Horizontal Procession Figures

Hi Researchers:

I came across these stones that in the creek where I am doing my research, which as far as I can tell is all specimens of human prehistory.  The creek is very gentle, spring fed, and not far from it's origin.  I found these stones together (they are about 4-6 inches tall as I remember).



I have no reason to think they are there for any other reason than they were manufactured put there...in prehistory, just like that.  The only thing that seems to wash out of the creek are fines and small pebbles.  Everything else appears more or less exactly where the project was dropped.  

The horizontal layout reminds me of some writing I found at Bear Church Rock, VA (very nice hike for research), a similar horizontal procession (boot for perspective).



Just wondering if anyone has any ideas about figures on these rocks.  I usually like to hold them to understand them, but I didn't want to mess with the ones in the creek for fear they would become unlocked and fall over. I wonder if there's some way to increase the contrast on the writing stone as well.