| Summary: | International audience We investigate the spectral and microwave properties of the raised rims of five liquid-filled Sharp Edged Depressions (SEDs) [e.g. 1;2;3] in Titan's North pole using both Cassini Visual and Infrared Mapping Spectrometer (VIMS) and RADAR data. The raised rims under investigation have been detected by RADAR stereogrammetry; they are a few hundreds of meters in height, a few kilometers wide, and in some cases, only partially surround the liquid-filled basin. Dedicated methods have been developed to extract their infrared spectra from a high-resolution VIMS cube [4;5] and their 2.2-cm emissivity from RADAR radiometry observations [6;7]. Comparison of the evaluated properties from the SEDs' terrains to that of other Titan regions of interest from all around the globe provide insights into the formation mechanisms of the elevated ramparts around Titan's SEDs. In particular, the emissivity of the considered raised rims is very close to that of the labyrinthic terrains and of the bottom of empty lakes. This suggests that the composition of the raised rims is most likely dominated by organics (rather than water ice). This is supported by the VIMS analyses that show spectral responses close to that of tholin-like materials and is consistent with of the hypothesis of a karst case-hardening post-deflation remnant hypothesis
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