Khirbat en-Nahas (IMAGE) University of California - San Diego Caption Industrial copper slag mound excavated at Khirbat en-Nahas. The building and layers above it date to the mid-9th century BCE; slag deposits below the building date to the 10th century BCE. Credit Photo by Thomas Levy, UC San Diego. Usage Restrictions With credit. 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.