The dark areas in the picture above are the ditches filled with dark organic humus.  The light area in between is the yellowish, sandy sub-soil that is typical of this part of the terrace.  

Even though many of the crew’s notes describe this feature as a spiral, it is actually more accurate to describe this feature as a series of concentric circles. The title of this blog post, “The Spiral at Ranelius,” just seemed to have a better ring to it than “The Series of Concentric Circles at Ranelius.”  Aside from being an unusual, surface-visible feature, the nature of this circle remains unclear.  It should be noted that due to errors in word-of-mouth accounts over the years, the circular ditches at Ranelius has been referred to in recent literature as “a spiral mound”.  This is one of the problems that occur when reports are not written for excavations.