butte du Hu

The necropolis has three distinct sites: the Butte du Hu to the north; the second tumulus about 400 m further south; and a group of six passage graves (named A, B, C, D, E and F) to the south-east of the two tumuli. Mechanical test trenches confirmed that there are no structures between these three entities.

The eight monuments are very homogeneous in construction. All were built with slabs and thin plaquettes of limestone of two types, a hard, fine Bathonian limestone and a soft oolitic limestone, both from a large extraction quarry halfway between the two tumuli, where the two rocks occur in two superimposed beds. The arrangement of the monuments and the variety of their ground plans may correspond to a social hierarchy.

All the monuments are rounded in form. Their diameters range from 10 m (graves A1 and A2) to 20 m (the tumuli and graves B and D). They have a facing of large dry-stone slabs, and the internal structure of the cairns is more heterogeneous, a mixture of slabs and plaquettes. The chambers of the two tumuli and of the six graves are reached by a straight passage. That of the Butte du Hu is roofed with lintels and opens onto a circular chamber topped by a small vault of small stones.

The six passage graves originally formed a compact group extending from north to south, but the near-destruction of grave F gives the impression of two separate groups. When excavated, the graves survived to a height of only 0.30 to 0.40 m, but originally they must have risen to 5 m. All the chambers were roofed by corbelling. Grave A contains two burial chambers (A1, A2) that fit closely together and were probably built in a single operation. All the chambers have much the same floor area. Grave B is surrounded by a trench that may have served as a setting pit for orthostats or posts.

The floors are paved (Butte du Hu and the passage graves) but in different ways: medium-sized slabs (grave D) or paving of plaquettes (graves B and E).

The Butte du Hu was excavated in 1833 by F. Galeron over two days. M. Bellivet excavated the second tumulus in 1847. A new campaign of excavations begun in 1985 found the six passage graves, completely levelled by ploughing, a short distance from the two known tumuli.

In the Butte du Hu, Galeron found ten skeletons laid with their feet turned towards the centre of the chamber, and some fragments of pottery. Bellivet found eleven burials in the second tumulus. In the six passage graves the burials correspond to about forty individuals. The bodies were originally placed with their backs against the walls. Together with the bones found in the passage graves, the whole necropolis may have received about 70 burials, about 12 deposits per chamber on average. A genetic study of the twelve skeletons from grave C showed that these individuals had no maternal ancestry.