Russian Scientific Resarch Institute for Cultural and Natural Heritage named after D.S. Likhachev, Moscow
ARCHAEOLOGICAL HERITAGE: SPECIFICS OF PRESERVATION, STUDY AND USE UNDER THE PERMAFROST CONDITIONS
A most important factor contributing, on the one hand, to the specifics of the cultural levels study in the Arctic, and on the other, demanding the development of special techniques for its study and preservation on the not yet excavated/in the process of excavation parts of the site is the presence of permafrost (or frozen ground). Permafrost is not universally present in the Arctic zone: it is not very common in the western part of the Russian Arctic (the Kola peninsula) because of Gulf Stream effect. Permafrost processes were also not typical for the sandy hills on which most of the camps were made by the ancient population of the Pechora polar region. Frozen ground levels were universally present in the sites of the lower Ob and in the Yamal and the Gydan peninsulas. Frozen levels were also characteristic for the sites of the East-Siberian Arctic. This paper presents an overview of some approaches to field work organization under the conditions of the presence of cultural levels in permafrost, and certain preliminary conservation of the finds techniques.
Frozen ground formed in the cultural levels as a result of their growth in the process of human economic activity. This is not "permafrost" in a geological sense, but rather the product of human activity. In the summer the cultural level thaws to the depth of 40-60 centimeters from the surface.
Daily natural thawing amounts to 8-10 cm, this level should be removed daily following the general methodology until it became a mush. It is advisable to start the excavation on a surface with a small slope. That would provide for the natural drainage of part of the area. In the process of going deeper it is necessary to organize trenches of 0.5 m wide in the lower part of the excavation for drainage purposes.
Test pits' area must be at least 2x2 m, since one meter pits would thaw unevenly and, at approximately 1 meter depth, would taper off with the daily thawing rate of 2-3 cm.
As a rule the cultural levels in frozen ground are rich in organic items: bone, wood, leather, whalebone, grass, mammoth and walrus ivory. No heating or "ramming" equipment may be used on the level, because this would damage or even destroy the organic items. Modern chemicals (primarily polyoxyethylene glycol) are widely used for the preservation of organic items and their conservation in field conditions and further transportation to the restoration shops. Many artifacts associated with religious ceremonies or illustrating some mythological performances were created from organic materials and could be extracted and preserved only owing to the availability of modern field conservation and restoration techniques. This resulted in a sharp increase of our knowledge about the religious life of the Arctic population in antiquity and during the pre-industrial age.
In case the excavations are planned to be continued in the following season it is necessary to cover the excavated area with film, then place wooden planks on top and press them with a tightening weight. One of the reasons for that is protection from wild animals who could destroy the cultural level often containing fragments of sublimated meat attracting the animals.
Without following these, in fact quite simple, rules we risk an irrecoverable loss of a significant part of the archaeological heritage of the Arctic.