something similar
I found this image (look towards the bottom):
http://barsoom.msss.com/moc_gallery/r03_r09/full_jpg_non_map/R08/R0802357.jpg
http://barsoom.msss.com/moc_gallery/r03_r09/images/R08/R0802357.html
recently. It's very similar to the one you are pointing out, though it's east of Meridiani. Since my theory is Meridiani is a former pole that's an interesting connection.
http://www.martianspiders.com/old/object9.jpg.htm
