He said: “We’ve found some quite significant archaeology. We’ve started to find structures that come away from the main gallery grave and we also have artefacts.
“So far the results have been quite spectacular.”
The Delancey Park structure is Guernsey’s only gallery grave, while there are two to be found in Jersey and more along the Atlantic coast of northern Europe.
Gallery graves belong to the late Neolithic period and are therefore more recently built than the more prevalent ‘passage’ graves, such as Les Fouillages and Dehus in the Vale.
Dr Nash explained: “The earlier constructions feature passages leading to an inner space, often with partitioned areas that may denote ‘engendering’ – the separate burial of males and females.