Stratigraphy, Crater Size–Frequency Distribution, and Chronology of Selected Areas of Ganymede’s Light and Dark Terrains

Abstract

The stratigraphy of the largest natural satellite of our solar system, Ganymede, is investigated using available global mosaic (basemap) and high-resolution images. We are focusing on the reconstruction of the formation and tectonic evolution of selected areas of dark and light terrain units and investigate their morphological characteristics and relative ages at a local scale using high-resolution images from the sub-Jovian and anti-Jovian hemispheres. For this, geological maps and crater size–frequency distributions for each of the terrain units were prepared, and relative as well as absolute ages were derived by applying the currently available lunar-derived impact chronology model and the Jupiter-family comet chronology model. The relative ages obtained from the cross-cutting relationships of terrain units are not always consistent with the ages derived from the crater size–frequency distributions. Some regions are influenced by secondary and sesquinary craters and tectonic resurfacing activities. Independent of the applied model, the derived crater size–frequency distribution showed that the light terrain started to form soon after the completion of dark terrain formation.