300,000-Year-Old Hearth Found (1 of 2) (IMAGE) Weizmann Institute of Science Caption Upper left: This is an infrared spectrum of the grey sediments, right, showing that the dominant material is calcite, the mineral of which the wood ash is composed. Lower left: This is a photograph of the cave during excavation; arrow pointing to the hearth. Upper right: This is a micro-morphological image of the grey sediment showing dark grey particles and patches corresponding to the remains of wood ash. Lower right: This is a scan of a micro-morphological, thin section showing the layered burnt bones (yellow, brown and black fragments), intermixed with grey sediments. Credit Weizmann Institute of Science Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.