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1. Start
2. Objectives
3. Information for Archaeologists
4. Information for Archaeomagnetists
5. News
6. Meetings & Workshops
7. Laboratories
8. Downloads
9. Glossary
10. FAQ
11. Links
12. Databases
13. EU funding opportunities

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1. Start

AARCH is a Research Training Network funded by the European Commission within the 5th framework programme and co-ordinated by Dr. Cathy Batt in the Department of Archaeological Sciences, University of Bradford, UK. The project started in September 2002 and will run for 4 years. The network comprises 12 laboratories across Europe including the UK, Austria, Belgium, Bulgaria, Denmark, France, Greece, Spain and Italy. The funding is worth 1,484,946 € (£920,370) and will mainly be used in the appointment and training of young researchers.

For further information email the AARCH co-ordinators on aarch@bradford.ac.uk

Work supported by the European Community's Improving Human Potential Programme under contract No. HPRN-CT-2002-00219, AARCH
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2. Objectives

The Earth's magnetic field is a huge shield, protecting us against the bombardment of high energy particles. Changes of the field strength can influence the life on Earth and may act as evolutional sieve. Nowadays, the detailed mechanism of the magnetic field is still not yet completely clear, in particular the reversal process when the strength of the geomagnetic field is considerably reduced. However, there is an interest to extend the record of the geomagnetic field into the past and to combine the results with theoretical reversal  models. Lake, marine and continental sediments are often not reliable for an accurate registration of the geomagnetic field, because of delayed recording due to complex sedimentation environment and magnetic mineralogy. Archaeological material, however, does not have such implications and records the magnetic field more confidently, as the field recording process is different. Hence, it can be used for studies of the past geomagnetic field, but also as reliable dating tool for archaeological sites.

Many areas in the European Union (EU) are undergoing rapid economic expansion, inevitably involving the loss of our shared cultural heritage. Archaeological sites are often destroyed due to present day construction projects. Archaeological materials provide an irreplaceable record of the direction and intensity of the Earth's magnetic field in the past, using archaeomagnetic studies. At present, such records within Europe are irregular in both space and time. Some countries recognise the importance of such archaeologically based information, but wide variations exist in measures to retrieve and preserve such data, hindered by the lack of a skilled workforce.

The primary objective of this research project is:

  • To create a skilled workforce capable of collecting and measuring archaeomagnetic samples from archaeological and cultural sites, particularly those likely to be destroyed, or made inaccessible, as a result of economic development within the EU.

In order to achieve this objective, a number of activities are proposed:

  • Improve, unify and establish best practice in archaeomagnetic techniques to provide greater precision and consistency throughout the EU.
  • Optimise the information obtained and speed with which it is retrieved from archaeological sites.
  • Construct a spatially and temporally coherent record of the behaviour of the Earth's magnetic field during the last 10,000 years within the EU, based on common standards.

Research outcomes from the project will include:

  • A database for archaeomagnetic dating of other archaeological sites within and adjacent to the EU, thus establishing an absolute dating technique applicable to archaeological, geological, environmental and natural hazard situations, using materials not usually dateable by other methods.
  • Observations necessary for evaluating theories and models of the origin of the Earth's magnetic field, the relationship between the Earth's magnetic field and climatic change, the determination of past production rates for cosmogenic nuclides to be used for dating natural hazard features and the influence of the Earth's magnetic field on the penetration of harmful solar and cosmic radiation.
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3. Information for Archaeologists

Introduction
Archaeomagnetic applications in archaeology
Techniques
Guidelines

Preamble
This section is designed for an archaeologist with little or no previous experience of archaeomagnetism, but has, for example, found a burnt structure, such as a kiln or oven, and wishes to find out more about the archaeomagnetic technique.  Further details can be found by either clicking on the appropriate word in blue or by going back to the main menu. The glossary can be accessed for the definition of words in blue at any time and will then return to this section.

Introduction
Archaeomagnetism is mostly known for magnetic dating of burnt materials in an archaeological context.  This will be discussed first, followed by archaeomagnetic dating of other materials, such as plaster, sediments, paint, etc., and then other applications, such as reconstruction and provenancing.

When any material containing magnetic grains is heated above some 700 °C, it loses any previous remanent magnetisation.  As it cools down, the magnetic grains acquire a direction of magnetisation that is the same as that of the Earth’s magnetic field at that time and an intensity of magnetisation that is proportional to the strength of that field.  This magnetisation, acquired during cooling, is called a thermal remanent magnetisation (TRM) and has the remarkable property that most of it is preserved for thousands of years (and vastly longer) unless it is reheated or chemically changed. Such materials therefore retain a record of the direction and intensity of the Earth’s magnetic field from the time that the magnetisation was originally acquired.  Direct observations of the present Earth’s magnetic field only go back for some 400 years (<200 years for its intensity), but show that both the direction and intensity of this field change with time (secular variation). Therefore measurements of the magnetic properties of ancient fired materials can be dated by comparison of their directional and intensity properties with the known record of the Earth’s magnetic field properties. It is immediately obvious that this means that materials less than 400 years can be dated by  comparison with any nearby geomagnetic observatory records.  For older times, the principles are, of course, the same. However, there are no direct human recordings of the Earth’s magnetic field and so our knowledge of the behaviour of the Earth’s magnetic field depends on obtaining archaeomagnetic records from archaeological sites that have been securely dated by other means.  Thus archaeomagnetism not only provides a dating method for archaeologists but also provides a unique record of one of the major geophysical properties of the Earth.  More importantly, as the database increases, i.e. the number of securely dated archaeomagnetic sites increases, the ability to provide more reliable archaeomagnetic dates increases.  This makes this dating method unique as the greater the amount of data, the more precise the method becomes – unlikely all other scientific dating methods.
Archaeomagnetic applications in archaeology

Dating
Reconstructions/restorations
Sourcing
Geophysical surveying
Environmental analysis


Dating
Archaeomagnetic dating can be done using either the direction or the intensity of magnetisation (or better both) of burnt materials.  When these were originally heated in antiquity, they acquired a direction of magnetisation (magnetic remanence) in the same direction as the Earth’s magnetic field (also called geomagnetic field) at that site at that time.  This remanence also has an intensity of magnetisation that is proportional to the strength of the magnetic field at that time.  As the Earth’s magnetic field gradually changes both, direction and intensity, the direction and intensity of samples from the site can be dated by comparison with known direction and field intensity records for past times at that locality.  

    Such magnetic dating therefore depends on both the reliability of the sample observations and that of the known recorded direction and intensity of the Earth’s magnetic field during archaeological times.  Observatory measurements of the direction of the Earth’s magnetic field only commenced around 1600 AD, while intensity records only started in 1835 AD.  Consequently older dates depend on having available archaeomagnetic directional and intensity records from previous studies of well-dated archaeological sites.  Understandably, archaeologists usually request magnetic dating for sites that cannot be adequately dated by other means!  One of the major requirements for archaeomagnetic dating is therefore to obtain more observations from well-dated archaeological sites.  Fortunately, such well-dated sites can come from a wide region – within some 600 km of the site being investigated.  This is because the Earth’s magnetic field is fairly uniform (and therefore predictable) over an area of some 1 000 000 km2. It also makes archaeomagnetic dating unique in that, the more data that becomes available, the more precise the record becomes and hence this dating method is continually increasing in precision.  

