Bosporus Planum

Scaled Image

Image Credit: NASA/JPL/ASU

About this image

This THEMIS image is of Bosporus Planum, located in a region of smooth plains that appear to have formed from lava flows. A crater, ~7 km in diameter, on the left edge of the image has produced an ejecta blanket that can be seen radiating from the crater. Lobes of ejecta such as those seen close to the crater rim are not formed at most typical craters and may indicate that there was a ice component in the subsurface material when the impact occurred. A linear depression trending from the northwest to southeast along the top of the image is about 1 to 2 km wide. This may be a tectonic feature, known as a graben, that forms when a region is under stresses that are pulling it apart. There are numerous small bright dunes or ripples along the margins of the floor of this linear feature that have formed perpendicular to the sides of the graben. This pattern of ripples suggests that the wind was blowing down the graben canyon. Similar small bright dunes can be faintly seen on top of the crater ejecta along ridges (most apparent directly to the east of the crater) and along the southern margin of the interior deposits in the crater. Bright wind streaks are also apparent in this area to the west (right) of several large craters. These streaks likely formed when very small particle size materials (like dust) is deposited on the surface and then protected from removal by the wind shadow produced by the crater's rim. Shorter dark streaks, possible deposits of dark sand, have formed to the east side of the smaller craters. These streaks on opposite sides of craters may indicate that there have been different wind patterns in the area, blowing in opposite directions. Subtle ridges near the south end of the image hint that there may have been other graben that have been nearly filled in. Many of the craters in this image have a subdued, buried appearance and may have been partially filled by lava flows or mantled by dust. A short geologic history of the area in this image can be created using the basic principles of geology, such as the principle of superposition (deposits that lie on top of other materials are younger). The linear depression must have formed after the deposition of the lava plains since it is a feature that would not have been otherwise preserved. Ejecta from the large crater has been deposited inside and over the edges of the linear depression, thus the crater must have formed after the linear depression. Finally, the bright dunes and dust streaks formed last because they have been deposited on top of all of these different features.

Please see the THEMIS Data Citation Note for details on crediting THEMIS images. 


Image ID: 
V01014003 (View data in Mars Image Explorer)
2002-03-07 17:35
Thu, 2002-04-18
1024 pixels (17 km)
3648 pixels (62 km)
0.017225 km/pixel
0.01735 km/pixel


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