My property was a coral reef at one point. There's too much to explain so here is a small example, not the only type of coral. There's other kinds, but primarily this. And it's inches below the grass. I understand it's not coral anymore.
I'm in Ohio, that's why I am asking. I noticed the coral last summer but with everything else I am finding the coral became common so I plowed through it every time. Doesn't matter where you dig, some form of coral is there. About a foot down is sandstone floor and lava rock. It's not slag, I work in a steel mill and see slag everyday. This is scoria I believe. Here's a chunk of the sandstone from the property, I broke it and brought it back to the house.
The big long stem is sea Lilly, left is horn and tab coral in bad shape. Top is brachiopods and small traces of ammonites, there's a lot going on in that one. And the right oval piece is one of the largest clam shell I've found
Based on your first post you already know your property was under water and you are digging up fossils. I apologize for not reading it more carefully. What do you want answered?
No problem at all. I am wondering how all of this is still here? According to the states geological website, a lot of the stuff I'm finding shouldn't be here. Examples: anthracite coal, colonial coral, volcanic rock. The propriety is out in the middle of nowhere, high elevation, 400-500 feet above average. You can see for miles up here. I dug a deep hole on the far opposite side of the property to compare and see what is down a few feet. I hit sand and what appears to be scoria. Also, to cover the foundry slag theory, that is not even a possibility with the location and history. I can safely rule that out
The clay surface has held the form of the coral, under that it has fossilized into rock, and then below that it is black and grey shale that is water and air tight, yellow clay/silt, and then sand. Not Florida Gulf side sand, more like larger grain Atlantic sand and this is buried in there. I'll post a photo. I dug a 3x3x3 hole and that's the layers.