TERRESTRIAL GULLIES ON SVALBARD AS PLANETARY ANALOGS FOR MARS

Martian gullies resemble terrestrial gul-lies, which are formed by a combination of processes includ-ing mass wasting, overland flow and debris flows. The gullies on Mars show several morphologic features such as braided channels, multiple terraces, point bars and cutbanks, which indicate that fluvial processes were involved in their formation. However, it remains unclear whether fluvial processes or debris flows are dominating the formation of gullies on Mars. Debris flows are viscous slurry flows with water and fines as the interstitial fluid. The flowing mix-tures of fines, clastic debris and water has a relatively low water content (? 30 % water by weight). Stream flows and hyperconcentrated flows have a high water content and relatively low sediment supply (? 30 % water by weight). The morphologies of debris flows fans show typical fea-tures such as levees, lobes, snouts and debris plugs, which are not observed from purely fluvial processes. In this work we compare the morphology of terrestrial gully analogs from Svalbard with Martian gullies in order to constrain which formation process might be dominant on Mars, i.e. fluvial and/or debris flow processes.