『Abstract
For a long time the local Ordovician carbonate rocks were widely
used for the building of many historical buildings, churches and
strongholds in Tallinn. The chemical and mineralogical composition
of building stone and gypsum black crust from five historical
objects of Old Town of Tallinn were examined in order to reveal
the weathering behaviour of the limestone and estimate the influence
of pollution on the decay processes. The ICP-MS analysis and X-ray
diffractometry were performed to provide a quantitative analysis
of the processes, which are responsible for building stone decay.
The enrichment factor and R-mode factor analyses were applied
in order to improve the understanding the nature and source of
elements and assess the pollution effect. The obtained results
confirmed a natural origin for Ca, Mg, Si, Al, Ti, K, Na and Fe.
The black crust is elevated in Cu, Pb, Sb, Sn and Zn concentrations
as a result of the pollution effect. The highest increase of Cu,
Pb and Zn content was determined in the samples from gypsum crust
at St. Olaf's church. The enrichment factors calculation and factor
analysis confirm the input of these elements from anthropic sources.
Sulphur isotope composition in damaged building stone and black
crust was used to discriminate the anthropic and natural sources
of sulphur. The impact of technogenous sulphur in the gypsum formation
in the black crust was revealed. The contribution of sulphur dissoluted
from limestone is reflected in the positive delta values of sulphur.
Comparison of obtained data to those for similar objects in European
cities was carried out.
Keywords: airborne pollution: black crust; chemical and mineralogical
composition; limestone; sulphur isotope 』
1. Introduction
1.1. Geographical pattern and air quality in Tallinn
1.2. Atmospheric pollution and stone decay
1.3. Descriptions of carbonate building stones in Tallinn
2. Sampling and analysis
3. Results and discussion
3.1. Damaged building stone
3.2. Black crust
3.3. Trace elements in the black crust
3.4. Enrichment and factor analyses
3.4.1. Enrichment analysis
3.4.2. Factor analysis
3.5. Isotope composition of sulphur
4. Conclusions
Acknowledgements
References