Gradiometry survey and magnetic anomaly testing of Castros de Neixón, Galicia, Spain

Abstract

During the summer of 2011, a geophysical survey with subsequent magnetic anomaly testing was conducted in Northwest Iberia, in the province of Galicia, Spain, the most extensive evaluation of its kind to be performed on a Castro Culture hill fort with distinct Bronze and Iron Age occupations. The investigation focused on determining the spatial extent, occupation, and use of the multicomponent Bronze and Iron Age hill fort site(s) of Castros de Neixón.A Geoscan Research FM36 Fluxgate Gradiometer was used successfully to measure and identify magnetic anomalies interpreted as potential archaeological features within the occupation areas.Over 400 monopole and dipole magnetic anomalies were detected, many of which have been interpreted as representing pits, ditches, palisades, hearths and a possible corral. A parallel defensive ditch with zig-zag entrance was located north of the occupation at Castro de Neixón Grande. Subsurface testing of a promising monopole anomaly revealed a large storage pit with artifacts dating to the Castro period. New research since the 1990s has opened up traditional discussions linking the characteristic architecture of defensive walls and round structures (after which the Castro Culture was named) to a warrior-elite society, to more complex interpretations related to the intensification of agriculture and corresponding increase in sedentism. These new interpretations integrate domestic and agricultural features into Castro subsistence practices, including storage pits. Our results support these interpretations, revealing the extent to which storage pits are a dominant feature type at Castros de Neixón. Future research and subsurface excavations directed at understanding under-investigated features located via geophysical survey techniques at sites like Castros de Neixón may clarify questions surrounding Castro Culture social organization.