
Ohio’s Backyard Orbs Reveal an Ancient Ocean Story
Columbus-area backyard rocks are spherical concretions—millions of years old, formed when minerals precipitated around organic material in Ohio’s Devonian seas about 360 million years ago; these concretions are found across Ohio in yards and parks (notably Shale Hollow Park) in sizes from centimeters to large, up to nine feet, with fossils inside being possible but rare, offering a window into ancient ocean chemistry.













