A few layers of rock contain several concretions. We called these dinosaur eggs when we were younger, not knowing exactly what they were. We have come to find that these are simply hard, compact masses of matter. These settle within the muds and sands that make the local rocks. SomeRead More →

This brachiopod is beautifully centered in what is likely a concretion circle. The specimen was found in the high-hill shale. This layer contains a shale that I call mud stone. It comes out in larger pieces than thinner shale. The rock still splits rather easily, and it contains many concretions.Read More →