COLORED MINERAL COATINGS ON MONUMENT SURFACES AS A RESULT OF BIOMINERALIZATION - THE CASE OF THE TARRAGONA CATHEDRAL (CATALONIA)

Authors
GARCIAVALLES M VENDRELLSAZ M KRUMBEIN WE URZI C
Citation
M. Garciavalles et al., COLORED MINERAL COATINGS ON MONUMENT SURFACES AS A RESULT OF BIOMINERALIZATION - THE CASE OF THE TARRAGONA CATHEDRAL (CATALONIA), Applied geochemistry, 12(3), 1997, pp. 255-266
Citations number
47
Categorie Soggetti
Geochemitry & Geophysics
Journal title
Applied geochemistry → ACNP
ISSN journal
08832927
Volume
12
Issue
3
Year of publication
1997
Pages
255 - 266
Database
ISI
SICI code
0883-2927(1997)12:3<255:CMCOMS>2.0.ZU;2-A
Abstract
Successive coloured coatings on the Taragona cathedral (Catalonia) wer e analyzed using chemical, microbiological and mineralogical technique s. The coatings consist of mainly biogenic minerals (calcite, several oxalates, phosphates) and their fabric and composition is independent of the underlying rock. The origin of the crusts or patinas is attribu ted to bygone (sub-fossil) microflores which formed biofilms and micro bial mats on and within the surface of the limestones and marbles of t he cathedral. The staining of the patina layers is not related to the mineral colours, nor to anthropogenic dust or fly-ashes. The colours a re most probably organic pigments embedded between the crystals and Fe - and Mn-organic compounds remaining from bioactivity. A sequential hy pothesis of the origin(s) of the patina layers is given. (C) 1997 Else vier Science Ltd.