107-115

Articles

• García Giménez, R.
• de Soto, Isabel S.
• Caballero Arribas, J.
• Vigil de la Villa Mencia, R.

Granitic rock presenting varying alteration processes were sampled from three of five tombs unearthed in Αvila (Spain). The origin of these processes could be both biogenetic and climatic. The purpose of this study is to examine the alteration processes in granitic rocks from the tombs in the area around the Church of San Andrιs (Αvila) and to compare these archaeological materials with similar raw materials that could have been employed in their construction. Samples of granitic rock used in the constructive elements of tombs were collected from the same location to compare their physicochemical properties with granite from local quarries. The physical properties of the samples were studied by Polarisation Microscopy and their porosity was determined by BET methodology. Their major and minor constituents were analysed by ICP-MS and their most relevant crystalline mineral compounds (quartz, opal, plagioclase, potassic feldspars, phyllosilicates and hematite) were quantified using X-Ray Diffraction Spectrometry

• History and Archaeology

• Αρχαιολογία

granitic rock, porosimetry, petrography analysis, alteration, weathering, Spain

Corresponding author: García Giménez (rosario.garcia@uam.es)

1. Adamo, P., Marchetiello, A., Violante, P., (1993), The weathering of mafic rocks by lichens, Lichenologist, 25(3): 285-297.Ariño, X. and Saiz-Jimenez, C., (1996), Factors affecting the colonization and distribution of cyanobactera, algae and lichens in ancient mortars, in: J. Riederer J (ed.), Proceedings of the eighth international Congress on Deterioration and Conservation of Stone, vol. 2, Rathgen-Forschungslabor, Berlin, Germany, pp. 724-731.Ascaso, C., (1985), Structural aspects of lichens invading their substrata, in: C. Vicente, D.H. Brown, E. Legaz (Eds.) Surface Physiology of Lichens, Universidad Complutense. Madrid, Spain, pp. 87-113.Beig, M.S. and Lüttge, A., (2006), Albite dissolution kinetics as a function of distance from equilibrium: Implications for natural feldspar weathering, Geochimica and Cosmochima Acta, 70, 1402-1420.Berger, G., Beaufort, D., Lacharpagne, J.L., (2002), Experimental dissolution of sanidine under hydrothermal conditions: mechanism and rate, American Journal Science, 302:663-685.Bjorkum, P.A., Mjos, R., Walderhaug, O., Hurst, A., (1990), The role of the alteration Cimmerian uncorformity for the distribution of kaolinite in the Gullkaks Field, northern North Sea, Sedimentology, 7, 395-406.Brunauer, S., Emmet, P.H., Teller, E., (1938), Adsorption of gases inmultimolecular layers, Journal of the American Chemical Society, 60 (2), 309-319.Bustillo, M.A., (1995), Una nueva ultraestructura de ópalo CT en silcretas. Posible indicador de una influencia bacteriana, estudios Geológicos, 51, 3-8.Caballero Arribas, J., (1996), La plaza de San Vicente de Ávila: necrópolis parroquial y nivel romano, Numantia, 6:128-132.Casey, W.H. and Ludwig, C. (1995), Silicate mineral dissolution as a ligand-exchange reaction, in: A.F. White, S.L. Brantley (eds.), Chemical weathering rates of silicate minerals, Min. Soc. Am., Washington, USA 31, pp. 87-118.Churchman, G.J. and Gilkes, R.J., (1989), Recognition of intermediates in the possible transformation of halloysite to kaolinite in weathering profiles, Clay Minerals, 24:579-590.Del Monte, M., Rattazi, A., Romao, P.M.S., Rossi, P., (1996). The role of lichens in the weathering of granitic buildings, in: M.A. Vicente , J. Delgado Rodrigues, J. Acevedo (Eds.) Proceedings of Workshop on Degradation and Conservation of Granitic Rocks, Santiago de Compostela, Spain, pp. 301-306.Edwards, H.G.M. and Seaward, M.R.D., (1995), FT-Raman spectroscopic studies of lichen–substratum interfaces in biodeterioration studies, Biodeterioration and Biodegradation, 9:199-203.García Talegón, J., Vicente, M.A., Molina-Ballesteros, E., Vicente-Tavera, S., (1999), Determination of the origin and evolution of building stones as a function of their chemical composition using the inertia criterion based on an HJ-biplot, Chemical Geology, 153: 37-51.Gehrmann, C. and Krumbein, W.E., (1994), Interactions between epilithic and endolithic lichens and carbonate rocks, in: V. Fassina, H. Ott, F. Zezza (Eds.) Proceedings of the 3er international Symposium The Conservation of Monuments in the Mediterranean Basin. Venecia, pp. 311-316.Govindaraju, K., (1994), Compilation of working values and samples description for 383 geostandards, Geostandards Newsletter special issue. Vandoeuvre, Lès Nancy, France, vol. XVIII, 158 pp.Mansch, R, Bock, E., (1993), Untersuchung der Beständigkeit von keramischen, Werkstoffe Korrosion, 45:96-104.Oelkers, E.H. and Schott, J., (1999), Experimental study of kyanite dissolution rates as a function of chemical affinity and solution composition, Geochimica and Cosmochimica Acta, 63 (6):785-797.Prieto, B. and Silva, B., (2005), Estimation of the potential bioreceptivity of granitic rocks from their intrinsic properties, international Biodeterioration and Biodegradation, 56:206-215.Silva, B., Prieto, B., Rivas, T., Sánchez Biezma, M.J., Paz, G., Carballal, R., (1997), Rapid biological colonization of a granitic building by lichens, international Biodeterioration and Biodegradation, 40:263-267.Taylor, A.S., Blum, J.D., Lasaga, A., (2000), The dependence of labradorite dissolution and Sr isotope release rates on solution saturation state, Geochimica and Cosmochimica Acta, 64: 2389-2400.Vigil de la Villa, R,, García, R., Rubio, V., Ballesta, R.J., (2000), Soil alteration processes on granite in the Central Mountain Range (Spain), Z. Geomorphology, 44(2): 233-248.Wierzchos, J. and Ascaso, C., (1998), Mineralogical transformation of bioweathered granitic biotite, studied by HRTEM evidence for a new pathway in lichen activity, Clays and Clay Mineralogist, 46(4): 446-452.Zouridakis, N. and Tzevelekos, K., (1999). Nitrogen porosimetry on ancient ceramics, Journal european Ceramic Society, 19:89-92.