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Oudemans Crater Central Uplift
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Oudemans Crater Central Uplift

February 1, 2007

This HiRISE image covers a portion of the central uplift of the 120-km diameter Oudemans crater.

Oudemans is located at the western end of Valles Marineris and just south of the great canyon system by the Noctis Labyrinthus. Images from the Mars Orbital Camera (MOC) were the first to reveal that this large impact crater exposed layered rock in its central uplift feature.

Such beautifully preserved layered rocks, although rare, are no surprise to planetary scientists. First, layered rocks exposed in the central uplifts are common in terrestrial impact structures. Secondly, there is abundant layering exposed in the nearby Valles Marineris canyon system — a gash that exposes layering down to 7 km beneath the mean surface. This suggests that layered materials exist to great depths in the subsurface, which is supported by the Oudemans central uplift observation.

Based on estimates of the depth of excavation for a crater the size of Oudemans, these layers originated from just as deep as those exposed in Valles Marineris and possibly deeper. A comparison of the layers in Valles Marineris and in the Oudemans central uplift may prove that they are similar rock types that share the same mode of origin. The fact that these layers are so well intact gives planetary scientists specific clues regarding the subsurface and history of the general area.

In addition, three other craters, Martin (21.2°S, 290.7°E), Mazamba (27.3°S, 290.2°E) and a yet unnamed crater (28.4°S, 305°E) also possess finely layered materials in their central uplift features and lie within the circum-Tharsis region. The preservation of the layering and geographical occurrence of these four craters suggests that they could be ash layers deposited from numerous episodes from the Tharsis volcanoes. Voluminous volcanic episodes could have produced large volumes of layered rock that could have been rapidly buried and protected from cratering.

Observation Geometry

Image PSP_001602_1700 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 29-Nov-2006. The complete image is centered at -9.9 degrees latitude, 268.2 degrees East longitude. The range to the target site was 255.8 km (159.9 miles). At this distance the image scale is 25.6 cm/pixel (with x binning) so objects ~77 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel and north is up. The image was taken at a local Mars time of 03:34 PM and the scene is illuminated from the west with a solar incidence angle of 59 degrees, thus the sun was about 31 degrees above the horizon. At a solar longitude of 142.6 degrees, the season on Mars is Northern Summer.



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