I've not come across this before! I wish my soil wasn't sitting under 5" of snow right now. I want to try this test! This is really interesting. I know they call this soil lakebottom silt because Lake Hitchcock covered this whole area 10,000 years ago. I know there's a permeable clay layer 4' down. I know the topsoil used to be 4' deep and is now around 2' or less. But I've never done a test like this one.
Snow has disappeared here luckily! Been warming up more and more every day here.
I wish you luck with your soil testing... sounds like you may have some issues. That's a lot of clay.
Not 4' of clay, just a permeable layer 4' down. LOL
lol- see what happens when I read off my cell phone and am NOT wearing glasses- got that comment ALL mixed up!