Chemistry and microscopy of atmospheric particulates at Delos (Cyclades-Greece)

In order to explain the weathering mechanisms of marbles and granites used in the monuments of Delos archaeological site (Cyclades-Greece), research has characterized atmospheric particles and defined stones petrophysical properties. In this paper, characteristics of atmospheric particulates are presented: from:sampling in March and July 1995. Air was filtered through Nuclepore membranes and particles were analysed by X-Ray Fluorescence (XRF), