ORIGIN AND GROWTH OF WEATHERING CRUSTS ON ANCIENT MARBLES IN INDUSTRIAL ATMOSPHERE

The origin and growth of weathering crusts on the ancient marbles of r uins of the Sanctuary of Demeter in the industrial atmosphere of Eleus is in Greece have been investigated. A systematic mineralogical, petro graphical and chemical examination of weathered stones and crusts was performed, both in situ and in the lab, on samples taken from differen t parts of the monument in relation to the surface characteristics as well as to the exposure to rain, sea-salt spray and wet and dry deposi tion of airborne pollutants and dust. In particular, the various mater ial-environment interactions take place, are characterized by (a) disi ntegrated ''washed-out'' surfaces, where products are taken away throu gh dissolution, (b) rusty yellow patinas rich in Fe and Cu, (c) firmly attached black crusts in contact with percolating water, where recrys tallized calcite shields amorphous deposits rich in S, Si, Fe and carb onaceous particles, (d) black loose deposits in the water sheltered ar eas, consisting mainly of gypsum and fly ash particles and (e) cementi tious crusts, coating and pitting the horizontal surfaces. Moreover, a n interconnected evolution of various physicochemical processes is sho wn, characteristic of the origin and growth of various crusts, which a re formed and classified accordingly. (C) 1998 Elsevier Science Ltd. A ll rights reserved.