Valles Marineris

A short account of what we think we know

Valles Marineris (Figure 1) formed in a bedrock thought to be a succession of lava flows and pyroclastites (McEwen et al., 1999; Beyer et al., 2005), which in some areas overly crystalline rocks that may represent an older basement or intrusives. Crystalline rocks are well observed on some Coprates Chasma walls (Williams et al., 2003), along which dykes have also been locally identified at 3 sites (Flahaut et al., 2011). Chasma depositional and erosional history has been the topic of many post-Viking Valles Marineris studies. Most of them were hypothesized as soon as Mariner 9 obtained the first images of Valles Marineris in 1972 (Sharp et al., 1973).

Figure 1. ESA/DLR/HRSC digital elevation model of Valles Marineris (scale in meters) with location of the main chasmata and other troughs.

Chasma initiation

There is ample evidence that extensional tectonics has played a significant role in forming the southern chasmata, from observation that the troughs are parallel to narrow grabens observed on the plateau in which Valles Marineris formed and fault-population statistics (Schultz, 2000; Vallianatos et al., 2011) from internal chasma structural segmentation and from neotectonic morphologies (Peulvast et al., 2001). Most researchers indeed share the view that the chasmata are dominantly of tectonic origin (Masson, 1977, 1980; Frey, 1979; Schultz, 1991, 1995, 2000; Mège and Masson, 1996a, 1996b; Peulvast et al., 2001; Vallianatos et al., 2011; Andrews-Hanna et al., 2012; Tanaka et al., 2014). The structural similarities between Valles Marineris and rifts in the terrestrial sense, advocated in the Viking Orbiter times (Masson, 1977; Frey, 1979), remain interesting to investigate but need to be nuanced (Lucchitta et al., 1992; Mège et al., 2003; 2014; Hauber et al., 2010). The absence of horizontal offset of lava flow margins, which are abundant on the plateau surrounding Valles Marineris, is evidence of purely normal fault slip. Strike-slip parallel to the Valles Marineris chasmata has been advocated on the basis of hypothetical plate tectonics-based scenarios (Anguita et al., 2001, 2006; Yin et al., 2012a) but the presented observational evidence of geologic marker displacement (Yin et al., 2012b) is not supported by observations at higher resolution. Geomorphological considerations suggest that the northern, oval-shaped chasmata, although in the same extensional tectonic setting, have a partly different history than the southern chasmata (Schultz, 1998; Schultz and Lin, 2001), perhaps involving enigmatic "ancestral basins" (Schultz, 1998; Fueten et al., 2008, 2010) formed either by erosion, by vertical collapse into huge underlying tension fractures (Tanaka and Golombek, 1989; Jackson et al., 2011) or following vertical shears (Andrews-Hanna et al., 2012; Fueten et al., 2008).

There is very little evidence of tectonic deformation related to a far-field source or body forces generated by the Tharsis lithospheric load that would postdate the initial chasma formation stage. Most fault scarps and other deformation have been interpreted or reinterpreted as due to diagenesis (Okubo, 2009) and gravity or paraglacial tectonics (Okubo et al., 2008; Mège and Bourgeois, 2011; Gourronc et al., 2014; Okubo, 2010, 2014).

Further evolution

Further evolution. A long history of deposition and erosion took place, in which the unstable rotation axis of Mars (Laskar et al., 2004) probably played a key role, although accurate reconstruction of the rotation parameters cannot be computed for ages older than 10 Ma (Laskar et al., 2002). The sedimentary history mainly includes deposition of stratified deposits1 up to kilometres thick (Figure 2), the morphology of which denotes significant variations in erosional susceptibility, that probably correlates with variations in composition.

