Analog Sites for Mars Missions II (2013) 4001.pdf THE TUNNEL VALLEY ANALOG OF THE INNER CHANNELS OF KASEI VALLES, MARS: KEY SITES IN THE MARS CHANNEL/TROUGH DEBATE. John D. Arfstrom, 3820 Losco Rd, #625, Jacksonville, Fl 32257, www.JohnArfstrom.com 904.200.2619. Introduction: The two inner channels of Kasei Valles share several characteristics with tunnel valleys (Figure, right mosaic), which are only formed under ice sheets and glaciers [1]. Elevation data also supports the interpretation of the inner channels as tunnel valleys, which supports a glacial interpretation of Kasei Valles, and, as such, they are keystone landforms in the glacial and flood hypotheses debate [2]. As part of the broader perspective (Figure, left pair), it appears that the head of the main trough or channel (Kasei Vallis Canyon) of Kasei Valles contains the remnant of a valley glacier [3]. The region of the main trough shows geomorphology consistent with both ice sheets and valley glaciations, and may indicate a change of glacial erosion from areal to slope only. This may reflect a winding down of glacial activity over time as related to Mars climate history. However, the remnant may be of a more recent cold-based glaciation. Another noteworthy feature in the area adjacent to the inner channels is a boundary between widespread ice mantled surfaces and less ice mantled surfaces straddling the inner channels. Ice mantling is also apparently present on the surrounding plains, which show groves consistent with glacially generated areal scour. It is probable that the ice mantle boundaries visible in the images below reflect a recent phase of orbital cycle driven surface ice mobilization not related to the period of the formation of the valley and the possible tunnel valleys. In a hypothetical mission scenario (refer to Figure), a rover could land on the scoured plains near the head of the main trough to evaluate the erosion as glacial or fluvial, and sample the possible ice mantles. The rover could then descend into the main trough to determine the composition of the filling material and likewise take samples of the possible glacier remnant. Following these investigations, the rover could continue down the main trough toward the inner channels, sampling icy remnants along the way, where the possible tunnels valleys could be scrutinized. References: [1] Benn B.I. and Evans J.A. (1998) Glaciers & Glaciation. Arnold Pub., p.332. [2] Arfstrom, J.D. (2013) LPSC Abstract, 44, 1001. [3] Arfstrom, J.D. (2013) LPSC Abstract, 44, 1002. Figure, left pair: (See “West Kasei Poster” at Scribd.com for higher resolution) (left) The head of main trough of Kasei Valles. CTXP180078911987XN18N074W. (right) Western Kasei Valles, Themis IR. Figure, right mosaic: (upper left) MOLA topography (100m) and THEMIS Day IR (middle): Downvalley inner channel. P180079702014XI21N072W, CTX: NASA/JPL/Un. of AZ. (middle left): Upvalley inner channel. G170247032009XN20N072W, CTX. (middle right): Digital elevation model, Vejle Tunnel Valley, Denmark..