Sedimentology and Hydrology of an Amazonian paleo-fluivo-lacustrine systems on Mars (Moa Valles)

Post contributed by Francesco Salese from IRSPS/Dipartimento INGEO, Università D’Annunzio, Pescara, Italy.

Mars, is one of the planetary bodies where water flowed and where it may transiently flow today under certain conditions. Many martian paleodrainage systems and well-preserved fluvial and lacustrine deposits have been recognized and studied in the last two decades (see further reading). Widespread dendritic valley networks and the presence of extensive fluvial features on ancient martian terrains suggest that a relatively “warm and wet” climate was prevalent early in the planet’s history (about 3.7 Ga). This is in stark contrast with the hyper-arid, extremely cold climate that is thought to have persisted from 3 Ga until the present (Amazonian Era). The subject of this post is Moa Valles [Salese et al., 2016], which is a 2 billion year old paleodrainage system (Figure 1) that is nearly 300 km long and is carved into ancient highland terrains of Tempe Terra in the northern hemisphere of Mars. Understanding the origin and evolution of this type of complex and interconnected paleo-fluvio-lacustrine system is critical for understanding the early martian climate.

Figure2

Figure 1: The upper panel shows the THEMIS-VIS daytime mosaic of Moa Vallis system.The lower panel is a line drawing showing the channel system in blue lines, red dotted lines represent wrinkle ridges, the drainage basin is delimited in grey, and fan-shaped and deltaic deposits in orange. The total mapped length of the channel as shown here is ~325 km, and the flow direction is towards the east.

The Moa Vallis paleofluvial system consists of a series of dam-breach paleolakes with associated fan-shaped sedimentary deposits. The paleolakes are interconnected and drain eastward into Liberta crater, where there is a complex and multilobate deltaic deposit with a well-developed channelized distributary pattern with evidence of avulsion on the delta plain (Figure 2).

Figure1

Figure 2 Colourised CTX digital elevation model (created from G07_020918_2154_XI and P02_001772_2154) draped on the visible image (6 m/px). The fan delta is indicated on the left with the trunk channel and the dam breach area on the right.

 

A breach area, consisting of three spillover channels, is present in the eastern part of the crater rim. These channels connect the Liberta crater to the eastward portion of the valley system, continuing towards the main trunk of Moa Valles which has a complex pattern of anabranching channels (Figure 3) stretching over 180 km.

Based on hydrological calculations of infilling and spillover discharges of the Liberta crater lake, the formation of the whole fluvial system is consistent with short to medium (<1000 year) timescales, conversely from comparison with terrestrial analogs, the length and morphology of the observed fluvial-lacustrine features suggest long-term periods of activity (Figure 4).  The relatively recent activity of the Moa Valles fluvio-lacustrine system was likely sustained by relatively short fluvial events (<100 years), thereby supporting the hypotheses that water-related erosion might have been active on Mars (at least locally) during the last 3 Ga, despite this epoch being commonly considered as having a cold and dry climate. The water source for the system could have been shallow ice melting triggered by impact.

Figura_15

Figure 3 Colourised CTX digital elevation model (stereo pairs G17_024821_2147_XI_34N055W, G16_024320_2148_XI_34N055W and G15_024254_2149_XI_34N054W, P16_007231_2143_XI_34N054W) draped over the images, showing multiple-thread channel system (38 km long) with very low stream gradient and a highly variable width among the individual channels. Channel width/depth ratios and sinuosities vary from very low to very high.

NFigura_25

Figure 4 CTX D05_029054_2166_XN_36N054W digital elevation model draped on HiRISE image (ESP_029054_2165 with 25 cm/px resolution) showing very well preserved example of possible meander cutoff in Moa Valles.

Further reading:

Ansan, V., et al. (2011), Stratigraphy, mineralogy, and origin of layered deposits inside Terby crater, Mars, Icarus, 211(1), 273–304, doi:10.1016/ J.Icarus.2010.09.011.

Baker, Victor R., et al. Fluvial geomorphology on Earth-like planetary surfaces: A review. Geomorphology 245 (2015): 149-182.

Carr, Michael H. The fluvial history of Mars.Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences 370.1966 (2012): 2193-2215.

Di Achille, G., and B. M. Hynek (2010), Ancient ocean on Mars supported by global distribution of deltas and valleys, Nat. Geosci., 3(7), 459–463.

DiBiase, R. A., A. B. Limaye, J. S. Scheingross, W. W. Fischer, and M. P. Lamb (2013), Deltaic deposits at Aeolis Dorsa: Sedimentary evidence for a standing body of water on the northern plains of Mars, J. Geophys. Res. Planets, 118, 1285–1302, doi:10.1002/Jgre.20100.

Fischer, E., G. M. Martínez, H. M. Elliott, and N. O. Rennó (2014), Experimental evidence for the formation of liquid saline water on Mars, Geophys. Res. Lett., 41, 4456–4462, doi:10.1002/2014GL060302.

Goudge, T. A., K. L. Aureli, J. W. Head, C. I. Fassett, and J. F. Mustard (2015), Classification and analysis of candidate impact crater-hosted closed-basin lakes on Mars, Icarus, 260, 346–367.

Hauber, E., T. Platz, D. Reiss, L. Le Deit, M. G. Kleinhans, W. A. Marra, T. de Haas, and P. Carbonneau (2013), Asynchronous formation of Hesperian and Amazonian-aged deltas on Mars and implications for climate, J. Geophys. Res. Planets, 118, 1529–1544, doi:10.1002/jgre.20107.

Hecht, M. H. (2002), Metastability of liquid water on Mars, Icarus, 156(2), 373–386, doi:10.1006/Icar.2001.6794.

Hobley, D. E. J., A. D. Howard, and J. M. Moore (2014), Fresh shallow valleys in the Martian midlatitudes as features formed by meltwater flow beneath ice, J. Geophys. Res. Planets, 119, 128–153, doi:10.1002/2013JE004396.

Howard, A. D., and J. F. Moore (2011), Late Hesperian to early Amazonian midlatitude Martian valleys: Evidence from Newton and Gorgonum basins, J. Geophys. Res., 116, E05003, doi:10.1029/2010JE003782.

Irwin, R. P., R. A. Craddock, and A. D. Howard (2005), Interior channels in Martian valley networks: Discharge and runoff production, Geology, 33(6), 489–492, doi:10.1130/G21333.1.

Mangold, N. (2012), Fluvial landforms on fresh impact ejecta on Mars, Planet. Space Sci., 62(1), 69–85, doi:10.1016/J.Pss.2011.12.009.

Mangold, N., and V. Ansan (2006), Detailed study of an hydrological system of valleys, a delta and lakes in the Southwest Thaumasia region, Mars,
Icarus, 180(1), 75–87, doi:10.1016/J.Icarus.2005.08.017.

Ori, G. G., L. Marinangeli, and A. Baliva (2000), Terraces and Gilbert-type deltas in crater lakes in Ismenius Lacus and Memnonia (Mars), J. Geophys. Res., 105(E7), 17,629–17,641, doi:10.1029/1999JE001219.

Salese, F., G. Di Achille, A. Neesemann, G. G. Ori, and E. Hauber (2016), Hydrological and sedimentary analyses of well-preserved paleofluvial-paleolacustrine systems at Moa Valles, Mars, J. Geophys. Res. Planets, 121, 194–232, doi:10.1002/2015JE004891.

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1 Comment

  1. Haruki Chou

     /  April 3, 2016

    I would like the same article with bigger images.

    Reply

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