Nevertheless, they have been globally ascribed the name of Interior Layered Deposits (ILD). Near-infrared orbital spectra from MEx/OMEGA and MRO/CRISM indicate that these rocks include a proportion of sulfates (Gendrin et al., 2005; Mangold et al., 2008; Wendt et al., 2011) and ferric oxides (Le Deit et al., 2008; Wendt et al., 2011; Fergason et al., 2014). ILD fast degradation and retreat suggest that ice is a major component of ILDs (Grindrod and Warner, 2014), in agreement with the low viscosity of some of them, which have been interpreted as glaciers (Mège and Bourgeois, 2011; Gourronc et al., 2014) eroding mafic rocks and altering them to sulfates (Niles and Michalski, 2009; Cull et al., 2014). The ILD show internal deformation (Fueten et al., 2005, 2008, 2010, 2011, 2014) that is best interpreted as local effects (Okubo et al., 2008) such as gravity adjustments or sedimentary unconformities. Other minerals identified in Valles Marineris include clays (Weitz et al., 2015), hematite (Roach et al., 2010a) and hydrated minerals (Roach et al., 2010b).

Gravity tectonics has been a major component of wallrock modification, probably throughout the Valles Marineris history (Quantin et al., 2004), for instance by rock glaciers (Mège and Bourgeois, 2011; Brunetti et al., 2014), deep-seated gravitational slope deformation features (Mège and Bourgeois, 2011; Makowska et al., 2016), landslides -Quantin et al., 2004; Brunetti et al., 2014; Lucas et al., 2011;  Lajeunesse et al., 2006), and rolling boulders (Chojnacki et al., 2014). Fluvial erosion and lacustrine deposition have also been documented (Quantin et al., 2005).


Figure 2: Synthetic geologic cross-section of eastern Candor Chasma (Mège et al., 2016), showing the basement in brown and red, ILD in blue, and other deposits in green and yellow.

Valles Marineris origin

Quite early, simple elastic models of Tharsis formation (Banerdt et al., 1982, 1992; Sleep and Phillips, 1985) have generated discussions (Schultz and Zuber, 1994; Mège and Masson, 1996c) about the source of stress that could have generated extension in Valles Marineris, especially whether plume uplift stress or magmatic load stress provide the suitable stress trajectory patterns. These models were oversimplified, as elastic models cannot adequately describe crust or lithosphere rheology (Banerdt and Golobek, 1992), strain path (Schutlz and Zuber, 1994), relevant topography (Mège and Masson, 1996c), and eventually, the complexity of plume tectonics (Schultz and Zuber, 1994; Mège and Masson, 1996c). Later qualitative models of continental rifting above a mantle plume (Ernst et al., 2001; Mège et al., 2001) provide a reasonable and valuable framework for understanding the orientation and formation of Valles Marineris at the first order. Such a plume tectonics model (Mège and Masson, 1996b) predicts that chasma geometry follows the orientation of a huge mafic dyke swarm (Figures 3 and 4), similar to volcanic rifts on Earth (Mège and Masson, 1996b; Mège, 2001), and consistent with observational evidence that depressions parallel to the giant chasma may be related to magma withdrawal by fissure eruptions (Mège et al., 2003).

Figure 3: Geologic time scales of Mars and Earth in m.y., with simplified indication of events mentioned in this project (Mège and Massno, 1996b: Mège and Bourgeois, 2011; Gourronc et al., 2014; Tanaka et al., 2014). Martian time scale after Hartmann and Neukum (2001), Earth time scale after the International Commission on Stratigraphy.

Figure 4: The Tharsis plume tectonics model Mège and Masson, 1996b) predicts that Valles Marineris opened following the orientation of a dyke swarm centred on the Syria Planum magma centre, the inversion of which results in the displayed stress trajectories. Stress field analysis indicates a stress regime controlled by magmatic overpressure and a regional crustal stress source.

Cited works

Andrews-Hanna JC (2012) The formation of Valles Marineris: 1. Tectonic architecture and the relative roles of extension and subsidence. J. Geophys. Res. 117, doi:10.1029/2011JE003953.

Anguita F et al. (2001) Tharsis dome, Mars: new evidence for Noachian-Hesperian thick-skin and Amazonian thin-skin tectonics. J. Geophys. Res. 106, 7577-7589.

Anguita F et al. (2006) Evidences for a Noachian-Hesperian orogeny in Mars. Icarus 185, 331-357, doi:10.1016/j.icarus.2006.07.026.

Banerdt WB, Golombek MP (1992) Constraints on the structure and evolution of the Tharsis region on Mars. Planetary Geosciences, NASA SP-508, 4-6.

