Los factores litológicos como indicadores del paisaje en el megalitismo de la penillanura salmantina (centro-oeste de España)

Abstract

A lithological study of the passage graves of the Salamanca peneplain has been carried out, considering 15 monuments and about 130 megalithic blocks. The weights and dimensions of the megaliths have been estimated, as well as the nature of the rocks used for the construction of both chambers and corridors. Six rock types can be distinguished, with the following proportions: granite (38%), mylonite (21%), quartzite (16%), metapelite (13%), quartz (10%) and augen gneiss (2%). The provenance of the source material was analysed, and a minimum distance for the transport of each block is proposed. Using a statistical approach, a gap (bimodality) is inferred between close and distant intervals of minimum distance, which cannot be explained in terms of any practical purpose. Long-distance transport is more common for the megaliths of the chambers than those used for the corridors. In certain well-preserved passage graves, radial routes of transport appear to have been involved, allowing a possible spatial organization of the landscape to be inferred. In particular, a distinction between central monuments, showing varying types of rocks and also long-distance transport, with respect to peripheral ones, with the local transport of homogeneous megaliths, is established. The organized space probably covered an area of about 65 km2; at least for the megalithic group of Villarmayor, which shows a diversity of funerary monuments and settlements. This scenario of centrality is analysed with a view to gaining an understanding of the main components of the landscape, such as symbolism (rituals, sanctuaries�), social organization (pasturelands, agriculture, pottery�) and contrasted geological formations (granite, slate and large quartz dykes), all seeming to be mutually linked. A certain alignment of the funerary is inferred in relation to a route of transport that follows a big quartz dyke (�sierro�) and this likely enhanced the mobility of groups and the articulation between the different components of the landscape. Several significant centred monuments from Western Europe have been compared with the Villarmayor megalithic centre, resulting in a certain constancy of the long-distance transport of megaliths, with a range of 3-8 km.