Experimental Petrology to Understand Europa's Crust

Abstract

The Jovian moon Europa is a prime target for astrobiology. A global subsurface water ocean and a geologically young surface provide evidence of an active planetary body with a potential deep habitable environment. Tectonism and cryomagmatism are both agents of resurfacing, with structures on the surface spatially related to reddish non‐icy materials that could represent crystallized volatile and salt‐rich fluids from the interior, possibly from the ocean or shallower aqueous bodies. Cryomagmatism could therefore be a mechanism for exposing the underlying liquid layers to the surface and could hold paramount importance for understanding the physical and chemical evolution of fluids during their ascent and emplacement and their connection with geological features at the surface. With these premises, we perform a set of laboratory experiments simulating the evolution of different fluids under the conditions in Europa's crust. These experiments allow us to constrain the physico‐chemical and textural changes experienced by the different fluids and solids that are potentially emplaced within the icy crust and determine how they are affected by such secondary processes as reheating, melting, and ultimate recrystallization (e.g., in response to the emplacement of a second diapir close to the first one or tidal reheating). Based on these experimental results, we explore the connection of cryomagmas and their evolution near the surface to geologic features present on Europa's surface, such as pits, uplifts/domes, and microchaos regions, as well as the link with explosive cryovolcanism responsible for putative plumes at Europa.