Banerdt WB et al. (1982) Thick shell tectonics on one-plate planets': Applications to Mars. J. Geophys. Res. 87, 9723-9733.

Banerdt WB et al. (1992) Stress and tectonics on Mars. In: Kieffer HH et al. (eds) Mars, Univ. Arizona Press, 249-297.

Beyer et al. (2005) Layering stratigraphy of eastern Coprates and northern Capri Chasmata, Mars. Icarus 179, 1-23, doi:10.1016/j.icarus.2005.06.014.

Brunetti MT et al. (2014) Analysis of a new geomorphological inventory of landslides in Valles Marineris, Mars. Earth Planet. Sci. Lett. 405, 156-168, doi:10.1016/j.epsl.2014.08.025.

Chojnacki M et al. (2014) Valles Marineris dune fields as compared with other martian populations: Diversity of dune compositions, morphologies, and thermophysical properties. Icarus 230, 96-142, doi:10.1016/j.icarus.2013.08.018.

Cull S et al. (2014) A new type of jarosite deposit on Mars: Evidence for past glaciation in Valles Marineris? Geology 42, 959-962, doi:10.1130/G36152.1.

Ernst RE, Grosfils EB, Mège D (2001) Giant Dyke Swarms on Earth, Venus and Mars. Ann. Rev. Earth Planet. Sci., 29, 489-534.

Fergason RL et al. (2014) Hematite-bearing materials surrounding Candor Mensa in Candor Chasma, Mars: implications for hematite origin and post-emplacement modification.  Icarus 237, 350-365, doi:10.1016/j.icarus.2014.04.038.

Flahaut J et al. (2011) Dikes of distinct composition intruded into Noachian‐aged crust exposed in the walls of Valles Marineris. Geophys. Res. Lett. 38, L15202, doi:10.1029/2011GL048109.

Frey H (1979) Martian canyons and East African rifts: structural comparisons and implications. Icarus 37, 142-155.

Fueten F et al. (2005) Structural attitudes of large scale layering in Valles Marineris, Mars, calculated from Mars Orbiter Laser Altimeter data and Mars Orbiter Camera imagery. Icarus 175, 68-77, doi:10.1016/j.icarus.2004.11.010.

Fueten F et al. (2008) Stratigraphy and structure of interior layered deposits in west Candor Chasma, Mars, from High Resolution Stereo Camera (HRSC) stereo imagery and derived elevations. J. Geophys. Res. 113, E10008, doi:10.1029/2007JE003053.

Fueten F et al. (2010) Structural analysis of interior layered deposits in Northern Coprates Chasma, Mars. Earth Planet. Sci. Lett. 291, 343-356, doi:10.1016/j.epsl.2009.11.004.

Fueten F et al. (2011) Interior layered deposits within a perched basin, southern Coprates Chasma, Mars: Evidence for their formation, alteration, and erosion. J. Geophys. Res. 116, E02003, doi:10.1029/2010JE003695.

Fueten F et al. (2014) Stratigraphy andmineralogy of CandorMensa,West Candor Chasma, Mars: Insights into the geologic history of Valles Marineris. J. Geophys. Res. Planets 119, 331-354, doi: 10.1002/2013JE004557.

Gendrin A et al. (2005) Sulfates in Martian Layered Terrains: The OMEGA/Mars Express View. Science 307, 1587-1591, doi:10.1126/science.1109087.

Gourronc M et al. (2014) One million cubic kilometers of fossil ice in Valles Marineris: relicts of a 3.5 Gy old glacial landsystem along the Martian equator. Geomorphology 204, 235-255, doi:10.1016/j.geomorph.2013.08.009.

Grindrod PM, Warner NH (2014) Erosion rate and previous extent of interior layered deposits on Mars revealed by obstructed landslides. Geology 42, 795-798, doi:10.1130/G35790.1.

Hauber et al. (2010) Martian rifts: Structural geology and geophysics. Earth Planet. Sci. Lett. 294, 393-410, doi:10.1016/j.epsl.2009.11.005.

Hartmann WK, Neukum G (2001) Cratering chronology and the evolution of Mars. Space Sci. Rev. 96, 165–194.

