Investigating the archaeointensity determination success of prehistoric ceramics through a multidisciplinary approach: new and re-evaluated data from Greek collections

Autor: Elina Aidona, K.G. Efthimiadis, Georgios S. Polymeris, Evdokia Tema, C. Carvallo, Ch. Rathossi, Miriam Gómez-Paccard, Despina Kondopoulou
Přispěvatelé: Institute for Aegean Prehistory (US), Ministerio de Economía y Competitividad (España), School of Geology [Thessaloniki], Aristotle University of Thessaloniki, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Minéralogie et magnétisme de basses dimensionnalités [IMPMC] (IMPMC_MIMABADI), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Scienze della Terra [Torino], Università degli studi di Torino = University of Turin (UNITO), ALP, Alpine Laboratory of Paleomagnetism
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
instname
Geophysical Journal International
Geophysical Journal International, 2017, 210 (3), pp.1450-1471. ⟨10.1093/gji/ggx224⟩
ISSN: 0956-540X
1365-246X
Popis: The Balkan area provides an almost continuous record of the geomagnetic field variations during the last eight millennia but important data dispersion and chronological gaps are still observed. In order to improve this pattern, we oriented our research towards the study of Greek prehistoric ceramics and pottery collections. We present here new archaeointensity and mineralogical results from pottery and ceramics collected in two Bronze Age sites in Northern Greece, corresponding to the middle third and middle second millennium BC. Thermal demagnetization experiments, thermomagnetic curves, thermal demagnetization measurements of three axes composite isothermal magnetization and first-order reversal curves (FORC) diagrams were performed in order to define the main magnetic carriers and select the most promising samples for archaeointensity determination. The results suggest that the majority of the studied materials are dominated by a mixture of superparamagnetic and stable single domain grains, with very little magnetic interactions. In almost all samples the main magnetic carrier observed is a low coercivity mineral, most probably magnetite and/or Ti-magnetite. Classical Thellier experiments, including both the thermoremanent magnetization anisotropy and cooling rate corrections were performed on the selected samples. Two new archaeointensities were obtained and compared with previous data available for Greece and neighbouring countries and with global geomagnetic field models results. In order to investigate the causes of the high rate of failure observed in our archaeointensity experiments, we re-examined the results obtained from the study of four collections already published by better characterizing the magnetic and mineralogical properties of the studied fragments. Specific hysteresis curves performed at different layers of ceramic fragments reveal an important degree of inhomogeneity. Mineralogical analysis of selected samples from the totality of six Greek prehistoric sites studied, including new X-ray powder diffraction analysis and a detailed description of the different geological contexts, is provided. The results suggest that the sherds were all fired in medium-high temperatures (mostly between 500° and 800 °C). The nature of the baked clay paste in response to the local geology appears to account for a part of the variability in magnetic properties. We suggest that X-ray powder diffraction analyses and thorough examination of the geological environment in combination with a satisfactory knowledge of the corresponding excavations history might provide an additional tool to appropriately select pottery fragments before performing future archaeointensity experiments.
The INSTAP Center has substantially contributed to the funding of this research during the years 2012–2014. MGP acknowledges the Ram´on y Cajal Program and the CGL2015–63888-R research project of the Spanish Ministry of Economy and Competitiveness.
Databáze: OpenAIRE
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