Problematyka konserwatorska Kolosów z Wyspy Wielkanocnej

• Authors: Domasłowski Wiesław

Title variants

EN

PROBLEMS OF THE CONSERVATION OF THE COLOSSUSES FROM THE EASTER ISLAND

• Languages of publication: PL EN

Abstracts

EN

The Easter Island, an islet (180 m2) situated on the Pacific, has become a point of interest already since its discovery by Jacob Roggeven in 1722. This interest should in the first place be ascribed to stone sculptures which are there and which strike with their forms and dimensions. Original sculptures (known as moai) stood on stone platforms (the so-called ahu - photo 1) but due to some unexplained reasons they got thrown down (photo 2). At present there are over 600 moai sculptures on the Easter Island (called Rapa Nui by the natives). Part of them (28) have been placed anew on ahu (photos 3, 4, 5), others rest on them or in their vicinity, while some of them are on the roads leading from quarries (photo 6) or (the biggest number) in a quarry which had been an extinct volcano of Rano Ravahu (photos 7, 8). The condition of the sculptures gave rise to concern and therefore upon the recommendation of UNESCO studies were made on them by G. Hyvert in 1972 and by the author of this article in 1981. This article presents an outline of the report passed on to UNESCO in 1982. The report gave a description of the condition of the sculptures (photos 9, 10, 11) and explained reasons for the decay of the stones. It also put forward proposals for conservation. In order to define causes of the decay studies have been made on a degree of the tightening of the stones (photo 13), ability to lift up water and organic fluids, humidity, dampness of sculptures, temperature of their surface, composition and texture of stratifications, kind of microflora as well as the quantity and kind of soluble salts in water contained in stones and in soil. The stratification was determined on the basis of the examination of grindings of stone samples under a stereoscope microscope (photo 14), examination of scraps in a scanning microscope (photos 15 and 16) as well as on the basis of a spectrophotometric infrared analyses, photocolorimetry and diffractional X-ray analysis. On the basis of the studies made it has been found out that the main factors destroying the sculptures include rain water, changes of temperature, microorganisms and, in some cases, water-soluble salts. The action of the above-mentioned factors is enhanced by a mineralogie composition, structure and texture of the rock of which the sculptures were made (volcanic andesite tuff, in which, apart from proper rock components such as glaze, plagioclases, angite, peridotite and allophane there also appear basalt scraps of a different size). It has been assumed that silt components are removed by rain, which brings about the loosenning of the cohesion of surface layers. Rain water is also a factor enabling the formation of tight and hard deposits on the surface of sculptures, whose main component is silica in form of opal. This silica is formed due to decomposition of aluminosilicates and it is possible that microorganisms parasitizing om the surface of sculptures participate in this process (photo 12). The following species have been distinguished: the algae (Cyanophyceae), leafy lichens (close to Phizocarpon species). The algae and leafy lichens affect the stones very strongly — the surface in which they are is markedly impaired in a 1 mm layer. In working out a programme of conservation work attention has been paid to the causes of stones’ decay. The main emphasis has been put on the protection of sculptures against the effect of water, which will make it possible to restrain a decomposition of stone components, prevent the development of microorganisms and curtail a destructive action of the salt. Techniques of consolidating the impaired parts of the stones, removal of deposits and microorganisms as well as cementing the stones and making up the missing parts have been discussed as well. In conclusion it has been stated that conservation works on sculptures should be undertaken as soon as possible, as every year of delay brings about irretrievable loss leading to the transformation of statues into a shapeless block of stones. It has also been proposed that the works should be carried out by outstanding conservators under the auspices of UNESCO.

• Publisher: Narodowy Instytut Dziedzictwa
• Journal: Ochrona Zabytków
• Year: 1985
• Issue: 2
• Pages: 86-98

Dates

published

1985

Contributors

author

Domasłowski Wiesław

• prof. dr hab., Instytut Zabytkoznawstwa i Konsennratorstwa UMK w Toruniu

References

• G. Hy v e r t , Les statues de Rapa Nui, „Conservation et restauration” , UNESCO, Nr de serie: 2868/RDMO.RD/CLP, Paris, mars 1973.
• W. D o m a s ł o w s k i , A. Mł y ń s k i , R. M i r o w s k i , D. S o b k o w i a k , H. G a ł k o w s k i , W. Ma j e w s k i , Badania nad technologią zapraw cementowych przeznaczonych do uzupełniania obiektow zabytkowych, „Studia i Materiały", PKZ, 1977, s. 1.

Identifiers

ISSN

0029-8247