On the reliability of archaeomagnetic dating in Iberia: two case studies from Portugal and Zamora

Book chapter

Osete, M.L., Campuzano, S.A., Molina-Cardin, A., Palencia, A., Carmona, A., McIntosh, G. and Larrazabal, J. 2018. On the reliability of archaeomagnetic dating in Iberia: two case studies from Portugal and Zamora. in: Archaeology in the river Duero valley Cambridge Scholars Publishing. pp. 309-339
AuthorsOsete, M.L., Campuzano, S.A., Molina-Cardin, A., Palencia, A., Carmona, A., McIntosh, G. and Larrazabal, J.
Abstract

Archaeomagnetic investigations have been carried out on 22 combustion structures from Portugal and Spain, along the Duero River Valley at the archaeological sites of Crestelos and Olival Poço da Barca (NE Portugal) and at El Castillón (NW Spain). The age of most of the investigated structures at Portuguese sites ranges from the 3rd century BC up to Roman times according to archaeological information. At El Castillón the investigated kilns are considered to cover the 5th – 7th centuries AD. Stepwise thermal and alternating field demagnetization isolated a single, stable, characteristic remanence component with very well defined directions. Mean site directions were well grouped in most sites. Only the two most poorly preserved structures showed a relatively high directional dispersion. Classical Thellier paleointensity experiments were conducted on pilot specimens. Successful results were obtained in specimens from el Castillón and from Olival Poço da Barca. In contrast, alterations occurred during thermal treatment at Crestelos kilns and hearths.

Archaeomagnetic dating was conducted in all sites by using six reference Palaeosecular Variation (PSV) curves provided by local studies (from Iberia and France) and by regional (SCHA.DIF.3k) and global models (ARCH3k.1 and SHA.DIF.14k). The best PSV master curves for dating purposes on the investigated structures are the French curve for the old structures (older than 200 AD) and the regional SCHA.DIF.3k model for the younger structures. The new archaeomagnetic dating results suggest that the Crestelos site was active since 265±87 BC up to 252±138 AD, with a mean occupation period between 198 BC-43 AD. There could have been a previous occupation of the site but it could not be precisely dated. Distributions of the directions from Crestelos describe a PSV trend consistent with the French curve, suggesting that the archaeomagnetic dating tool could be improved in the near future by dating selected structures by independent methods. Archaeomagnetic dating at El Castillón site provide two phases of occupation of the site, at 441±12 AD and 488±53 AD, consistent with recent radiocarbon ages from the site. The effect of TRM anisotropy on directions has been evaluated, with the results highlighting the necessity for TRM anisotropy corrections if accurate dating is to be obtained.

KeywordsArchaeomagnetism; Archaeomagnetic dating; Geomagnetism; Palaeosecular variation; Iron Age
Page range309-339
Year2018
Book titleArchaeology in the river Duero valley
Book authorsSastre Blanco, J.C. and Rodriguez Monterrubio, O.
PublisherCambridge Scholars Publishing
Output statusPublished
File
License
All rights reserved
File Access Level
Controlled
ISBN97815275-3075
Publication process dates
Deposited26 Jun 2020
Permalink -

https://repository.canterbury.ac.uk/item/8vwq9/on-the-reliability-of-archaeomagnetic-dating-in-iberia-two-case-studies-from-portugal-and-zamora

  • 138
    total views
  • 0
    total downloads
  • 0
    views this month
  • 0
    downloads this month

Export as

Related outputs

La ocupación durante la Segunda Edad del Hierro del povoado de Crestelos (Meirinhos, Mogadouro, Portugal). Estructuras de combustión y reocupación del foso como zona productiva
José Carlos Sastre Blanco, David Sánchez Nicolás, Israel Espí Pérez, Alberto Molina Cardín, Saioa A. Campuzano, Alicia Palencia Ortas, Gregg McIntosh and María Luisa Osete 2022. La ocupación durante la Segunda Edad del Hierro del povoado de Crestelos (Meirinhos, Mogadouro, Portugal). Estructuras de combustión y reocupación del foso como zona productiva. Complutum. 33 (1), pp. 161-179. https://doi.org/10.5209/cmpl.80890
Further progress in the study of epsilon iron oxide in archaeological baked clays
Lopez-Sanchez, J, Palencia-Ortas, A, Del Campo, A, McIntosh, G., Kovacheva, M, Martin-Hernandez, F, Carmona, N, Rodriguez de la Fuente, O, Marin, P, Molina-Cardin, A and Osete, ML 2020. Further progress in the study of epsilon iron oxide in archaeological baked clays. Physics of the Earth and Planetary Interiors. 307, p. 106554. https://doi.org//10.1016/j.pepi.2020.106554
Updated Iberian archeomagnetic catalogue: new full vector paleosecular variation curve for the last three millennia
Molina-Cardin, A., Campuzano, S., Osete, M., Rivero-Montero, M., Pavon-Carrasco, F., Palencia-Ortas, A., Martin-Hernandez, F., Gomez-Paccard, M., Chauvin, A., Guerrero-Suarez, S., Perez-Fuentes, J., McIntosh, G., Catanzariti, G., Sastre Blanco, J., Larrazabal, J., Fernandez Martinez, V., Alvarez Sanchis, J., Rodriguez-Hernandez, J., Martin Viso, I. and Garcia i Rubert, D. 2018. Updated Iberian archeomagnetic catalogue: new full vector paleosecular variation curve for the last three millennia. Geochemistry, Geophysics, Geosystems. https://doi.org/10.1029/2018GC007781
New approaches to engineering higher education: case studies
Nortcliffe, A., McIntosh, G. and Hernandez, E. 2019. New approaches to engineering higher education: case studies.
New archaeomagnetic directions from Portugal and evolution of the geomagnetic field in Iberia from Late Bronze Age to Roman Times
Palencia-Ortas, A., Osete, M., Campuzano, S., McIntosh, G., Larrazabal, J., Sastre, J. and Rodriguez-Aranda, J. 2017. New archaeomagnetic directions from Portugal and evolution of the geomagnetic field in Iberia from Late Bronze Age to Roman Times. Physics of the Earth and Planetary Interiors. 270, pp. 183-194. https://doi.org/10.1016/j.pepi.2017.07.004
Epsilon iron oxide: origin of the high coercivity stable low Curie temperature magnetic phase found in heated archeological materials
Lopez-Sanchez, J., McIntosh, G., Osete, M., del Campo, A., Villalain, J., Perez, L., Kovacheva, M. and Rodriguez de la Fuente, O. 2017. Epsilon iron oxide: origin of the high coercivity stable low Curie temperature magnetic phase found in heated archeological materials. Geochemistry, Geophysics, Geosystems. 18, pp. 2646-2656. https://doi.org/10.1002/2017GC006929
End of the Kiaman Superchron in the Permian of SW England: Magnetostratigraphy of the Aylesbeare Mudstone and Exeter groups
Hounslow, M., McIntosh, G., Edwards, R., Laming, D. and Karloukovski, V. 2017. End of the Kiaman Superchron in the Permian of SW England: Magnetostratigraphy of the Aylesbeare Mudstone and Exeter groups. Journal of the Geological Society. 174 (1), pp. 56-74. https://doi.org/10.1144/jgs2015-141
A comparison of radiocarbon and archaeomagnetic dating from an archaeological site in Spain
Catanzariti, G., McIntosh, G., Osete, M., Nakamura, T., Rakowski, A., Ramirez Gonzalez, I. and Lanos, P. 2007. A comparison of radiocarbon and archaeomagnetic dating from an archaeological site in Spain. Radiocarbon. 49 (2), pp. 543-550.
