This would suggest the (seemingly) unlikely possibility that all of these layers had moved downslope the same amount regardless of where they are located. One argument against downslope motion is the observation that the uppermost rounded boundary of these layers typically occurs at approximately the same distance below the ridge crest. Alternatively, these unique features could be the result of the slow downslope motion of the surface layer, possibly enhanced by the presence of ground ice. The presence of water ice in these layers is a likely possibility to account for their preservation only on the colder surfaces. This observation suggests the layer once draped the entire knob and has since been removed from all but the north-facing slopes. In several locations, such as in the large knob directly south of the "Face," these deposits occur at several different heights on the hill. It has been suggested that these deposits were "pasted" on the slopes, with the distinct, rounded boundary on their upslope edges being the highest remaining point of this pasted-on layer. Many of the hills and ridges in this area also show unusual deposits of material that occur preferentially on the cold, north-facing slopes. Erosion has completely removed these layers in most places, leaving behind only the small isolated hills and knobs seen today. These ledges are made of more resistant layers of rock and are the last remnants of layers that once were continuous across this entire region. Many of these knobs, including the "Face," have several flat ledges partway up the hill slopes. The THEMIS image provides a broad perspective of the landscape in this region, showing numerous knobs and hills that have been eroded into a remarkable array of different shapes. Like the hills and knobs of Mars, however, Camelback Mountain was carved into its unusual shape by thousands of years of erosion. ![]() A similar-size hill in Phoenix, Arizona resembles a camel lying on the ground, and Phoenicians whimsically refer to it as Camelback Mountain. Since that time the Mars Orbiter Camera on the Mars Global Surveyor spacecraft has provided detailed views of this hill that clearly show that it is a normal geologic feature with slopes and ridges carved by eons of wind and downslope motion due to gravity. This 3-km long knob, located near 10° N, 40° W (320° E), was first imaged by the Viking spacecraft in the 1970's and was seen by some to resemble a face carved into the rocks of Mars. The so called "Face on Mars" can be seen slightly above center and to the right in this THEMIS visible image.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |