[S-EM18] Paleomagnetism and rock magnetism applied to solving geological and geophysical problems

[SEM18-P07] PRELIMINARY ARCHAEOMAGNETIC STUDY IN THE ARCHAEOLOGICAL SITE OF GRAKLIANI (REPUBLIC OF GEORGIA)

*Manuel Calvo-Rathert^1,5、Natalia Garcia-Redondo¹、Angel Carrancho²、Avto Gogichaishvili³、Vakhtang Licheli⁴ (1.Departamento de Fisica, EPS, Universidad de Burgos, Burgos, Spain 、2.Departamento de Historia, Geografía y Comunicación, Universidad de Burgos, Burgos, Spain.、3.Servicio Arqueomagnetico Nacional – Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Morelia, Mexico、4.Institute of Archaeology, Ivane Javakhishvili Tbilisi State University, Tbilisi, Georgia.、5.Hawaii Institute of Geophysics and Planetology, University of Hawaii at Manoa, Honolulu, Hawaii, United States)

キーワード：archaeomagnetism, archaeointensity, magnetic properties , anisotropy of thermoremanence, geochronology

We present a preliminary archaeomagnetic study carried out in the archaeological site of Grakliani (Republic of Georgia). Samples were taken during two different samplings (2018 and 2019) from nine combustion structures (ovens and possibly altars) and from different pottery fragments with a good age control. The age of all these samples varies between the 12^th century BC and the 1^st century BC, a broad period with scarce reliable archaeomagnetic data in the region.

We have performed an archeomagnetic and archaeointensity study on these samples at the paleomagnetic laboratory of the University of Burgos (Spain) and at the paleomagnetic laboratory Fort Hoofddijk in Utrecht University (The Netherlands). We carried out directional studies including both thermal demagnetization and stepwise alternating field as well as rock magnetic analyses, consisting in the measurement of IRM acquisition curves, hysteresis loops, backfield curves and high temperature thermomagnetic curves. Archaeointensity determinations were carried out with the Thellier-IZZI and Thellier – Coe protocols. They included additional experiments for anisotropy correction of the archaeointensity results.

So far, we have obtained a mean direction for each combustion structure and archaeointensity results for five combustion structures and five pottery fragments of different ages in the studied time range, which provide new full vector and intensity data of the Earth’s magnetic field variations in the Caucasus. Additional archaeointensity determinations in two other combustion structures are still in progress.