitational re-activation of pre-existing tectonic structures [17,25]. On Mars, these types of phenomena show very similar morphological characteristics, although at least one order of magnitude larger due to the greater sizes of the slopes [64][65][66]. The typology of morphological elements found in the DSGSDs on Mars is comparable with those of the large-scale phenomena on Earth, as no peculiar elements have been found.…”

“…In generally, there are notable differences in morphological characteristics according to the geological settings to which the DSGSDs belong: (i) in Valles Marineris the deformational processes are mainly characterized by double-ridges, crestal graben, and uphill-facing scarps [59][60][61][64][65][66], while the other morphological elements and especially the bulging are rarely observable due to the thick detrital covers [60,66]; (ii) in the other sectors, the deformations are mainly characterized by trenches, faults, and bulging [68,70,72]. This differentiation seems to be both due to the genetic characteristics of DSGSDs and the geological-structural setting of the relief.…”

“…The DSGSDs in Valles Marineris are among the most spectacular of Mars, both for their considerable size and for the specific geomorphological characteristics. Along the chasmata flanks, the gravity-induced deformations appear as single-sided phenomena, mainly characterized by scarp and uphill-facing scarp systems [60,66]. In correspondence of the internal ridges, on the other hands, the large-scale gravitational deformations appear as double-sided phenomena, mainly characterized by double-ridges and crestal graben due to uphill-facing scarp systems and sagging of crest lines [12,60,66].…”

Surface Geomorphological Features of Deep-Seated Gravitational Slope Deformations: A Look to the Role of Lithostructure (N Apennines, Italy)

“…In the last few decades, deep-seated gravitational slope deformations (DSGSDs) have been established as one of the common geomorphological features of the world's mountain landscapes [1,2]. Since the first studies on these landforms [3][4][5][6], their presence has now been reported for many mountain chains, with numerous examples from across continents [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] and even from other planets [24][25][26]. In these decades, the interest towards the origin and the evolution of these landforms has attracted an increasingly wide amount of studies.…”