Karst Landforms in a Martian Evaporitic Dome

Abstract

UDC 911.2:551.435.8:523.43 Davide Baioni, Nadja Zupan Hajna & Forese Carlo Wezel: Karst landforms in a Martian Evaporitic Dome e Tithonium Chasma is the northern trench of the western troughs of Valles Marineris (Mars). In the eastern part of the canyon system a mountain displaying a dome shape morphology is located. According to OMEGA mineralogical data (OMEGA data orbit 531_3) and further studies the dome appears to consist of magnesium sulphate (kieserite), an evaporitic mineral also found on the Earth. Previous works highlighted the presence of karst-like landforms and morphologies that strongly resemble the evaporitic karst morphologies found on the Earth. rough the analysis of the new MRO HiRISE images we have investigated the Martian landform and the possible processes involved in their formation and shaping in great detail. e analysis carried out show that the landforms observed clearly indicate the presence of solutional processes that also acted in a selective way, highlighting that the Martian dome can be formed of di erent materials (minerals, grain-size, ect.) with di erent solutional properties. e results of our observation also suggest that on the dome liquid water must have existed in the past for enough time so that the solution features we investigated could be formed. Keywords: Mars, kieserite, dissolution, karst features. (Mars). V njegovem vzhodnem delu leži gora, ki kaže značilno kupolasto obliko dome. Mineraloški podatki pridobljeni z OMEGA spektrometrom (podatki OMEGA orbit 531_3) in nadaljnje študije kažejo, da doma sestoji iz magnezijevega sulfata (kizerit), evaporitnega minerala, ki ga najdemo tudi na Zemlji. Predhodne raziskave dome poudarjajo prisotnost krasu podobnih oblik in oblik, močno podobnim oblikam evaporitnega krasa na Zemlji. Z analizami novih posnetkov MRO HiRISE smo raziskovali izbrano Marsovo površino in predvideli možne procese, ki bi lahko imeli pomembno vlogo pri njenem nastanku in oblikovanju. Opravljene analize so potrdile, da opazovane oblike površja jasno nakazujejo prisotnost procesov raztapljanja. Iz oblik se da sklepati tudi na prisotnost selektivne korozije, ki pa tudi nakazuje, da doma sestoji iz različnih materialov (minerali, zrnavost, itd.), ki se drugače obnašajo pri raztapljanju. Rezultati naših opazovanj tudi nakazujejo, da je na domi nekoč morala obstajati tekoča voda in to dovolj časa, da so korozijske oblike lahko nastale. Izvleček

Possible evaporite karst in an interior layered deposit in Juventae Chasma, Mars

“…This process would be the same of what happens on ice-covered terrains on Earth. Hence, the melting of ice or snow would provide the water necessary for the dissolution and collapse processes, as already proposed for the karst landforms found in other regions of Mars, such as Sinus Meridiani (Baioni & Sgavetti, 2013;Flahaut et al, 2015), Tithonium Chasma (Baioni et al, 2009;Baioni & Wezel, 2010;Wezel & Baioni, 2010;Baioni, 2013), Coprates Chasma (Baioni et al, 2011), Hebes Casma (Grindrod & Balme, 2010;Jackson et al, 2011) and Tyrrhena Terra (Baioni & Tramontana, 2016), as well as in karst terrains of Canada, the United States, Russia and the high mountain regions of Europe.…”

“…4F). Additionally, they display strong morphological convergence with the evaporite dolines described in other regions of Mars, such as Tithonium Chasma (Baioni et al, 2009;Baioni & Wezel, 2010;Baioni 2013), Coprates Chasma (Baioni et al, 2011), Hebes Chasma (Grindrod & Balme, 2010;Jackson et al, 2011), Sinus Meridiani (Baioni & Sgavetti, 2013;Baioni et al, 2014;Flahaut et al, 2015), Iani Chaos (Baioni & Tramontana, 2015) and other regions (McKey & Nedell, 1998;Schaeffer, 1990;Spencer & Fanale, 1990).…”

“…Recent works based on new high-resolution images demonstrate the presence of karst landforms such as doline depressions in several Martian evaporite deposits (Baioni et al, 2009;Baioni & Wezel, 2010;Grindrod & Balme, 2010;Jackson et al, 2011;Flahaut et al, 2015), highlighting the usefulness of karst landforms as lithological, stratigraphic and paleoclimatic markers (Baioni & Sgavetti, 2013;Baioni & Tramontana, 2015).…”

Evaporite karst in three interior layered deposits in Iani Chaos, Mars

“…In recent years, the presence of soluble evaporite minerals on Mars -as evidenced by data from the OMEGA instrument (Bibring et al, 2006) on the Mars Express, the Mars Exploration Rovers, and the Compact Reconnaissance Imaging Spectrometer for Mars instrument (Murchie et al, 2007) on the Mars Reconnaissance Orbiter (MRO) -have supported the possible development of evaporite karst similar to that on Earth (Stafford and Boston, 2005) and the presence of karstic terrains with associated caves (Johnston et al, 2006). Recent works based on new highresolution images have demonstrated the presence of karst landforms and processes in Martian evaporite deposits (Baioni et al, 2009;Baioni and Wezel, 2010;Grindrod and Balme, 2010;Jackson et al, 2011;Wezel and Baioni, 2014) and have highlighted the usefulness of the karst landforms as lithological, stratigraphic (Baioni and Sgavetti, 2013), and paleoclimatic (Baioni et al, 2011;Baioni, 2013) markers.…”

Secondary minerals from salt caves in the Atacama Desert (Chile): a hyperarid and hypersaline environment with potential analogies to the Martian subsurface

“…Similarly in the Atacama desert caves, sulphates like blödite and leonite are the result of the concentration in these elements sourced by regional volcanic material interlayered with halite deposits. Given the evidence that some evaporitic terrains on Mars have been subject to karst or thermo-karst processes (Baioni et al, 2014;Baioni & Tramontana, 2016) probably resulting in solutional cavities (Boston, 2004;Baioni et al, 2009), the Atacama caves represent a promising analogue to secondary mineral formations and the potential of life in the Martian subsurface.…”