The ‘Genetic’ Analysis of Iberian Dolmens: A Test of the Idea in the Central Pyrenees

Abstract

In a previous paper on the topic (hereafter Paper 1 ),' the authors presented an extended statistical analysis of several groups of megalithic tombs in the Iberian Peninsula and neighbouring regions. In recent years, orientation studies and its statistical approach have received considerable attention in archaeology as a source of information that may shed light on a number of issues related to landscape and territory ownership by past cultures.2 The megalithic tombs, including dolmens, tholoi or allees couvertes, are no exception.Paper 1 presented a 'genetic' approach to the data,3 where the dendrogram, along with the Principal Components Analysis, clearly demonstrated that there was a link between the geographic location of the clusters of megalithic tombs and their respective orientation. The 27 neighbouring clusters of dolmens in the Iberian Peninsula tend to share orientation characteristics (see Figure 1). This result was true regardless of the type of dolmen and the epoch of construction, a fact which recalled a persistence of orientation custom and a necessary communication between neighbouring regions especially along river valleys or perhaps across mountain ranges such as the Pyrenees.In Paper 1, we also suggested a way of testing our hypotheses further, by checking whether there could have been a connection across the central Pyrenees, linking the dolmens of Navarre in the west to Catalonia in the east. This research note presents such a test for the hitherto unmeasured dolmens of the Pyrenees region of the province of Huesca where two dozen monuments had been reported.4 The dolmens in the area (see Figure 2) are of standard type and small dimensions, the body of the monument being enclosed in a tumulus or cairn of pebbles that have been preserved in several instances. These megalithic tombs have been dated to the third millennium b.c. and are thought to be the burial places of a community of shepherds moving across the Pyrenees and using the local grasslands during the hotter periods of the year. Of the nearly 30 monuments reported, about one-third were in a deplorable state of preservation and measurements were impossible. Another half-dozen could not be measured because they were in mountainous areas and so inaccessible.Table 1 presents the data of the 15 dolmens (plus one) obtained in two campaigns in the summers of 2010 and 201 1 .6This represents some three-quarters of the measurable structures and so is representative. Figure 3 shows the orientation diagram and the declination histogram of the data. High mountain peaks occupied wide areas of the horizon, and so it was crucial to take into account the angular heights and local topography. The value of this is shown in the declination histogram, where lunisolar orientations are dominant (-90% of the sample) despite the original dispersion of the azimuths as shown in the orientation diagram. This demonstrates the great superiority of in situ fieldwork over office software support tools in archaeoastronomical studies.The new dendrogram obtained after the inclusion of the data of the dolmens of the province of Huesca (HSCA) is to be seen in Figure 1 . Our new set of data is located in the dendrogram within a cluster where groups of nearby regions such as north-central Spain (NORT, including the megalithic tombs of neighbouring Navarre) and Catalonia (BRNA, GRNA and PIRI) are included. The dolmens of Corsica and Sardinia are also found in this cluster but this is more probably a cultural convergence than a real relationship. …