Pitted cones and domes on Mars: Observations in Acidalia Planitia and Cydonia Mensae using MOC, THEMIS, and TES data

Abstract

[1] Domes and cones with summit pits located in Acidalia Planitia and Cydonia Mensae were studied using MOC and THEMIS images and a TES-derived thermal inertia map. North of 40.5°N latitude, the features have a dome-like morphology, and south of that latitude, the morphology is more cone-like. Layering is apparent in the summit craters of fresher looking southern cones, and asymmetric aprons were observed in some instances. Some of the northern domes also display layering in their summit craters, but asymmetric aprons were not observed. The northern domes can also display multiple summit pits or no summit pits at all and can occur in association with higher-albedo ''pancake'' features. The northern domes are higher in albedo but have apparent thermal inertias that are lower than the surrounding plains. The apparent thermal inertia values of the southern cones range from values comparable to the surrounding plains to slightly lower. From the TES thermal inertia map, we infer that the thermal inertia values of the pitted cones are between those of basaltic fine dust and sand, while those of the surrounding plains are closer to that of basaltic sand. While a unique interpretation of the origin of the pitted cones is not possible with the available data, we do not find compelling evidence to suggest an origin related to either basaltic volcanism or ground-ice. Instead, an origin for these features through some combination of mud volcanism and evaporite deposition around geysers and/or springs is most consistent with the observations.

The stratigraphy and history of Mars' northern lowlands through mineralogy of impact craters: A comprehensive survey

“…The VBF has been suggested to have resulted from either volatile expulsion from the compaction of a fluid-laden sedimentary unit [Salvatore and Christensen, 2014b], local periglacial processes acting on outflow channel sediments and other older plain materials [Tanaka et al, 2003], sublimation residues , or ocean sediments [Parker et al, 1989[Parker et al, , 1993Baker et al, 1991]. On the surface of the Vastitas Borealis Formation many geomorphic features that could be related to aqueous activity have been identified, including polygonal troughs for ice/volatile-related processes [McGill and Hills., 1992;Hiesinger and Head, 2000;Yoshikawa, 2003;Mangold et al, 2004] and conical and domical features hypothesized to be mud volcanoes or springs [Farrand et al, 2005;Oehler and Allen, 2010]. Any hydrated/hydroxylated mineral associated with the unit may help to distinguish the different formation mechanisms for the Vastitas Borealis Formation.…”

“…) [Frey et al, 1979;Lucchitta et al, 1986;Farrand et al, 2005;Oehler and Allen, 2012]. The surface of the northern lowlands is covered by geologic units dated from the Early Hesperian to the Amazonian and has been mapped in great detail [Tanaka et al, 2005[Tanaka et al, , 2014.…”

Distribution, morphology, and morphometry of circular mounds in the elongated basin of northern Terra Sirenum, Mars

“…Proposed terrestrial analog features include impact craters, scoria cones, rootless cones, tuff cones/rings, pingos, and mud volcanoes (e.g., Farrand et al 2005;Meresse et al 2008;Burr et al 2009;de Pablo and Komatsu 2009;Oehler and Allen 2010;Brož et al 2015).…”

Garmada

“…Geyser activityrelated evaporite deposits are proposed as possible origin for some of the pitted cones/domes on Mars (Farrand et al 2005): ▶ mesoscale positive relief landforms, Mars. Io: Volcanic plumes of SO 2 are observed, reaching several hundreds of kilometer in vacuum.…”