    Another important consideration is that this technique is extremely good at testing the synchroneity of “magnetic” events within this 1 000 000 km2 region.  Two sites, e.g. burnt destruction levels several hundred km apart, that were fired at the same time will have identical directions and ancient field intensities.  That is, of course, identical within the limits of the technique.  However, these can be quite precise and are independent of the actual age.  For example, Minoan destruction sites (LMIB) in central Crete have identical directions and ancient intensities as the ‘Minoan’ ash levels on Santorini, 120 km to the North, enabling the synchroneity of the events to be established within some 10-20 years some 3 500 years ago.  If the corresponding directions and ancient field intensities can be established within the Egyptian chronology in Lower Egypt or ancient Greece, then absolute dating could be determined within the Egyptian or pre-Hellenic chronologies.   Here you find an example of an archaeomagnetic dating


Reconstructions/restorations
Archaeomagnetic reconstructions/restorations are based entirely on the directional magnetic properties of samples from a site.  They are based on the structure or object having been magnetised in a relatively uniform Earth’s magnetic field at the time that it was heated.  Each sample, e.g. a potsherd, will have a direction of magnetisation; all samples directions were originally aligned when the original pot was fired and so the pot, in this case, can be re-assembled by re-aligning each shard magnetisation.  (Needs illustration).  Similar samples from a floor would all have preserved the direction of magnetic North when they cooled after being heated (e.g. in a kiln or burnt structure), or samples from a wall will all have the same direction of North and the same magnetic inclination (Needs illustration). 

Shards from a spherical pot can therefore be uniquely reassembled.  Samples from floors and walls can be at least oriented in their original positions.  (It should be stated that such magnetic methods only supplement the standard methods of reconstruction and are usually only practical when, for example, only a few non-contiguous shards are available; these may well enable the shape of the pot to be assessed.)  This technique has particular significance in determining the original orientation of key elements in a structure, e.g. the location of wedges in a smelting system. 

Another example is that when most Roman coins were hot-dipped (silvered), this was apparently undertaken while the plane of the coin was vertical.  Similarly, the orientation of statues, when originally cast, can be assessed (but usually using samples from their burnt clay core).


Sourcing
Archaeomagnetic sourcing can be undertaken using the magnetic properties of samples of, for example, obsidian. The intensity of magnetisation, magnetic susceptibility and, for example, high field magnetic saturation of samples can be measured very quickly and hence cheaply.  These have been successful in predicting new obsidian sources, subsequently confirmed by neutron activation analyses.


 Geophysical surveying
Archaeomagnetism & geophysical surveying are interlinked as the sources of magnetic anomalies, in particular, are directly related to areas that have been heated and hence magnetised in the past magnetic field.  Anomalies associated with such magnetisation have different orientations compared with the magnetisation induced in these materials by the present-day geomagnetic field at the time of the survey.  The separation of such anomalies is therefore vital for more realistic interpretations of the anomaly patterns and may even allow an estimation of the possible magnetic age of some structures under ideal conditions. 



Environmental analysis
Archaeomagnetism & environmental analysis are similarly interlinked as the magnetic properties of soils, for example, are highly dependent on the oxidation conditions to which they have been subjected.  Soils that have been burnt during deliberate or accidental firing of the vegetation have distinctly different properties, enabling the soil wash from such area to be identified in drainage areas, etc.

The example below shows coercivity spectra (of magnetic remanence) for one and the same material, but baked at different temperatures and under different oxidation conditions. The samples originate from the wall of the combustion chamber of a Roman pottery kiln near Bruyelle (Belgium), which was dug into loess. The blue graph represents the spectrum of non baked loess (source material).

When the source material is baked under oxidising conditions, as met in the interior of the wall (~ 65 mm away from the inner side of the combustion chamber), chemical reactions occur, altering the magnetic mineral assemblages present in the sample. Consequently, the coercivity spectrum changes considerably, as it is displayed by the red graph. The remanent magnetisation is about 14 times stronger than those of the source material (blue graph). Laboratory re-heating experiments indicate that this sample had not been heated above 450 °C.

Much higher temperatures (often around 1000 °C or above) are reached inside the combustion chamber of a kiln. The surface of the kiln wall is in contact with the fuel, and a mainly reducing atmosphere is present. Under these conditions another type of magnetic mineral assemblages (see black graph) is produced during baking. The remanent magnetisation is about 170 times higher that those of the source material.


Figure D: Coercivity spectra of unbaked loess (blue), of baked loess under oxidising conditions (red) and  of baked loess under reducing conditions (black). The spectra are displayed normalised (= the area below each graph equals 1) and on a logarithmic field scale. The thickness of the graphs corresponds to the measurement error. Data from Spassov and Hus (2005).

Techniques

Archaeomagnetic sampling
Archaeomagnetic directional dating - an example

Archaeomagnetic sampling

Suitable Materials
 Sites
An example of archaeomagnetic dating
After some sample preparation, the direction (declination, inclination) and intensity (latter depends on the instrumentation of the individual laboratories) of the samples magnetic remanence is measured in the laboratory with a magnetometer. Several samples are measured from one archaeological artefact, in order to obtain a well defined mean and the error.


The following example is taken from Kovacheva et al. (2004) and concerns a more or less circular pottery kiln from Reinach (Switzerland) consisting of large stones. As stones are not suitable for archaeomagnetic dating, baked clay lining the kiln walls was sampled. The archaeological age proposed by context dating is the second half of the 8th century AD.



The measured average direction of the remanence at the archaeological site is:


Figures C and D: Inclination and declination plots versus time. The solid horizontal lines in both graphs represent measured inclination and declination of the archaeological site of unknown age. The dashed horizontal lines are the error of the measurement. The inclination and the declination of the reference curve (= known time variation of D and I of the Earth's magnetic field) is plotted as well, together with its error. The green shaded areas correspond to the probability densities at a 95% confidence level of possible dates.
Figure. C: Inclination plot. The measured inclination meets the reference inclination curve 2 times and would suggest two possible ages  642-896 and 1647-1807 AD (green shaded intervals).

modified from Kovacheva et al. (2004)
Figure D: Declination plot. The measured  declination, meets the reference declination curve also two times, but suggesting two different possible ages  774-932 and 1042-1618 (green shaded intervals). In order to obtain the most probable solution, the probability densities of inclination and declination are combined (see Fig. E).

modified from Kovacheva et al. (2004)


Figure E: Age probability density of inclination (top) and declination (middle) and their combination (bottom).  When both probability densities are combined, the only possible age interval is: 753 - 901 AD, which is comparable with the archaeological age (2nd half of th the 8th century AD).

modified from Kovacheva et al. (2004)
In case the, that the archaeointensity of the site has also been determined, it can be used as the third geomagnetic element in the same way as it has been demonstrated here for declination and inclination. Such dating examples, using declination, inclination and intensity, can be found in Kovacheva  et al. (2004).

Reference
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.


Guidelines and supplementary information

Requirements
Hazard assessment
Costs
Further reading



Requirements
... for archaeomagnetic dating
The archaeomagnetist will normally require at least half a day to undertake the sampling, make the appropriate notes, etc. The optimum time for both the archaeomagnetist and the archaeologist is usually before the structure is removed or destroyed. However, there are clearly practical problems for both partners in finding such a common time! As such structures are of generally little value, after having been fully recorded, it is common that the archaeomagnetist can effectively assist in destroying the remaining feature (under the supervision of the archaeologist) to expose any underlying features.

However, if the site is to be preserved or reconstructed, then the archaeomagnetist must be advised of this so that the least invasive sampling methods can be used. For example, a brick can be removed to enable samples to be taken from immediately below it, and the brick then replaced to hide the sampling. As a variety of sampling methods are available, this must be discussed with the archaeomagnetist before they arrive at the site!

The samples to be taken should not have been treated with, for example, a preservative and should, as far as practicable, be in their pristine state.

The local site archaeologist will normally be responsible for assessing any hazard during sampling. The archaeomagnetist must obey all instructions of the site archaeologist on this matter. (see Hazard Assessment)


... for archaeomagnetic directional dating and reconstruction
The fundamental requirement is that the object to be dated (let’s say the base of a kiln) should be undisturbed since it was originally fired. The archaeomagnetist usually says that the feature must be “in situ” but this term is much stricter than the conventional archaeological meaning of not being external to the site. It is vital that the kiln, in this example, has not been disturbed or, if tilted because of differential subsidence or kiln-wall fall out/in, etc, or that such motions can be determined to within 1º. (Conversely, archaeomagnetism can be used to distinguish such motions.) This also means that parts of the structure should not have been reconstructed, including the removal and even immediate replacement of, for example, one of the bricks. Please advice the archaeomagnetist of any such suspect areas.


... for archaeointensity dating, geophysical and environmental analysis

There are few special requirements, but the archaeomagnetist will be primarily interested in the most strongly fired parts of the structure or object for intensity dating and geophysical interpretation. Ideally the material should also be uniform in colour and composition.



Hazard assessment
currently under development


Costs
Although equipment and instruments are relatively cheap compared with radiometric dating techniques, the actual costs for directional dating is labour intensive and hence similar.  Intensity dating has been more automated, but the equipment costs are higher, so that the costs are currently also similar to radiometric methods.
However, there are few commercial companies involved in this method.  Most of the laboratories are currently in academic or government agencies.  In these cases, some of the running costs may well be born by the agency, in which case the minimum charge could be purely the costs of travel to the site and accommodation if necessary.  These can only be established by contacting the nearest available institution (see Archaeomagnetic Laboratories)


Further reading
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4. Information for Archaeomagnetists

Introduction
Archaeomagnetism is the investigation of archaeological sites or objects with geophysical methods based on the interaction between magnetic minerals of the archaeological object and the Earth's magnetic field. The major applications/research topics of archaeomagnetism are magnetic prospection surveys (magnetic mapping) of buried archaeological objects and studies of the geomagnetic field as recorded by the magnetic minerals of the archaeological material. Latter application being the main topic of the AARCH training network.

Baked material, such as baked clay, bricks and tiles are used to obtain direction and intensity of the ancient geomagnetic field during archaeological periods of time. After precise determination of declination, inclination and intensity a reliable date of the archaeological site can be obtained from secular variation curves. Beside the aspect of archaeomagnetic dating, secular variation master curves from different regions (area of about 250 000 km2) yield valuable information about the dynamics of the Earth's magnetic field of the past.


Archaeomagnetic sampling
under construction

Archaeomagnetic measurements
under construction

Data analysis
under construction

Archaeomagnetic dating
under construction
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5. News
Spring 2006
 Final AARCH workshop 10th of May until 14th of May 2006.
Autumn 2005
AARCH workshop 4 was held at Rennes, 26th of October until 1st of November 2005.
Spring 2005                                
The AARCH workshop 3 & the midterm meeting was held at Madrid, Thursday 18th of March  until Tuesday 21st of March 2005. 
New year 2005
 Welcome Assunta Trapanese (Bradford) and Andrzej Rakowski (Madrid) - We wish everybody a Happy and Peaceful New year and a lot of success!
Autumn 2004
 Welcome Mimi Hill (Rennes), Irene Zananiri (Bradford), Calin Suteu (Bradford) and Ulf Winkler (Plymouth).
Autumn 2004
 Good bye Elina Aidona (Leoben) and Andy Herries (Sofia).
Spring 2004
 Good bye Clare Peters (Aarhus).


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6. Meetings & Workshops
Workshop 1 Liverpool
 07. 05. - 10. 05.  2003
  • Sessions about treatment strategy, palaeointensity & microwave treatment, funding & co-operation, sampling & collection
  • Invited talks by Alberto Incoronato and Paul Linford
  • Business meeting
  • Field trip to a Medieval iron smelter at Plas Tan y Bwlch (Snowdonia) and to Bronze Age copper mine Great Orme (Llandudno)








Workshop 2 Thessaloniki 29. 03. - 31. 03. 2004
  • Young researchers presented first results
  • Invited talks by Ted Evans and Danis Nourgaliev
  • Lectures by Philippe Lanos, Elisabeth Schnepp and Roberto Lanza
  • First results of interlaboratory calibration
  • Business meeting
  • Field trip to the archaeological site at Dion (Classical period) and the Royal Macedonian tombs at Vergina








Practical training Olimpiada (Greece)
 01. 04. 2004
  • Ted Evans and Philippe Lanos demonstrated different sampling and orientation techniques for taking samples of different sizes.








Workshop 3
& Mid-Term Review
 Madrid
 18.03. - 21. 03. 2005
The primary topic of the AARCH workshop 3 was Analysis. Invited speakers: Elisabeth Schnepp and Karl Fabian. The Mid-term Review meeting will be attended by Prof. Robert Nesbitt the representative of the European Commission.








Workshop 4
 Rennes
 26.10. - 1.11. 2005
The scientific topic of the AARCH workshop 4 was dedicated to Databases.  Invited speakers: Andy Jackson, Fannete Laubenheimer, Caitlin Buck








Final Meeting
 Lipari
 10.05.-16.05. 2006


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7. Laboratories

Interlaboratory calibration
AARCH is a network which involves several laboratories throughout Europe that have the same aim to measure the Earth’s magnetic field in the past as it is revealed by archaeological material and contribute this way to the rescue of cultural heritage.

However, to obtain this aim through a fruitful  collaboration  of  all the network laboratories, it  is  important  that  all  of  them  “speak”  the  same language! Often, the wide range of equipment and software used by  each  laboratory,  the differences on measurement procedures  or  units  used,  make it difficult  to compare the results obtained. For this reason AARCH  team  has  started  an  inter-laboratory  calibration check, involving all the AARCH member laboratories.


Phase 1 - measurement equipment
In October 2003,  the  AARCH  team  at  Torino oversampled a Roman kiln at Canosa (southern Italy) in order  to  provide specimens  for an inter-laboratory  instrument  check.   Five cylindric specimens of standard  size  were  prepared  from  five  independently oriented bricks. The specimens were  first  measured  at  the  palaeomagnetic laboratory of the University of Torino several times in a time period  of  a month in order to check for any significant viscous magnetization  acquired. Afterwards,  the  specimens  were  sent  to  the  other  laboratories  to  be measured. Each  laboratory  was  asked  to  measure inclination, declination and intensity of the natural remanent magnetisation (NRM) and  the  magnetic  low-field susceptibility at  low frequency.

Up to now, replies  have  been  received  from  9  of  the  12  AARCH laboratories and a first discussion of the results was already made  at  the AARCH workshop 2 at Thessaloniki, in April 2004.  In  most  cases  magnetic susceptibility and  intensity  results  show  a  good  agreement  among  the different laboratories, but as far as  the  inclination and declination  results  are  concerned,  some  small discrepancies have been pointed out. Their significance  should  be  further examined when all the laboratories will  have  measured  the  specimens  and when the samples will have been remeasured at laboratory of Torino. A final discussion and interpretation of the results is planned for the AARCH workshop 3 in Madrid (March 2005).

Download the inter-laboratory calibration report phase 1 as pdf-file.

For further information contact Evdokia Tema: evdokia.tema@unito.it



Phase 2 - data analysis

The second phase of the interlaboratory calibration concerns the analysis of demagnetisation data. The AARCH team at Madrid provided two data sets of thermally and of alternating field demagnetised samples from two archaeological sites. Each laboratory is asked to calculate the mean direction of both sites. The outcome has been discussed at the AARCH workshop 3 in Madrid (March 2005).

Download the inter-laboratory calibration report phase 2 as pdf-file.

For further information contact Gregg McIntosh or Gianluca Catanzariti:  gregc@fis.ucm.es, gcatanza@fis.ucm.es


The AARCH laboratories
Bradford
 Aarhus
 Liverpool
Leoben
 Rennes
 Plymouth
Dourbes
 Thessaloniki
 Torino
Sofia
 Madrid
 Napoli





Bradford, Department of Archaeological Sciences, University of Bradford, UK (BRAD)
Role in the Network
  • Main speciality research areas: International reputation for the integration of archaeology and science, specifically scientific dating methods, magnetic properties of archaeological materials, archaeological sediments, prospection methods. All areas supported by extensive field and laboratory instrumental facilities.
  • Other factors: One of largest groups of pre- and postdoctoral students in British archaeology. Involvement in many major archaeological field.
  • Bradford hosted meeting and the AARCH workshop 1 with Liverpool. The network co-ordinator heads the Bradford team.
Research Linkage
Links with Plymouth, UK. Co-operation with English Heritage (Archaeometry Section), Oxford University (Research Lab. Archaeology & History of Art), numerous professional archaeological units and trusts.
Senior Scientist
Dr. C. M. Batt (e-mail: c.m.batt@Bradford.ac.uk, Tel.: 00441274233533, Fax: 00441274235190)
Young researcher
Dr. Irene Zananiri, Calin Suteu, Assunta Trapanese
Projects
Calin Suteu
My research project in Bradford will be concerned upon the theoretical and practical methodology of constructing the Romanian reference system and also upon its maintenance, all taking into consideration the examples found in UK and in Europe mainly. It will also present a side-project concerning the introduction of this dating method to the Romanian archaeologists and the establishment of a national system of reporting and collecting AMS samples from archaeological excavations in progress.


Assunta Trapanese
The use of various sampling techniques for archaeomagnetic dating is a difficult issue in distinguishing between the errors occurring in the field and those caused by the laboratory measurement procedures. The current sampling techniques are applied on four well-dated archaeological sites and on a modern fire. The geophysical survey will support the detailed sampling location. The use of magnetic remanence measurements along with microscopic and granulometric observations will make possible the comparison between the different collections, in order to define the guidelines on the best practice of the fieldwork strategy.


Irene Zananiri
The currently used British calibration curve was produced by A.J. Clark et al. in 1988, using archaeomagnetic measurements from 92 features, over 200 direct observations of the geomagnetic field and measurements of magnetic directions from lake sediments. It covers the period from 1000 BC to 1975 AD, and consists of a line drawn freehand through the available dated points. As it is clear, many uncertainties are incorporated due to a) Lack of error representation, b) Lack of representation of the density of data, c) Use of freehand fitting technique. Several new ideas have been proposed lately in order to create a more reliable calibration curve. My research project will involve:

a) Collection of all existing UK data, which will be incorporated in the existing dataset. Information about the accuracy of their archaeological 
     date will be included as this matter is crucial about the construction of the curve.
b) A thorough research of previous and newly suggested techniques concerning the creation of a calibration curve.
c) Several techniques will be applied to the new dataset in order to decide the most appropriate one for the case of the UK.
d) An effort to apply the same or a similar approach to the existing Greek data (though much fewer, and mostly intensities).
Recent Publications

Tarling, D.H., and C.M. Batt, Archaeomagnetic Applications for the Rescue of Cultural Heritage (Abs.). Contributions to. Geophysics and Geodesy, 134, 154, 2004.

Batt, C. M., Preliminary investigations into the acquisition of remanence in archaeological sediments. In: Palaeomagnetism and Diagenesis of Sediments (Eds. Tarling, D.H. and P. Turner), Special Publication of the Geological Society of London, 151, 9-19, 1999.

Batt, C.M., The British archaeomagnetic calibration curve: an objective treatment, Archaeometry, 39, 153-168, 1997.
Web-Link



Leoben, Institute Geophysics, University of Leoben, Austria (LEOB)
Role in the Network
  • Main relevant speciality research areas: consolidation and conservation of unconsolidated samples, underground sampling, prospection, environmental magnetism, mineral magnetism, instrumentation development.
  • Other factors: A major instrumentation facility in a building isolated from physical and electromagnetic disturbances, including accommodation for researchers. Access to microprobe facilities. A key location for early iron smelting and access to nearby Associated Countries.
Research Linkage

Team co-operation with Plymouth. Formal links with University of Munich for magnetic mineralogy

Senior Scientist

Prof. H. J. Mauritsch (e-mail: hermann.mauritsch@notes.unileoben.ac.at, Tel.: 0043 3842 402864, Fax: 0043 3842 402663)

Young researcher    
Project
  • Development of new sampling techniques, particularly for furnaces and roasting hearths
  • Consolidation techniques for weakly consolidated samples in situ using polymers.
  • Setting up a archaeo-spinner for larger samples
  • Investigating bronze age smelting activity.
  • Investigating Roman walls from the LIMES near Vienna.
Recent Publications
Chech, B. and G. Walach, Medieval gold and silver mining in the Hohe Tauern (Austria); Results of archaeological/archaeometric investigations. Proceedings of the 5th International History Congress, Milos Island, Greece, 2000.

Scholger, R., Heavy metal pollution monitoring by magnetic susceptibility measurements, applied to sediments of the River Mur, European Journal of Environmental and Engineering Geophysics, 3, 25-37, 1998.
Web-Link

Dourbes, Centre De Physique Du Globe De L'IRM, Belgium (RMI)
Role in the Network
  • Main speciality research areas: secular variation of the geomagnetic field, Quaternary magnetostratigraphy, environmental magnetism, soil and loess magnetism, geomagnetism and climate, magnetic refraction, prospection, anisotropy of archaeological materials.
  • Other factors: The division Environmental Magnetism of the Belgian Royal Meteorological Institute is hosted with the magnetic observatory of IRM in the Centre de Physique du Globe, in a superb environment in the heart of Europe (province of Namur). CPG has experience in training in fundamental and applied Quaternary and archaeomagnetism.
Research Linkage
  • Links with the Free University of Brussels and Institute of Geophysics in Sofia, Bulgaria. Co-operation with Service de l'Archéologie du Ministère de la Région Wallonne, Institute for the Archaeological Heritage of the Flemish Community (IAP) and archaeological services in Belgian federal institutions and universities. Research interests in China, Syria and loess areas
Senior Scientist

Prof. J. J. Hus (e-mail: jhus@oma.be, Tel.: 003260395482, Fax: 003260395423)
Young researcher   
Project
    Palaeointensity determination and investigation of rock magnetic properties of samples from Carolingian/Merovingian and Roman sites. Investigation of soils in archaeological sites.
Recent Publications
Hus, J., Geeraerts, R. and J. Plumier, On the suitability of refractrory bricks from a medieval brass melting and working site near Dinant (Belgium) as geomagnetic field recorders, Physics of the Earth and Planetary Interiors, 147,103-116, 2004.

Hus, J., Geeraerts, R. and J. Plumier, Origin of deviations between the remanent magnetisation and inducing geomagnetic field direction in kilns and implications on archeomagnetic dating, Contributions to Geophysics and Geodesy, (Geophysical Institute Slovak Academy of Sciences), 34, 63-64, 2004.


Hus, J., Ech-Chakrouni, S., Jordanova, D. and R. Geeraerts, Archaeomagnetic investigation of two Mediaeval brick constructions in North Belgium and the magnetic anisotropy of bricks. Geoarcheology, 18, 225-253, 2003.

Hus, J., Ech-Chakrouni, S. and D. Jordanova, Origin of magnetic fabric in bricks: its implications in archaeomagnetism, Physics and Chemistry of the Earth, 27, 25-31, 1319-1331, 2002.

Hus, J. and Geeraerts, R., The direction of geomagnetic field in Belgium since Roman times and the reliability of archaeomagnetic dating Physics and Chemistry of the Earth, 23, 997-1007, 1998.
Web-Link


Sofia, 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., Schnepp, E., 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


Aarhus, Department of Earth Sciences, Geophysical Laboratory, University of Aarhus, Denmark (UAA)
Role in the Network
  • Main speciality research areas: Archaeological construction, geomagnetic secular variation and databases, bulding orientation analysis and interpretation.
  • Other factors: Long record of training in archaeomagnetism, Extensive archaeomagnetic studies in northern Europe and external to Europe.
Research Linkage

Links with Centres National de la Recherche Scientifique, Franceö Institute of Prehistory and Medieval Studies, Moesgaard, Denmark. Also links to palaeomagnetic groups in Warsaw, Moscow, St. Petersburg, Helsinki, Stockholm, Trondheim and Milan.

Senior Scientist
Assoc. Prof. N. Abrahamsen (e-mail: Abraham@geo.au.dk, Tel.: 004589424335, Fax: 004586101003)
Young researcher
Dr. Clare Peters (finished, now at University of St. Andrews, Scotland, UK)
Project

Recent Publications
Abrahamsen, N., Jacobsen, B.H., Koppelt, U., de Lasson, P., Smekalova, T. and O. Voss, Archaeomagnetic investigations of Iron age slags in Denmark, Archaeological Prospection, 10, 91-100, 2003.

Riisager, P. and N. Abrahamsen, Paleomagnetic Errors related to Sample Shape and Inhomogeneity. Earth Planets & Space 55, 83-91, 2003.

Riisager, P., Abrahamsen, N. and J. Rytter, Research Report: Magnetic investigations and the age of a Medieval kiln at Kungahälla (South-west Sweden). Archaeometry 45, 665-674, 2003.


Gram-Jensen, M., Abrahamsen, N. and A. Chauvin, Archaeomagnetic intensity in Denmark, Physics and Chemistry of the Earth, 25, 525-531, 2000.

Koppelt, U., Abrahamsen, N., Dittrich, G., Frandsen, J. and P. de Lasson, Micromagnetic investigations of medieval settlement structures at Kalø castle (Denmark), Journal of Applied Geophysics,  41, 145-156, 1999.
Web-Link


Rennes, Laboratoire D'archeomagnetisme, Centre National De La Recherche Scientifique, France (CNRS)
Role in the Network
  • Main speciality research areas: Processes of magnetic remanence acquisition, magnetic refraction and anisotropy, cooling rate effects, geomagnetic secular variation, chronological data processing, heritage management.
  • Other factors: A very well equipped laboratory with extensive experience in research training.
  • Rennes will host Network Meeting and Workshop 4.
Research Linkage
  • Bi-lateral agreement with Sofia, Bulgaria. Links with University of Aarhus, Denmark. Co-operation with archaeomagnetic laboratories at Institut de Physique du Globe de Paris (St. Maur) and Montpellier; Links with Ministère de la Culture; Institut National de Recherches Archéologiques Préventives; Research interests in France, Spain, Italy, Israel, etc.
Senior Scientist
Prof. P. Lanos (e-mail: Philippe.Lanos@univ-rennes1.fr Tel. 00332 23 23 56 39 Fax: 00332 23 23 60 90)
Young researcher     
Dr. Mimi Hill
Miriam Gómez-Paccard
Project
Mimi Hill
Archaeomagnetic investigations on samples from the first millennium BC. Several samples have been collected from two archaeological sites in Italy: a Greek site near Metaponto,  Bascilicata (7th century BC ),  and a site at Albinia, Toscane (2nd century BC).

Miriam Gómez-Paccard
Archaeomagnetism in France during proto and prehistoric times
Recent Publications

Lanos, Ph., Le Goff, M., Kovacheva, M., Schnepp, E., Hierarchical modelling of archaeomagnetic data and curve estimation by moving average technique. Geophysical Journal International, 160, 440-476, 2005.


Chauvin A., Garcia Y., Lanos Ph. and F. Laubenheimer,  Paleointensity of the geomagnetic field recovered on archaeomagnetic sites from France, Physics of the Earth and Planetary Interiors, 120, 111-136, 2000.

Lanos, Ph., Kovacheva, M. and A. Chauvin, Archaeomagnetism, methodology and applications: implementation and practice of the archaeomagnetic method in France and Bulgaria,  European Journal of Archaeology, 2, 365-392, 1999.
Web-Link


Thessaloniki, Department of Geophysics, Aristotle University of Thessaloniki, Greece (THES)
Role in the Network
  • Main speciality research areas: rock magnetism, prospection, remanence acquisition, geomagnetic secular variation and archaeological reconstructions and applications.
  • Other factors: Located in a key area for Classical (pre Greek to post Roman) and Byzantine times.
  • Thessaloniki  hosted the AARCH Workshop 2 (29. 03.  - 01. 04. 2004).
Research Linkage
  • Links with Sofia, Bulgaria; Plymouth, UK; Leoben, Austria. Co-operative links with I.P.G. (Strasbourg), E.N.S. (Paris) and Rome (Roma Tre).
Senior Scientist
Assoc. Prof. D. Kondopoulou (e-mail: despi@geo.auth.gr, Tel.: 00302310998485, Fax: 00302310998485)
Young researchers
Dr. Simo Spassov (finished, now at Centre de Physique du Globe de l'IRM, Dourbes, Belgium),
Emanuela de Marco
Projects
Simo Spassov
The temporary record of the Earth's magnetic field intensity in Greece is solely based on material from archaeological sites. Data from historical lava flows on Santorini would complete the Greek data set and provide additional control points. Within this frame, eight lava flows ranging in time from 46 AD until 1950 AD and volcanic clasts from the Minoan eruption 1640 BC were sampled. Archaeological material from Hellenistic pottery kilns has been sampled, too. Magnetic remanence carrying minerals often alter during thermal treatments, such as during the procedure for determination of the ancient magnetic field. The samples were tested for thermal stability (thermomagnetic analyses of magnetic susceptibility and magnetic remanence). First results show that the lava samples are thermally stable and may be useful for absolute ancient field intensity determination. The archaeological material is thermally stable, too. In a next step the absolute ancient field intensity will be determined using Thellier-Thellier and microwave analysis.

Emanuela De Marco
The Greek secular variation curve is not very well defined, concerning declination and inclination measurements. The primary activity is to study archaeomagnetic directions of many kilns in Greece, in order to construct, a  temporary record of geomagnetic field directions, which can be used in future for archaeomagnetic dating in Greece. Until now four archaeological sites have been sampled in Northern Greece; they belong to the Classical - Hellenistic period , so the time span under investigation ranges from the 4th to the 1st centuries BC. The results of the archaeomagnetic directions that have been recorded by these burnt clay materials (like pottery and ceramic bricks and tiles, but mostly high fired wall- and floor-materials from kilns and hearts), as well as the rock-magnetic properties, reveals that these materials is very suitable for archaeomagnetic study. At the same time, data from previous works on archaeomagnetic directions in Greece are compiled, in order to fulfill the database.
Recent Publications

Tarling, D.H., Kondopoulou, D., Soles, J.S. and V. Spatharas, Minoan Directional Archaeomagnetic Data from LMIB Sites at Mochlos and Kalinomouri, Crete. Geophysical Research Abstracts, 5, 3963, 2003.


Kovacheva, M., Spatharas, V. and I. Liritzis, New archaeointensity results from Greek materials, Archaeometry, 42, 415-429, 2000.

Spatharas, S., Kondopoulou, D., Liritzis, I. and G.Tsokas, Archaeointensity results from two ceramics kilns from Northern Greece, Journal Balkan Geophysical Society, 3, 67-72, 2000.

Web-Link


Madrid, Facultad De Cc.Fisicas, Universidad Complutense De Madrid, Spain (UCM)
Role in the Network
  • Main speciality research areas: Soils and sediment magnetisation, magnetic properties, archaeological ceramic technologies, geomagnetic secular variation and 4 dimensional (space and time) geomagnetic modelling.
  • Other factors: The largest team of the Network. Ideally located for studies during Moorish times when the extant European records are poor.
  • Madrid will host the AARCH workshop 3 and the AARCH midterm meeting
Research Linkage
  • Team bi-lateral agreements with Plymouth, UK and Leoben, Austria. Formal links with Madrid Science Foundation, Spanish National Science Foundation.
Senior Scientist

Prof. M.L. Osete (e-mail: mlosete@fis.ucm.es , Tel.: 0034 91 3944396, Fax: 0034 91 3944398)

Young researchers  
Gianluca Catanzariti
Dr. Andrzej Rakowski
Project
Gianluca Catanzariti
The inhomogeneous geographical distribution and existing time gaps (especially between the  VI  and IX century) in the Spanish  archaeomagnetic database are the principal problems that need to be solved.  On  the  one hand, Spain has a very  rich  archaeological  heritage  and,  as  result  of economic development, a wide variety of remains is  continually  discovered. Unfortunately,  in  many  cases newly  discovered  sites  need  to  be destroyed as part  of  this  development  and  our  activity  is  especially oriented to reduce this loss of information.
 
Within this framework, new contacts with Iberian  archaeologists  have  been established, and about 15 new sites  have  been  sampled.  This  number  will continue to increase as new sites are identified and  sampled.  In  addition to refining and enlarging the Iberian secular variation curve, some  of  the new sites are of interest in testing the precision  of  the  archaeomagnetic method.

A detailed investigation of the magnetic properties of the sampled  material is carried out. Blocking temperature and  coercivity  spectra  of both, the natural  and  laboratory-imparted  remanences  are used  to define the mineral phases carrying the remanent magnetisation and to  choose the best demagnetisation technique. These experiments are complemented  by magnetic hysteresis measurements. Further information will  be  provided  by detailed thin  section, electron  microscopy  and  other  compositional analyses such as X-Ray diffraction.

Andrzej Rakowski
The aim of my study is "Anthropogenic changes of radiocarbon concentration in modern wood". I am a specialist in radiocarbon dating, and I hope my knowledge in this matter can help solving problems concerning the chronology of archaeological sites which were or will be examined. Using atomic mass spectroscopy (AMS for short), extremely small carbon samples (containing < 1mg of organic Carbon) are necessary  for dating only. It can be useful for dating for example soot from the furnace or microfossils deposited in lake sediments in order to build a precise chronology for the site.
Recent Publicatios
Núñez, J.I., Osete, M.L., Ruiz-Martinez, V.C., Fabien, A. and D.H. Tarling, A First Secular Variation Curve for the Iberian Peninsula. Geophysical Research Abstracts, 5, 13381, 2003.

Núñez, J.I. Osete, M.L. and  D. Bernal, Primera curva de Variación Secular a partir de datos paleomagnéticos para la Península Ibérica. 2&ordf; Asamblea Hispano-Portuguesa de Geodesia y Geofísica, Ed.: Instituto Geofísico do Infante D. Luís, Portugal. 309-310, 2000.

Núñez, J.I., Osete, M.L. and D. Tarling, Datación arqueomagnética del taller: El horno del sector D. El paleomagnetismo como técnica de datación arqueológica. In: Excavaciones arqueológicas en los alfares romanos de la Venta del Carmen (Los Barrios, Cádiz). Coeditado por Universidad Autónoma de Madrid y el Ayuntamiento de los Barrios (Cádiz). 307-328, 1998.
Web-Link


Liverpool, Geomagnetism Laboratory, University of Liverpool, UK (LIVE)
Role in the Network
  • Main speciality research areas: International reputation for Archaeointensity and Palaeointensity studies. International centre for microwave analysis of ceramics and rocks.
  • Other factors: One of largest and best-equipped archaeomagnetic/palaeomagnetic laboratories in Europe. Major research concentrating on archaeointensity and palaeointensity analysis in order to define local master curves for use in dating and improving our understanding of the behaviour of the geomagnetic field.
  • Liverpool  co-hosted with Bradford the AARCH workshop 1.
Research Linkage
  • Links with major laboratories worldwide.
Senior Scientist
Prof. J. Shaw (e-mail: shaw@liv.ac.uk, Tel.: 00441517943463, Fax : 00441517943464)
Young researchers  
Dr. Lluís Casas (finished, now at Universitá degli Studi di Napoli, Italy)
Project
  • EU archaeointensities from historic lava flows
  • Development of an archaeointensity standard sample
  • Analysis of central European ceramics
Recent Publications
Böhnel, H., Biggin, A.J., Walton, D., Shaw, J. and J.A. Share, Microwave palaeointensities from a recent Mexican lava flow, baked sediments and reheated pottery, Earth and Planetary Science Letters, 214, 221-236, 2003.

Pan, Y., Shaw, J. , Zhu, R.X. and M.J. Hill,  Experimental reassessment of the Shaw palaeointensity method using laboratory-induced thermal remanent magnetization, Journal of  Geophysical Research, 107, B7, 10.1029/2001JB000620, 2002.

Hill, M. J., Gratton, N. and J. Shaw, A comparison of thermal and microwave palaeomagnetic techniques using lava containing laboratory induced remanence, Geophysical Journal International, 150, 1-7, 2002.
Web-Link

Plymouth, Department of Geological Sciences, University of Plymouth, UK (PLYM)
Role in the Network
  • Main speciality research areas: The team leader has trained many people in the field of archaeomagnetism, having undertaken research in this area since 1971. He has written standard textbooks on this topic, organised many international meetings and promoted and co-operated in may international projects, including the informal Network of European Archaeomagnetic laboratories.
  • Other factors: The team leader will act as Assistant Co-ordinator.
Research Linkage
  • Formal links exist with Madrid. Team links continue with Aarhus, Leoben, Sofia, Thessaloniki, Napoli, Liverpool and Bradford. Archaeomagnetic links also exist with Mexico, Egypt, Syria, Japan and other.
Senior Scientist
Prof. D.H. Tarling (e-mail: d.tarling@plymouth.ac.uk, Tel.: 0044 1752 233 102, Fax : 0044 1752 233 117)
Young researchers  
Dr. Ulf Winkler
Project
The isotope 14C is important for absolute dating methods (radiocarbon method) and is produced in the atmosphere by cosmic radiation. The production rate of 14C is not constant and varies with time. The aim is to see how changes of the geomagnetic field intensity could have influenced the 14C concentration in the atmosphere. Past 14C concentrations are well known from tree rings, and the curve shows some significant peaks. The peaks could be explained by a reduced magnetic field strength which allows more cosmic radiation (originally protons) to enter the atmosphere. This theory will be tested by the help of new archaeomagnetic data.
Recent Publications
Tarling, D.H. and C.M. Batt, Archaeomagnetic Applications for the Rescue of Cultural Heritage, Contributions to Geophysics and Geodesy (Geophysical Institute Slovak Academy of Sciences), 134, 154, 2004.

Rimi, A., Tarling, D.H. and S.O. el-Alami,  An Archaeomagnetic Study of Two Kilns at Al-Basra. In Anatomy of a Medieval Islamic Town: Al-Basra, Morocco. (Ed. N.L. Benco) BAR International Series 1234, 2004, 95-106, 2004.


Tarling, D.H., Evans, M.E., Kafafy, A.M. and A.L. Abdeldayem, Directional Archaeomagnetic Observations from Egypt. Geophysical Research Abstracts, 5, 3970, 2003.

Tarling, D.H., Kondopoulou, D., Soles, J.S. and V. Spatharas, Minoan Directional Archaeomagnetic Data from LMIB Sites at Mochlos and Kalinomouri, Crete, Geophysical Research Abstracts, 5, 3963, 2003.

Núñez, J.I., Osete, M.L., Ruiz-Martinez, V.C., Fabien, A. and D.H. Tarling, A First Secular Variation Curve for the Iberian Peninsula. Geophysical Research Abstracts, 5, 13381, 2003.

Núñez, J.I., Osete, M.L. and D. Tarling, Datación arqueomagnética del taller: El horno del sector D. El paleomagnetismo como técnica de datación arqueológica. In: Excavaciones arqueológicas en los alfares romanos de la Venta del Carmen (Los Barrios, Cádiz). Coeditado por Universidad Autónoma de Madrid y el Ayuntamiento de los Barrios (Cádiz). 307-328, 1998.

Tarling, D.H. and M. Kovacheva, Comparison of directional secular variation of the geomagnetic field between Britain and southeastern Europe, Journal of Geomagnetism and Geoelectricity, 47, 507-517, 1997.
Web-Link



Torino, Dipartimento di Scienze della Terra, Universitá degli Studi di Torino, Italy (TORI)
Role in the Network
  • Main speciality research areas: New materials in archaeomagnetic studies; geomagnetic secular variation, historical volcanism, magnetic fabrics of natural and artificial materials; magnetic prospection of archaeological sites.
  • Other factors: Access to microprobe, X-ray diffraction and TEM facilities. Very low electromagnetic noise laboratory, full equipped for magnetic measurements.
Research Linkage
  • Links with various Archaeology Departments in Italy
Senior Scientist
Prof. R. Lanza (e-mail: roberto.lanza@unito.it, Tel.:0039 11 670 5165, Fax:)
Young researcher
Evdokia Tema
Project
Archaeomagnetic data from archaeological artifacts are still very scarce in Italy and often volcanic data are used for archaeomagnetic dating. However, as the reliability of these data on tracing back the secular variation of the Earth’s magnetic field is not a posteriori proved a control of their accuracy could provide some important check points. Therefore, archaeomagnetic data from historical lava flows from Vesuvius and Etna were compared with direct measurements of the Earth’s magnetic field during last four centuries in Italy, and the results could be used to estimate the real error likely to affect the data from older lava flows, for which no direct check is possible. Nevertheless, the enrichment of the Italian  archaeomagnetic  database  could mainly be achieved by the sampling and  measurements  of  new  archaeological structures.  Up  to  now,  material  from  different   archaeological   sites (Vagnari, Ascoli Satriano, Canosa, Rome) representing various time  periods, has been sampled and measured, obtaining new directional results, while  new sampling  sites  are  always  of  great  interest.  Furthermore,  systematic measurements of the anisotropy of  magnetic  susceptibility,  anisotropy  of isothermal remanent magnetisation (IRM) and anhysteretic remanent magnetisation (ARM) are in progress in order to better understand and to estimate  the effect  of  anisotropy  on  archaeomagnetic  direction  and  subsequently  on archaeomagnetic dating.
Recent Publications
Lanza, R., Meloni, A. and E. Tema, Historical measurements of the Earth's magnetic field compared with remanence directions from lava flows in Italy over the last four centuries, Physics of the Earth and Planetary Interiors, 148, 97-107, 2005.

Lanza, R. and E. Zanella, Paleomagnetic secular variation at Vulcano (Aeolian Island) during the last 135 kyr, Earth and Planetary Science Letters, 213, 321-336, 2003.

Zanella, E., Gurioli, L., Chiari, G., Ciarallo, A., Cioni, R., De Carolis, E. and R. Lanza, Archaeomagnetic results from mural paintings and pyroclastic rocks in Pompeii and Herculaneum, Physics of the Earth and Planetary Interiors, 118, 227-240, 2000.

Chiari, G. and  R. Lanza, Remanent magnetization of mural paintings from the Bibliotheca Apostolica (Vatican, Rome), Applied Geophysics, 41, 137-143, 1999.
Web-Link


Napoli, Dipartimento di Scienze della Terra, Universitá degli Studi di Napoli, Italy (NAPO)
Role in the Network
  • Main speciality research areas: Particular interest in applications in urban geology, natural hazard assessment and cultural heritage; GSI and data management; historical lavas, statistical analysis, magnetic fabric.
  • Other factors: Considerable experience in Greek and Roman studies in southern Italy and Sicily. NAPO hosted the inaugural meeting of the informal European Archaeomagnetic Laboratory network.
Research Linkage
  • Team co-operation with Plymouth. Co-operation with Budapest and government and academic archaeological agencies
Senior Scientist
Prof. A. Incoronato (e-mail: incorona@unina.it, Tel.:, Fax:)
Young researcher
Dr. Lluís Casas
Project
Palaeodirectional and palaeointensity analysis on samples from historical lava flows from Italian volcanoes (Etna, Vesuvius, Arso) and archaeological sites (possibly involving mural paintings).
Recent Publications
La Torre, M., Livadie, C., Nardi, G. and D. Pierattini, Archaeomagnetic study of the late arcaic furnace of Treglia, Science and Technology for Cultural Heritage, 7 (2), 1998.

Chiosi, E., La Torre, M., Nardi, G. and D. Pierattini, Archaeomagnetic data from a kiln at Cassano (South Italy), Science and Technology for Cultural Heritage, 7 (2), 1998.
Web-Link


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8. Downloads

Documents about archaeomagnetism

Archaeomagnetic software

Rockmagnetic & Palaeomagnetic software


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9. Glossary

Download the glossary as  pdf-file
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10. FAQ
1. What is the Earth’s magnetic field?
2. Is the magnetic field different in different places of the Earth?
3. Does the magnetic field vary with time?
4. Does the geomagnetic field reverse soon?
5. What is the origin of the geomagnetic field?
6. What is a magnetic pole and where are they?
7. What is the magnetic equator?
8. How is the geomagnetic field recorded in baked clays?
9. Does the presence of high voltage power lines induce a parasitic remanence in archaeological baked structures?
10. Does the compass needle point towards the magnetic pole?
11. How to convert compass readings to real geographical azimuth?
12. Why to orient archaeomagnetic samples with a solar compass or a theodolite and not with a magnetic compass?
13. What is the precision of archaeomagnetic dating?
14. Did the geomagnetic field vary much during archaeological periods of time?


1. What is the Earth’s magnetic field?
The Earth acts as a giant magnet and is therefore surrounded by a magnetic field, called the Earth's magnetic field or the geomagnetic field. The geomagnetic field resembles the field of a dipole magnet (magnet with a north and south magnetic pole at its extremities) located in the centre of the Earth and inclined by 11.4° with respect to the rotation axis of the Earth. This representation is somewhat simplified as the observed field can be much more complex and varies not only in space but also in time. At any point the geomagnetic field by its direction and intensity.

2. Is the magnetic field different in different places of the Earth?
Yes. The geomagnetic field varies from place to place in an irregular way. Hence, it must be measured in many places in order to obtain an accurate image of its geographical distribution. At the moment the field is observed in about 200 operating magnetic observatories on the continents and supplemented by completed with marine surveys and with satellite measurements.

3. Does the magnetic field vary with time?
The geomagnetic field varies in time. The spectrum of variations is very large, from fractions of a second up to millions of years. There are variations of both internal and external origin. The diurnal, seasonal and annual variations are primarily of external origin and are caused by the solar activity. The sun emits particles and radiation; these are responsible for ionisations in the ionosphere with associated electrical currents and magnetic fields. The longest known cycle of external origin known is about 11 years linked to the 22 year cyclicity of the solar activity. Variations of internal origin have much greater periods from a few years to millions of years. By definition the variations of the main field of internal origin are termed secular variations. For practical reason, the secular variation is the variation from year to year. Consequently, this variation is not completely of internal origin and still contains components of external origin.

4. Does the geomagnetic field reverse soon?
Although a decrease of the geomagnetic field intensity is globally observed, one can not state that the field will reverse soon. On basis of intensity measurement since the first half of the 19th century, some researchers claim that the total dipole moment of the field will become zero in about 1300 years. But the value present day dipole moment is still much more important than it has been for most of the time during the last 50000 years and moreover the trend of decrease may switch at every moment. Even if the field would began to reverse, it appears to need several thousand years (may be 5000 to 8000) to reverse completely. The field does not become completely zero during a reversal, but it is much weaker than normal and may be multipolar. Migrating animals using the Earth’s magnetic field for orientation may be disturbed to some extent. The magnetic reversals are well-known and relatively well-dated for the last 5 million years on basis of palaeomagnetic measurements and absolute datings; the last reversal known with certainty took place 778’000 years ago. It is possible and even probable that reversals of short duration since that time.

5. What is the origin of the geomagnetic field?
The geomagnetic field finds its main origin in the liquid external core of the Earth. The most probable generally accepted hypothesis is that the geomagnetic field is generated by interaction between a magnetic field and the motion of the Earth's fluid core. This liquid is an electrical conductor and when it moves in a magnetic field (interplanetary field) electrical currents are generated that are accompanied by magnetic fields. Due to the ohmic resistance, these currents decrease in some 2000 years. Hence, there must a mechanism to regenerate the electrical currents in order to maintain the field. One of these mechanism is a self-exciting dynamo.

6. What is a magnetic pole and where are they?
The magnetic poles are defined as the points where a freely suspended magnet is vertical i.e. where the field inclination is 90°. These points are difficult to determine as the magnetic poles are not fixed but move several tens to hundreds of kilometres due to the daily variation of the field and even more during magnetic storms. Observations by the Canadian Geological Survey and the U.S. Naval Oceanographic Office place the magnetic poles at:

North magnetic pole (in 2005): 82.7° N and 114.4° W, near Elef Ringes island (Canada)
South magnetic pole (in 2001): 64.7° S and 138.0° E in the bay Commonwealth Bay (Antarctica)
Poles based on a global analysis of the observed field limiting it self to dipole terms (dipole model) are called geomagnetic poles. The geomagnetic poles that correspond to the International Geomagnetic Reference Field (IGRF) for 2005 are situated at:

North geomagnetic pole: 79.7° N and 71.8° W
 South geomagnetic pole: 79.7° S and 108.2°E


7. What is the magnetic equator?
The magnetic equator is where the inclination I, i.e. the vertical component field component V, is zero. In contrast with the geographic equator, the magnetic equator is irregular and not fixed. North of the magnetic equator the north seeking end of a freely suspended magnet dips below the local horizontal plane and I and V are counted positive. South of the equator the south seeking end of the magnet dips below the local horizontal plane and I and V are counted negative.

8. How is the geomagnetic field recorded in baked clays?
Baked clays contain magnetic minerals (mainly iron oxides) carrying the remanent magnetisation. When a sufficiently high temperature (Curie- or Néel-temperature) is reached, this remanence disappears. During cooling, below this critical temperature, a new remanent magnetisation is induced by the ambient magnetic field. This remanent magnetisation, called thermoremanent magnetisation, represents the field record during cooling.

9. Does the presence of high voltage power lines induce a parasitic remanence in archaeological baked structures?
As the electrical current flowing in these power lines is an alternating current, and the magnetic field intensity generated by this current decreases with distance, the effects of power lines on the remanent magnetisation in archaeological baked structures is generally negligible.

10. Does the compass needle point towards the magnetic pole?
The answer is no. The compass points in the direction of the local horizontal component H of the geomagnetic field and not to any single point.

11. How to convert compass readings to real geographical azimuth?
In order to convert a compass reading into real geographic azimuth, the magnetic declination of the area for the time concerned must be known. Consult local magnetic observatories or world magnetic maps edited by IAGA. The true azimuth is obtained by adding the local declination to the reading (= magnetic azimuth) following the conventions: declination in degrees W or negative, declination E or positive. When the declination is not known for the period concerned, but for another period, a correction, must be made based on the secular variation. An alternative way to find the declination is to take a compass reading in a known geographical direction (a compass reading of a long straight road or from a known point to some remarkable point that are on the map).

12. Why orient archaeomagnetic samples with a solar compass or a theodolite and not with a magnetic compass?
The geographical azimuth of a reference direction can be determined with precision on basis of the hour angle for the first and of the zenithal distance for second. It is not advised to use the magnetic compass for orienting strongly magnetic baked clays. Partially because a correction must be applied for the local magnetic declination, but mainly because errors may occur due to local magnetic anomalies (of geological origin or caused by the presence of metallic masses or electrical currents in or in the vicinity of the archaeological site).

13. What is the precision of archaeomagnetic dating?
The precision of archaeomagnetic dating depends on several factors: the fidelity of the field record in the baked clays, the absence of post-baking movements of the structure (the structure must be in-situ), the rate of change of the magnetic field and the precision of the reference diagrams, which ultimately depends on the precision of the independent dating of the baked clays on which they are based. For certain periods for the last few millennia, an average  precision of 25 years can be reached.

14. Did the geomagnetic field vary much during archaeological periods of time?
In Europe, during the two last millennia, the declination has varied in the order of about 50° and the inclination by about 20°.
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11. Links

Journals for archaeomagnetists
   Books ...
 ... with chapters on archaeomagnetism

... about sampling and orienting techniques
... about archaeology

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12. Databases
The secular variation of geomagnetic field is a regional phenomenon. Hence, secular variation master curves, which can be used for archaeomagnetic dating of burnt structures, have been developed for different countries. The increasing amount of new data in several regions of and around Europe requires a new data management. All existing and new data will be stored in an European database.

NEW
GEOMAGIA50
The GEOMAGIA50 is a database that comes with a web interface intended to give users easy access to archaeo- and palaeomagnetic intensity data. The database contains 3 700 determinations of geomagnetic field intensity for the past 50 000 years. The output is available as graphic (*.gif, *.eps) or text (ascii). A manual in pdf-form is provided, too.

Burnt structures or materials from burnt structures (sherds), which have been well-dated by non-archaeomagnetic methods, are of unpayable value for the improvement of the archaeomagnetic database. In case you know such structures or materials and which meet the sampling criteria, you are very welcome to fill the online form (sections 1, 3 and 4). We would eventually contact you for further collaboration.

Currently, local secular variation master curves are available for certain countries and their neighbouring regions. You may mail to the corresponding persons for further information and data delivery:
Country
 Contact person
 e-mail
Austria
 Robert Scholger
 scholger@unileoben.ac.at
Belgium
 Jozef Hus
 jhus@oma.be
Bulgaria
 Mary Kovacheva
 marykov@abv.bg
Denmark
 Niels Abrahamsen
 abraham@geo.au.dk
Greece
 Despina Kondopoulou
 despi@geo.auth.gr
Hungary
 Péter Márton
 martonp@ludens.elte.hu
Italy
 Roberto Lanza
Alberto Incoronato
 roberto.lanza@unito.it
incorona@unina.it
Finland
 Fabio Donadini
 fabio.donadini@helsinki.fi
France
 Philippe Lanos
 philippe.lanos@univ-rennes1.fr
Germany
 Elisabeth Schnepp
 eschnepp@foni.net
Spain
 Marisa Osete
 mlosete@fis.ucm.es
United Kingdom
 Catherine Batt
Don Tarling
John Shaw
 c.m.batt@bradford.ac.uk
d.tarling@plymouth.ac.uk
shaw@liverpool.ac.uk


On the internet you will find the global archaeomagnetic database which was compiled by Don Tarling in 1999, based on directions (declination and inclination).
http://www.ngdc.noaa.gov/seg/geomag/paleo.shtml

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13. Funding opportunities through the European Union

General funding
The persistent development of intellectual property is one of the foundations of our society. This is recognised by the European Union, which endeavours to support scientific research and technological development through a multiplicity of funding instruments. Recently, the Framework programme 7 (FP 7), covering the period from 2007 to 2013, has been published and is now under the co-decision procedure for approval and adoption by the European Parliament and Council.

The research is organised in nine sub-programmes:

    * Health
    * Food, agriculture and biotechnology
    * Information and communication technologies
    * Nanosciences, nanotechnologies, materials and new production technologies
    * Energy
    * Environment (including climate change)
    * Transport (including aeronautics)
    * Socio-economic sciences and the humanities
    * Security and Space

For further information and the timeline of FP7 follow the links below:

http://www.cordis.lu/fp7/home.html
http://www.cordis.lu/fp7/roadmap.htm

Marie Curie actions

Below some fellowships of the Marie Curie human resources and mobility programme are described. For detailed information please see at:  http://www.cordis.lu/mariecurie-actions/home.html


    Early stage research training
    Transfer of knowledge
   
     Intra-European fellowships
      Reintegration grants
    FAQ about Marie Curie actions
        http://europa.eu.int/comm/research/fp6/mariecurie-actions/information/faq_en.html

last updated 30. 05. 2006 ss
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