Cataclastic Features on Europa

Europa, an icy moon around Jupiter, has a uniquely young surface history which implies ongoing resurfacing of its ice shell. Yet modeling of global stresses, the stresses that affect the moon as a whole, cannot reconcile the morphology of specific locations displaying regional deformation, such as Argadnel Regio. Development of a plate tectonic paradigm on Europa has served to constrain many of these unexplained tectonic morphologies. In regions where lateral motions in the ice shell have been hypothesized, rotational features imply a cataclastic process, similar to those found on Earth in fault zones. Cataclasis on Earth is a brittle process that involves microfracturing of the original rock, then the sliding and rolling of these fractured pieces, which leads to further mechanical breakdown. This study proposes to analyze and quantify the rotation of several “blocks” in Argadnel Regio and south of Agenor Linea (see Figure 1). The presence of rotational blocks in both regions suggests multiple areas are experiencing lateral shearing in the ice shell and that there is larger scale tectonic deformation on Europa than may have been previously appreciated. By developing a timeline for these deformation events this study aims to reveal the respective and possibly concurrent tectonic history of these regions, serving to quantify a plate tectonic paradigm for Europa.