All articles tagged with #concretions
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.
The Klerksdorp Spheres, found in South Africa, have been the subject of conspiracy theories involving aliens and ancient civilizations due to their perfectly spherical shape and seam-like lines. However, geologist Bruce Cairncross offered a rational explanation for the spheres, stating that they are concretions formed by precipitation from an aqueous solution and consist of minerals crystallized in the host rock. The lines across the spheres are caused by imprints from the host rock, which was built up in layers over time. The mystery of why the sphere supposedly spun "on its own" was explained by the curator of the Klerksdorp Museum, stating that it is quite natural for it to rotate a bit due to earth tremors caused by mining activities.