Ménec Fossae on Europa: A Strike‐Slip Tectonics Origin Above a Possible Shallow Water Reservoir

Abstract

Faults 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.

Evolution of Thrace Macula on Europa: Strike‐Slip Tectonic Control and Identification of the Youngest Terrains

“…An in‐depth analysis of the varying tectonic setting along the whole Libya Linea would be necessary to determine which of these two hypotheses should be favored, a goal that goes beyond the scope of the present work. It is, however, worth noting that local transtension has already been observed in other parts of Libya Linea (e.g., Matteoni et al., 2023).…”