This is a shot of the red clay found around the Roanoke area.  It’s an acidic soil that’s common around the southeastern United States; sciencey types call it a “ultisol.”  The rust color results from … actual rust, if I understand correctly.  It’s full of iron oxide.

I don’t think my camera phone does it justice — it’s actually redder than it appears below.  I have no doubt Roanoke natives hardly notice it, but it looks strange at first to a carpetbagger.