Excavation at GMB identified sockets for an alignment of 18 stones .The waste material from their destruction could have been re-used in nearby passage graves e.g. Table des Marchands .(capstone and two orthostaas in that case ) .L'Helgouac'h reckons that the destruction of GMB was contemperaneous with the construction of TdM . Among the re-used were capstone at Mane Rutual , passage orthosats at TdM and Gavrinis , all carved .Other uncarved bits were found Kercado , Mane Lud and Petit Mont 3 .