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| Titel |
Chemical analysis of black crust on the Angkor sandstone at the Bayon temple, Cambodia |
| VerfasserIn |
Wonsuh Song, Chiaki Oguchi, Tetsuya Waragai |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250096595
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| Publikation (Nr.) |
 EGU/EGU2014-12105.pdf |
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| Zusammenfassung |
| The Angkor complex is the one of the greatest cultural heritages in the world. It is
constructed in the early 12th century, designated as a world cultural heritage by UNESCO in
1992. The temples at the Angkor complex are mainly made of sandstone and laterite.
However, due to the tropical climate, plants, lichens and various microorganisms are growing
well on the rock surface. Black crusts are also easily found on the stone surface.
The 21st technical session of the International Coordinating Committee for the
Safeguarding and Development of the Historic Site of Angkor (ICC-Angkor) held in
2012 recommended that to preserve both the biofilms and the forest cover and to
prohibit the biocides (chlorine-based) and organic biocides. However, there are
many reports that lichens and microorganisms accelerate rock weathering. It is
important to clarify that how the biofilm on the Angkor temples affect Angkor
sandstones.
We sampled Angkor sandstone covered by black crust at the Bayon temple, Angkor
complex, and observed the section and the surface of the rock sample by using SEM.
Surfaces of the samples are not polished in order to observe the original condition. The
samples are coated with gold for 180 seconds. The depth of the black crust is up to 1 mm.
Many filamentous materials were found on the black crust. Average energy-dispersive X-ray
spectroscopy data of the five areas of ca. 20 μm x15 μm in the black crusts shows that
over 80 % of the filamentous materials are compounds of carbon. It seems that
these materials are hyphae. The shape of the hypha is like a thread and its size
is few μm in diameter and up to several centimeters in length. Black crusts are
consisted of elements and compounds of carbon, Na, Mg, Al, Si, Cl, K, Ca, and
Fe.
Further research has to be done to find out the better and proper way of conservation for
the Angkor complex. |
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