Paleomagnetic Laboratory (NIGGG - BAS, Bulgaria)
The residual magnetism of archaeological remains of burned clay is a
major source of information for the state of the Earth`s magnetic field
in the past. The recovery of the three main geomagnetic field`s
elements (defining its direction and intensity) recorded in well dated
archaeological materials, leads to the accumulation of an unique local
database that cannot be obtained by other methods. The Bulgarian
archaeomagnetic database can be considered as the longest local dataset
in the world, covering almost fully the last 8000 years going back to
Neolithic (Kovacheva et al. 2014, PEPI, 236, 79-94). The Bulgarian
reference curves are calculated based on over 300 reference points,
which are included in the GEOMAGIA50.v3 global database
(http://geomagia.ucsd.edu). Among the other archaeomagnetic
laboratories, the Sofia laboratory was the first to be engaged in the
simultaneous determination of the full geomagnetic field vector (D, I,
F) from one and the same material. Dedicated efforts of the team members
of Sofia Palaeomagnetic Lab aim further continuation and refinement of
the experimental methods for reliable determination of the geomagnetic
field elements and palaeosecular variation curves.
Another major thematic priority in the research activity of the team
members is obtaining reliable global and regional records of the past
climatic changes during the glacial Pleistocene through studies of
loess-paleosoil sequences. Detailed magneto-mineralogical and
magnetostratigraphic studies on a number of loess-paleosol profiles from
North Bulgaria have been carried out during the last 15 years, which
reveal the high sensitivity of the magnetic signature to climate change.
Further development of the environmental direction of the research topic
has been achieved by introduction of the magnetometric method for study
of the degree of anthropogenic pollution of soils, sediments, and dust
from urban areas. All of the above mentioned research directions utilize
the basic magnetic instrumentation available in the Laboratory.
It can be classified in three different classes:
- Laboratory equipment for mineral magnetic characterization of natural
materials
- Laboratory equipment for archaeomagnetic and palaeomagnetic studies
- Auxiliary lab instrumentation for physical characterization of the
materials – magnetic separation, milling, wet and dry sieving, soil pH
determination, etc.
More information on the major results and activities of the
Paleomagnetic Lab at NIGGG can be found at: www.niggg.bas.bg
