Integrated Analytical Techniques for the Study of Colouring Materials from Two Megalithic Barrows |
| |
| Authors: | C. Oliveira A. M. S. Bettencourt A. Araújo L. Gonçalves I. Kuźniarska‐Biernacka A. L. Costa |
| |
| Affiliation: | 1. REQUIMTE/LAQV, Polytechnic of Porto – School of Engineering (ISEP), Porto, Portugal;2. Department of Heritage Studies, University of Porto, Via Panoramica Edgar Cardoso, S/N, Porto, Portugal;3. Landscape, Heritage and Territory Laboratory (Lab2 PT), Department of History, University of Minho, Campus de Gualtar, Braga, Portugal;4. Earth Sciences Centre, University of Minho, Campus de Gualtar, Braga, Portugal;5. REQUIMTE/LAQV, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Porto, Portugal;6. Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leix?es, Avenida General Norton de Matos, S/N, Matosinhos, Portugal |
| |
| Abstract: | We have determined the composition of rock art pigments from two megalithic barrows located in the north of Portugal. The use of XRD, SEM–EDS and FT–IR spectroscopy confirmed the presence of hematite and kaolinite in the red pigments from the Eireira barrow, and kaolinite in the white pigment from the Leira das Mamas barrow. The organic composition of the pigments was studied by GC–MS, suggesting that the red sinuous lines and dots from the Eireira barrow were prepared with cooked or heated algae and/or aquatic plants, with egg as binder, while the white pigment from the Leira das Mamas barrow revealed a mixture of vegetable oils for kaolinite moulding, which could be stabilized by temporary exposure to high temperatures. The multi‐analytical approach used on this study of megalithic pigments allowed the recovery of important data about north‐western prehistoric communities, namely the way in which they exploited existing resources and their ability to transform them. |
| |
| Keywords: | megalithic barrows pigments colouring materials Gas Chromatography – Mass Spectrometry (GC– MS) chemical analysis |
|
|
