Dug as Metroon Porch Pit A and Pit C (layers II and III). ... 7th-6th c. B.C ... Dug as Metroon Porch Pit A and Pit C (layers II and III). ... Three layers, homogeneous in context, composed of dug bedrock fill, separated by distinct layers of poros working chips. In the lowest layer the dug bedrock was mixed with viscous red earth.