Ancient sediment deposits dating back 1.5m years discovered in East Cork

Ancient sediment deposits, dating back 1.5m years, were discovered during the construction of EirGrid’s celtic interconnector project in East Cork.

At a recent webinar hosted by EirGrid, archaeologist Dan Noonan and underwater archaeology expert Michael Walsh revealed insights into Ireland’s ancient past.

One of the most significant discoveries made during the investigations was the identification of ancient sediment deposits, some of which were estimated to be more than 1.5m years old.

Mr Walsh outlined the significant deposits found.

“Samples recovered offshore from Claycastle Beach in Youghal were found to predate radiocarbon dating techniques (more than 50,000 years), so further samples were recovered for optically-stimulated luminescence dating, but the samples were found also to predate this technique (more than 1.5m years),” Mr Walsh said. 

“These findings offer a rare opportunity to better understand environmental conditions from a period far earlier than can typically be studied through conventional archaeological dating techniques.

“EirGrid’s extensive programme of investigations, licensed by the National Monuments Service, supported broader archaeological and geological research enhancing our understanding.

“This work has contributed valuable information that extends beyond the needs of the project itself,” he added.

Analysis of the deposits ultimately led researchers to conclude that the material was too old to have been associated with human occupation in the area.

Mr Noonan outlined archaeological works undertaken on land along the cable route, with the highest concentration of possible features found outside Killeagh.

Finds included fragments of 9th to 10th century clay tuyere from the Killeagh pavement scheme.

A tuyere is a tube or nozzle injected into a furnace or hearth during smelting or forging.

“From excavated features, a large number of fragments related to metal working were identified at Ballyedekin,” said Mr Noonan, adding that the fragments may be post-medieval.

The webinar was informed that soil samples are now being analysed, along with selected charcoal samples for radiocarbon dating.

“The radiocarbon dates, combined with information from the artefacts uncovered during excavation, will provide valuable insights into the function of these features and how the sites were used over time,” Mr Noonan said.