[X] My Assistant

[djellison]

http://www.unmannedspaceflight.com/doug_im...aving_larry.jpg (476kb)

Larry is the outcropping to the right - Methuselah is the layered rock on the left.

As an interesting point to judge distances - assuming zero slip the marks made by the hold-down-brackets on the wheel tread are 80cm apart - or about 2ft 7inches

Doug

[Tman]

It could be a deposit by a single event. And what we see now is only weathered by wind that forms such layer-like appearance. Anyway the composition seems to be aggregated.

[Guest_Edward Schmitz_*]

It could be a deposit by a single event. And what we see now is only weathered by wind that forms such layer-like appearance. Anyway the composition seems to be aggregated.

Without actual layers, there is no way that the wind can etch pseudo layers. There has to be hardness differences to allow uneven erosion to occur. If there are hardness differences that are aligned along parallel planes, then you have layers by definition.

[john_s]

Without actual layers, there is no way that the wind can etch pseudo layers.  There has to be hardness differences to allow uneven erosion to occur.  If there are hardness differences that are aligned along parallel planes, then you have layers by definition.

True, except that if you have a rock with random variations in hardness, e.g. a volcanic ash containing various-sized chunks of broken-up rock, and you then erode it by wind, you'll get aligned tails of protected soft material extending downwind behind the hard chunks, giving the impression of layering. I think this is at least part of what's happening at Methuselah, as in this area. There are probably real layers too, but I think the wind erosion helps make the layers look finer-scale than they really are, particularly as the wind happens to be roughly parallel to the bedding.