Jackson MPA et al. (2011) Modeling the collapse of Hebes Chasma, Valles Marineris, Mars. Geol. Soc. Am. Bull. 123, 1596-1627, doi: 10.1130/B30307.1.

Lajeunesse E et al. (2006) New insights on the runout of large landslides in the Valles-Marineris canyons, Mars. Geophys. Res. Lett. 33, L04403, doi:10.1029/2005GL025168.

Laskar J et al. (2002) Orbital forcing of the martian polar layered deposits. Nature 419, 375-377.

Laskar J et al. (2004) Long term evolution and chaotic diffusion of the insolation quantities of Mars. Icarus 170, 343-364, doi:10.1016/j.icarus.2004.04.005.

Le Deit L et al. (2008) Ferric oxides in East Candor Chasma, Valles Marineris (Mars) inferred from analysis of OMEGA/Mars Express data: identification and geological interpretation. J. Geophys. Res. 113, E07001, doi:10.1029/2007JE002950.

Lucas A et al. (2011) Influence of the scar geometry on landslide dynamics and deposits: Application to Martian landslides. J. Geophys. Res. 116, E10001, doi:10.1029/2011JE003803.

Lucchitta BK et al. (1992) The canyon system on Mars. In: Kieffer HH et al. (eds) Mars, Univ. Arizona Press, 453-492.

McEwen AS et al. (1999) Voluminous volcanism on early Mars revealed in Valles Marineris. Nature 397, 584-586.

Makowska M et al. (2016) Mechanical conditions and modes of paraglacial deep-seated gravitational spreading in Valles Marineris, Mars. Geomorphology 268, 246-252, doi:10.1016/j.geomorph.2016.06.011.

Mangold N et al. (2008) Spectral and geological study of the sulfate-rich region of West Candor Chasma, Mars. Icarus 194, 519-543, doi:10.1016/j.icarus.2007.10.021.

Masson P (1977) Structure Pattern Analysis of the Noctis Labyrinthus-Valles Marineris Regions of Mars. Icarus 30, 49-62.

Masson P (1980) Contribution to the structural interpretation of the Valles Marineris – Noctis Labyrinthus – Claritas Fossae regions of Mars. Moon Planets 22, 211-219.

Mège D (2001) Uniformitarian plume tectonics: the post-Archean Earth and Mars. In: Ernst RE, Buchan KL (eds), Mantle plumes: Their Identification through Time. Geol. Soc. Am. Spec. Pap. 352, 141-164.

Mège D, Bourgeois O (2011) Equatorial glaciations on Mars revealed by gravitational collapse of Valles Marineris wallslopes. Earth Planet. Sci. Lett. 310, 182-191.

Mège D, Masson P (1996a) Amounts of stretching in Valles Marineris. Planet. Space. Sci. 44, 749-782.

Mège D, Masson P (1996b) A plume tectonics model for the Tharsis province. Planet. Space Sci. 44, 1499-1546.

Mège D, Masson P (1996c) Stress models for Tharsis formation, Mars. Planet. Space Sci., 44, 12, 1471-1497.

Mège D et al. (2003) Volcanic rifting at Martian grabens. J. Geophys. Res., 108, doi:10.1029/2002JE001852.

Mège D et al. (2014) Origin of the observed deformation in Valles Marineris: an equatorial fossilised glacier system and no regional tectonics. MPSE 2014, Warsaw, Poland, ESA MPSE 2014, C37.pdf.

Mège D et al. (2016) The Highland Terrain Hopper (HOPTER): concept and examples of use of a new locomotion system for the exploration of low gravity Solar System bodies. Acta Astronautica 121, 200-220, doi:10.1016/j.actaastro.2015.12.042.

Niles PB, Michalski J (2009) Meridiani Planum sediments on Mars formed through weathering in massive ice deposits. Nature Geoscience 2, 215-220,, doi:10.1038/NGEO438.

Okubo CH (2009) Deformation band clusters on Mars and implications for subsurface fluid flow. Geol. Soc. Am. Bull. 121, 474-482, doi: 10.1130/B26421.1.

Okubo CH (2010) Structural geology of Amazonian-aged layered sedimentary deposits in southwest Candor Chasma, Mars. Icarus 207, 210-225, doi:10.1016/j.icarus.2009.11.012.

Okubo CH (2014) U.S. Geol. Survey, Scientific Investigations Map 3309.

Okubo CH et al. (2008) Relative age of interior layered deposits in southwest Candor Chasma based on high-resolution structural mapping. J. Geophys. Res. 113, E12002, doi:10.1029/2008JE003181.

Peulvast JP et al. (2001) Morphology, evolution and tectonics of Valles Marineris wallslopes (Mars). Geomorphology 37, 329–352.

Quantin C et al. (2004) Ages of Valles Marineris (Mars) landslides and implications for canyon history. Icarus 172, 555-572, doi:10.1016/j.icarus.2004.06.013.

Quantin C et al. (2005) Fluvial and lacustrine activity on layered deposits in Melas Chasma, Valles Marineris, Mars. J. Geophys. Res. 110, E12S19, doi:10.1029/2005JE002440.

Roach LH et al. (2010a) Diagenetic haematite and sulfate assemblages in Valles Marineris. Icarus 207, 659-674, doi:10.1016/j.icarus.2009.11.029.

Roach LH et al. (2010b) Hydrated mineral stratigraphy of Ius Chasma, Valles Marineris. Icarus 206, 253-268, doi:10.1016/j.icarus.2009.09.003.

Schultz RA (1991) Structural development of Coprates Chasma and Western Ophir Planum, Valles Marineris Rift, Mars. J. Geophys. Res. 96, 22,777-22,792.

Schultz RA (1995) Gradients in extension and strain at Valles Marineris, Mars. Planet. Space Sci. 43, 1561-1566.

Schultz RA (1998) Multiple-process origin of Valles Marineris basins and troughs, Mars. Planet. Space Sci. 46, 827-834.

Schultz RA (2000) Fault-population statistics at the Valles Marineris Extensional Province, Mars: implications for segment linkage, crustal strains, and its geodynamical development. Tectonophysics 316, 169–193.

Schultz RA, Lin J (2001) Three-dimensional normal faulting models of the Valles Marineris, Mars, and geodynamic implications. J. Geophys. Res. 106, 16,549-16,566.

Schultz RA, Zuber MT (1994) Observations, models, and mechanisms of failure of surface rocks surrounding planetary surface loads. J. Geophys. Res. 99, 14,691-14,702.

Sharp RP (1973) Mars: troughes terrain. J. Geophys. Res. 78, 4063–4072.

Sleep N, Phillips RJ (1985) Gravity and lithospheric stress on the terrestrial planets with reference to the Tharsis region of Mars. J. Geophys. Res. 90, 4469-4489.

Tanaka KL, Golombek MP (1989) Martian tension fractures and the formation of grabens and collapse features at Valles Marineris. Proc. 19th Lunar Planet. Sci. Conf., 383-396.

Tanaka KL et al. (2014) Geologic map of Mars. U.S. Geol. Survey Sci. Invest. Map 3292, Pamphlet, 43 p.

Vallianatos F, Sammonds P (2011) A non-extensive statistics of the fault-population at the Valles Marineris extensional province, Mars. Tectonophysics 509, 50-54, doi:10.1016/j.tecto.2011.06.001.

Weitz CM et al. (2015) Mixtures of clays and sulfates within deposits in western Melas Chasma, Mars. Icarus 251, 291-314, doi:10.1016/j.icarus.2014.04.009.

Williams JP et al. (2003) Layering in the wall rock of Valles Marineris: intrusive and extrusive magmatism. Geophys. Res. Lett. 30, 1623, oi:10.1029/2003GL017662.

Yin A (2012a) An episodic slab-rollback model for the origin of the Tharsis rise on Mars: Implications for initiation of local plate subduction and fi nal unifi cation of a kinematically linked global plate-tectonic network on Earth. Lithosphere 4, 6, 553-593, doi: 10.1130/L195.1.

Yin A (2012b) Structural analysis of the Valles Marineris fault zone: Possible evidence for large-scale strike-slip faulting on Mars. Lithosphere 4, 4, 286-330, doi: 10.1130/L192.1.