Thank you naturegirl,
there is a small pile of these, they were found a few miles west of downtown chicago, I have looked at these a few times through the years but never thought they were old.
Native americans smashed up clam shells and other material and mixed it with the clay for strength. The pices of shell can be seen if you look close enough. kind of looks like bread crumbs...
Definitely look old. I thought I could make out a little bit of shell in one piece but not sure. They would sometimes use sand for temper, but it wasn't the best method. They would grind up pieces of broken pots and throw that in too. I'm not familiar with the cultures of your area, but you should be able to do a little research and nail the origin down, especially since the pieces have designs. Sounds like a cool spot to check out!
Yup !! That there is primitive pottery. It seems to be relatively recent (last 200-1000 years) ,but I don't know the flavors of that neck of the woods. It could be older. The sideways pic appeared to have some shell tempering, but it looks more like bone or sand. Usually shell tempering is so obvious , you can easily see it. The crushed bone tempering is common with a salt and pepper look. Also crushed pottery was used as well. Keep your eyes on that wash , you may get enough shards of the same pot to reunite some of them. Thanks for showing. Lone Star