34 Paleomagnetism, Rock Magnetism, Environmental Magnetism, Instrumentation, Archaeomagnetism, Planetary Magnetism, and Petrofabrics

Thursday, 17 March 2022
8:00 AM - 12:00 PM
CBC-A 110

FIRST ARCHAEOMAGNETIC RESULTS FROM THE PROTOHISTORIC GRAKLIANI HILL SITE (GEORGIA, CAUCASUS)

Paper number: 34-3
Program: Theme Sessions
Time: 8:40 AM – 9:00 AM

Authors

Abstract

In this study we present archeomagnetic and archaeointensity results obtained on burnt archaeological material from the Grakliani archaeological site in the Republic of Georgia. Based on stratigraphic and archaeological information, all studied samples have been chronologically framed between the 12th and 1st centuries BC. The aim of this work was to obtain more information about the variation of the Earth's magnetic field in the Caucasus in this age range and, where possible, to contribute to the dating of the sites.

Paleomagnetic experiments including thermal and alternating field demagnetisation were carried out on nine combustion structures. Archaeointensity experiments were performed on six combustion structures and eight ceramic fragments with two different Thellier-type methods, the Coe and IZZI variants. Additional experiments to correct the effect of anisotropy of thermoremanence (ATRM) were also carried out. Previously, rock magnetism experiments including IRM acquisition curves, hysteresis loops and backfield curves, as well as thermomagnetic curves had been carried out on all studied samples to obtain information about the carriers of remanence and to find out if they were suitable for archaeointensity determinations.

Reliable paleomagnetic results could be obtained in all nine studied combustion structures. In addition, successful archaeointensity determinations were attained in six combustion structures and seven ceramic fragments. ATRM corrected archaeointensity results range between 64.8 and 94.3 µT. A preliminary archaeomagnetic dating was attempted in six combustion structures, but attainment of unambiguous dates is hindered by the lack of reliable archaeomagnetic data in the Caucasus region for the studied age range (XII BC - I BC). Currently, new 14C age determinations are being carried out on some of the studied materials to provide new high-quality archaeomagnetic data to the secular variation curve of the Caucasus.

Geological Society of America Abstracts with Programs. Vol. 54, No. 2

doi: 10.1130/abs/2022CD-373863

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