AbstractFaults and fractures may emplace fresh material onto Europa's surface, originating from shallow reservoirs within the ice shell or directly from the subsurface ocean. Ménec Fossae is a region of particular interest as it displays the interaction of several geological features, including bands, double ridges, chaotic terrains, and fossae, within a relatively small area. These features might affect the emplacement of buried material and subsequent exposure of fresh volatiles, prime targets for the upcoming JUICE and Europa Clipper missions in order to assess Europa's astrobiological potential. Previous studies have already revealed that a deep central trough is present at Ménec Fossae, flanked by several subparallel minor troughs and by a few asymmetrical scarps with lobate planforms. The presence of such features has motivated this study, given its potential to provide clear indications on the tectonic regime involved. Through detailed geomorphological‐structural mapping using Galileo Solid State Imager data and terrain analysis on Digital Terrain Models, we could develop a novel hypothesis on the formation mechanisms that might have been involved in the study area. We propose that Ménec Fossae has been shaped by transtensional (strike‐slip with an extensional component) tectonic activity, as indicated by the orientation and relationship of the tectonic features present. Likely, such transtensional tectonism occurred above or associated with shallow subsurface water, consistent with the overall morphology and topography of the study area and the presence of chaotic terrains and double ridges. These results strengthen the case for widely distributed shallow water reservoirs within Europa's ice shell.
Plain Language Summary: Tectonic cracks, which can originate from shallow water bodies within the icy crust or directly from the subsurface ocean, may emplace fresh material onto Europa's surface. This kind of material is a prime target for upcoming space missions to assess Europa's habitability. We investigated the area of Ménec Fossae, which is characterized by many different geological features and structures within a relatively small area and can therefore provide clues on the mechanisms that shaped it. Our analyses were based on imaging and new topographic data, we developed a new hypothesis involving a combination of different tectonic styles as the driving processes for the formation of this area. This kind of tectonic activity could be related to a liquid water pocket located at a shallow depth within Europa's icy crust, which might explain the concurrent presence of some particular geological features in the area. These findings strengthen the case for the wide distribution of shallow water pockets distributed within the icy crust, which could allow future space missions to more easily assess Europa's habitability.
Key Points:
Detailed geomorphological‐structural analysis of Ménec Fossae has been conducted, using imaging and newly processed topographic data
Ménec Fossae has been shaped by transtensional tectonic activity, potentially related to the emplacement of a shallow water reservoir
The hypothesis that shallow water reservoirs are widely distributed within Europa's ice shell is strengthened
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