An eolith (from Greek "eos", dawn, and "lithos", stone) is a chipped flint nodule. Eoliths were once thought to have been artifacts, the earliest stone tools, but are now believed to be naturally produced by geological processes such as glaciation. Although the debate continued for about three decades, more and more evidence was discovered that suggested a purely natural origin for eoliths. This, together with the discovery of genuine early Lower Pleistocene Oldowan tools in East Africa, made support for the artifact theory difficult to sustain.