Main pit (image) University of Otago Share Print E-Mail Caption A closeup from a section of the main pit. The joining, closed pipi shells in the centre (right of the 550mm tape increment) were radiocarbon dated to the period 1430-1460 CE. Credit University of Otago Usage Restrictions None Share Print E-Mail 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.