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V-P. Kostama, M. Aittola, J. Raitala, T. Öhman (University of Oulu)
This study was done from the two quadrangles of the Hellas impact basin, the MC-27 (Noachis) and MC-28 (Hellas). The Hellas region is very versatile area and offers good possibilities to research several geological structures and events as well as interactions between them: Hellas impact basin and its central parts and boundaries, highland patera formations, and several large outflow channels. The comparison of all highland paterae around the Hellas basin and studying their relations with the outflow channels may provide evidence of volcanic activity-permafrost interaction as well as information on the old post-impact volcanism and catastrophic outflow processes. Eolian activity is also very interesting within the region, based on the fact that Hellas is thought to represent a major source region for regional dust storms on Mars.
The region provides possible evidence for glacial activity on Mars. It has been proposed that the interior of the Hellas basin held ice-covered lakes early in Mars history. There are morphologic, stratigraphic, and topographic evidence implying that first water-laid, then later ice-rich, sediments dominated the geology of the Hellas interior. On Mars, there are also a variety of features that have been attributed to the presence of local ground ice and permafrost. These features include lobate debris aprons and rampart craters, which are abundant in the Hellas region. We also have several larger craters with interaction by post-impact fluvial activity. This may be indication for lacustrine deposits of some craters with smooth basin floors.
Several proposed target sites include also parts of the Hellespontus Montes, which is supposed to represent the oldest material in the region, and the system of grabens, which is more or less parallel to Hellas rim. This system occurs at radial distances between 1900-2500 km to west and and north-west from the basin center.
The author(s) of this abstract have provided an email address for comments about the abstract: petri.kostama@oulu.fi