Geophysical Institute - Sofia, Bulgarian Academy of Sciences, Bulgaria (SOFI)
Role in the Network
  • Main speciality research areas: Rock-magnetic properties of the archaeological burnt clay, archaeointensity determination - acceptance criteria, secular variations of direction and intensity of geomagnetic field, application of archaeomagnetism in archaeological practice, environmental magnetism applied for detection of soil pollution and for palaeoclimatic investigations (magnetism of loess and soils).
  • Other factors: Well equipped laboratory with a long standing experience in the archaeomagnetic studies. The largest set of data containing both the past direction and intensity evaluations obtained from the same materials.
Research Linkage

Bi-lateral agreement with University of Rennes 1 and archaeomagnetic laboratories at Institut de Physique du Globe de Paris (St. Maur); bi-lateral agreement with the University of Geneva; links with Geophysical Centre at the Royal Meteorological Soc. (Belgium); links with the University of Tübingen (Germany) and the Geophysical Institute in Prague (Czechia).

Senior Scientist
Prof.  M. Kovacheva (e-mail: marykov@geophys.bas.bg, Tel.: 0035929713007, Fax: 0035929713005)
Young researcher   
Dr. Andy Herries (finished, now at Liverpool)
Project
Two archaeological sites were sampled from central Bulgaria to obtain palaeodirectional and palaeointensity data for two periods where the Bulgarian archaeomagnetic curve has a low density of data. At the Thracian site of Halka Bunar (late 3rd - early 4th century BC) three kilns, from a supposed pottery kiln complex, were sampled along with a fourth oven and fire destruction feature from another part of the site. A single oven was also sampled from the Medieval (11th -12th century AD) site of Zlatna Livada. A second aim at Halka Bunar was to establish the use of the kilns. This focused on identifying different atmospheres and temperatures of firing (oxidising, reducing and mixed) in the kilns. Detailed mineral magnetic tests were undertaken at both sites to look at their initial magnetic make up and alteration of the samples during heating, especially with regard to viscosity and the superparamagnetic/single domain boundary fraction. Consistent palaeodirectional (using both alternating field and thermal demagnetisation) and palaeointensity results using Thellier-Thellier analysis were recovered from both sites. Comparative microwave palaeointensity tests will also be undertaken.
Recent Publications
Lanos, Ph., Le Goff, M., Kovacheva, M. and E.  Schnepp, Hierarchical modelling of archaeomagnetic data and curve estimation by moving average technique. Geophysical Journal International, 160, 440-476, 2005.

Herries, A.I.R., Kovacheva, M. and N. Jordanova, Archaeomagnetic variability of an oven complex from the Thracian site of Halka Bunar, Bulgaria. Contributions to Geophysics and Geodesy, (Geophysical Institute Slovak Academy of Sciences), 34, 59, 2004.

Kostadinova, M. and A.I.R. Herries, Archaeomagnetic study of baked clay samples from the Thracian Sancutuary of ada Tepe, Bulgaria. Contributions to Geophysics and Geodesy, (Geophysical Institute Slovak Academy of Sciences), 34, 81, 2004.

Jordanova, N., Kovacheva, M. and M. Kostadinova, Archaeomagnetic investigation and dating of Neolithic archaeological site (Kovachevo) from Bulgaria, Physics of the Earth and Planetary Interiors, 147, 89-102, 2004.

Kovacheva, M., Hedley, I.,  Jordanova, N., Kostadinova, M. and V. Gigov, Archaeomagnetic dating of archaeological sites from Switzerland and Bulgaria, Journal of Archaeological Science, 31, 1463-1479, 2004.

Kostadinova, M., Jordanova., N., Jordanova, D. and M. Kovacheva, Preliminary study on the effect of waterglass impregnation on the rock-magnetic properties of baked clay, Studia geophysica et geodaetica, 48, 637-646, 2004.
Kovacheva, M., Balkan Peninsula and archaeomagnetism - a brief review, Jorunal of the Balkan Geophysical Society, 6, 173-178, 2003.
Jordanova, N., Kovacheva, M., Hedley, I. and M. Kostadinova, On the suitability of baked clay for archaeomagnetic studies as deduced from detailed rock-magnetic studies, Geophysical Journal International, 153, 146-158, 2003.
web-Link
http://www.geophys.bas.bg/