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In this context, archaeological prospecting can be defined as searching for and mapping concealed and partially concealed prehistoric remains using various scientific methods and equipment. Geophysical instruments are particularly important here, gradiometers, georadar and electrical resistivity meters being especially widely used.
Such non-destructive methods have gained relatively little foothold among Scandinavian archaeologists, who mostly favour mechanical topsoil stripping, probing and trial trenching when they need to determine whether a piece of land conceals prehistoric remains. This contrasts greatly with the situation in many other countries, notably the British Isles, where most of the methodology and instrumentation were developed. One reason for the limited interest for these methods among many Scandinavian archaeologists may be the view that the bedrock and soil here are mostly unfavourable for such methods. Indeed, as regards magnetometry it is not unreasonable to think that the bedrock and soil in large parts of Scandinavia are so rich in magnetic minerals as to be an obstacle to the application of magnetic methods to seek prehistoric remains. This magnetic ‘noise’ would simply drown any signals from prehistory. However, concentrations of relatively magnetic stones have actually proved to have a positive effect, revealing prehistoric remains.
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This kind of geophysical archaeological prospecting has several advantages compared with methods commonly applied in Scandinavia when the archaeological potential of an area is to be assessed. These advantages include:
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Under favourable conditions, with good magnetic contrast (positive or negative anomalies) between archaeological features and their immediate surroundings, it is possible to recognise structures (remains of buildings, hearths, pits, graves, etc.). Sometimes, a firm interpretation can be made, or simple probing will confirm a suspected feature. In doubtful cases, it may be necessary to dig a trial pit or trench, but you will have specific evidence indicating where it is most advantageous to dig.
Such archaeological prospecting is especially favourable
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Mapping with a fluxgate gradiometer
Backed up by long experience from geological and archaeological field mapping in Norway, RB GeoArk has for many years been carrying out magnetometric investigations of prehistoric and potential prehistoric sites on behalf of archaeologists and others. Some 70 areas at more than 40 sites from Tromsø and Laksefjord in the north to Stavanger in the southwest of Norway, and also on the Faeroes, have so far been investigated.
The equipment used for this mapping is a gradiometer, an advanced form of magnetometer specially developed for rapid archaeological prospecting. This geophysical instrument registers small variations in the magnetic signals emanating from the ground. These signals are processed by a computer program and printed out as maps.
| What can a gradiometer reveal?
In principle, a gradiometer can reveal anything that produces a magnetic contrast (an anomaly) relative to its immediate surroundings. Due to variable bedrock, superficial deposits and soils, this will vary somewhat from place to place and country to country. Although a fairly rough survey may reveal large postholes, closely spaced measurements are generally necessary to recognise patterns that can reasonably definitely identify buildings constructed with posts. Sometimes buildings can be recognised by linear anomalies produced by beam slots or external drainage ditches, and regularly arranged midline hearths, phosphate-rich and/or trampled earth floors, stone floors and corner stones (pad stones) may also offer good magnetic contrast. Buildings constructed solely of timber or turf are difficult to identify directly. |
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Examples of areas that have been mapped in Norway
The firm is run by geologist Richard Binns and archaeologist Kari Støren Binns. In addition to gradiometer surveys, RB GeoArk also undertakes other geo-archaeological and geological investigations, including studies at rock-art sites, bedrock mapping and petrographic studies, as well as mapping of cultural heritage sites, archaeological information services (signs, brochures, booklets, etc.), drawings and watercolours with archaeological, historical or landscape associations, and test excavations (subject to prior permission).
RB GeoArk personnel have long, and countrywide, experience of seeking, recording and describing prehistoric sites for the regional museums in Norway, partly in connection with the production of land-use maps for the Norwegian Mapping Authority. Link: https://askeladden.ra.no
Presenting archaeology for a wider public
RB GeoArk personnel have carried out many assignments in connection with the presentation of cultural heritage sites and archaeological discoveries, chiefly in central Norway. These have included editing a bi-annual magazine, writing chapters in books on local history, preparing texts and illustrations for information signs, booklets and pamphlets, and acting as guides on excursions.
SPOR, a magazine published at the Department of Archaeology and Cultural History, Museum of Archaeology and Natural History, Trondheim http://www.ntnu.no/vitenskapsmuseet/les-spor-her
Local history:
Helgeland historie, vol. 1 (1985)
Leirfjord bygdebok, vol. 1 (1985)
Fosen historie, Chap. 2 (2005)
Fotefar mot nord, no. 17: Facing the Forces (24 pages describing sites near Brønnøysund, Nordland) http://fotefar.no/Filnedlasting.aspx?MId1=3354&FilId=1510
Guide to 10 selected cultural heritage sites in Steinkjer, central Norway (32 pp.) http://content.yudu.com/Library/A1nnve/Veivisertil10utvalgt/resources/13.htm
Various information signs and exhibitions in central and northern Norway
Illustrations of archaeological and historical sites and events
In connection with the above, many watercolours and drawings have been made to illustrate situations from prehistory and historical time for publications, TV programmes and signs.
Examples
 Stone Age settlement near Kristiansund |
 Burial ground at Helge, Steinkjer - illustration for a sign
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Kjøpmannsgata, a street in Trondheim about 1250 AD
- book illustration
RB GeoArk has personnel with many years’ experience throughout Norway of participating in and managing archaeological excavations, mainly on behalf of the regional museums. When prior permission has been obtained, we can undertake such excavations on our own behalf or for clients. Such an excavation is ongoing at Klæbu, central Norway, in connection with the longhouse presented elsewhere on this web site.
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