Variation of rock magnetic parameters and paleointensities over a single holocene lava flow
Bohnel, H., Morales, J., Caballero, C., Alva, L., McIntosh, G., Gonzalez, S. and Sherwood, G. 1997. Variation of rock magnetic parameters and paleointensities over a single holocene lava flow. Journal of Geomagnetism and Geoelectricity. 49 (4), pp. 523-542.
A detailed record of normal-reversed-polarity transition obtained from a thick loess sequence at Jiuzhoutai, near Lanzhou, China
McIntosh, G., Rolph, T., Shaw, J. and Dagley, P. 1996. A detailed record of normal-reversed-polarity transition obtained from a thick loess sequence at Jiuzhoutai, near Lanzhou, China. Geophysical Journal International. 127 (3), pp. 651-664. https://doi.org/10.1111/j.1365-246X.1996.tb04045.x
Using time- and temperature-dependent Preisach models to investigate the limitations of modelling isothermal remanent magnetization acquisition curves with cumulative log Gaussian functions
Heslop, D., McIntosh, G. and Dekkers, M. 2004. Using time- and temperature-dependent Preisach models to investigate the limitations of modelling isothermal remanent magnetization acquisition curves with cumulative log Gaussian functions. Geophysical Journal International. 157 (1), pp. 55-63. https://doi.org/10.1111/j.1365-246X.2004.02155.x
A catalogue of Spanish archaeomagnetic data
Gomez-Paccard, M., Catanzariti, G., Ruiz-Martinez, V., McIntosh, G., Nunez, J., Osete, M., Chauvin, A., Lanos, P., Bernal-Casasola, D. and Thiriot, J. 2006. A catalogue of Spanish archaeomagnetic data. Geophysical Journal International. 166 (3), pp. 1125-1143. https://doi.org/10.1111/j.1365-246X.2006.03020.x
A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
Palencia-Ortas, A., Ruiz-Martinez, V., Villalain, J., Osete, M., Vegas, R., Touil, A., Hafid, A., McIntosh, G., van Hinsbergen, D. and Torsvik, T. 2011. A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes). Geophysical Journal International. 185 (3), pp. 1220-1234. https://doi.org/10.1111/j.1365-246X.2011.05017.x
New archaeomagnetic data recovered from the study of Roman and Visigothic remains from central Spain (3rd–7th centuries)
Catanzariti, G., Gomez-Paccard, M., McIntosh, G., Pavon-Carrasco, F., Chauvin, A. and Osete, M. 2012. New archaeomagnetic data recovered from the study of Roman and Visigothic remains from central Spain (3rd–7th centuries). Geophysical Journal International. 188 (3), pp. 979-993. https://doi.org/10.1111/j.1365-246X.2011.05315.x
Archaeomagnetic and rock magnetic study of six kilns from North Africa (Tunisia and Morocco)
Gomez-Paccard, M., McIntosh, G., Chauvin, A., Beamud, E., Pavon-Carrasco, F. and Thiriot, J. 2012. Archaeomagnetic and rock magnetic study of six kilns from North Africa (Tunisia and Morocco). Geophysical Journal International. 189 (1), pp. 169-186. https://doi.org/10.1111/j.1365-246X.2011.05335.x
Partitioning of magnetic particles in PM10, PM2.5 and PM1 aerosols in the urban atmosphere of Barcelona (Spain)
Aranzazu Revuelta, M., McIntosh, G., Pey, J., Perez, N., Querol, X. and Alastuey, A. 2014. Partitioning of magnetic particles in PM10, PM2.5 and PM1 aerosols in the urban atmosphere of Barcelona (Spain). Environmental Pollution. 188, pp. 109-117. https://doi.org/10.1016/j.envpol.2014.01.025
Recent developments in archeomagnetism: the story of the Earth's past magnetic field
Pavon-Carrasco, F., Osete, M., Campuzano, S., McIntosh, G. and Martin-Hernandez, F. 2015. Recent developments in archeomagnetism: the story of the Earth's past magnetic field. in: Eppelbaum, L. (ed.) New Developments in Paleomagnetism Research New York Nova Science Publishers. pp. 99-158