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, within a relatively small area, the interaction of several geological features such as bands, double ridges, chaotic terrains, and fossae. 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 already revealed that a deep central trough is present at Ménec Fossae, flanked by several subparallel minor troughs and by 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 on 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 a major extensional component) tectonic activity, as indicated by the orientation and relationship of the tectonic features present. The shear heating related to such a tectonic setting possibly led to the formation of a shallow water reservoir, that in turn could have generated the observed chaotic terrains, double ridges, and fossae. 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).…”

“…Galileo 's SSI data used in this manuscript can be accessed from the PDS Cartography and Imaging Science Node (Thaller, 2000), while the SSI photogrammetrically corrected base map mosaics can be accessed from the USGS Astrogeology website (Bland & Lynn, 2021). The Digital Terrain Model (Figure 2) and data of the structural map (Figure 3) produced are available on the Freie Universität Berlin Repository—Refubium (Matteoni & Neesemann, 2023).…”

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

“…Galileo's SSI data used in this manuscript can be accessed from the PDS Cartography and Imaging Science Node (Thaller, 2000), while the SSI photogrammetrically corrected base map mosaics can be accessed from the USGS Astrogeology website (Bland & Lynn, 2021). The Digital Terrain Model (Figure 3) and data from the geomorphological-structural map (Figure 4) produced are available on TRR 170-DB (Matteoni, 2022).…”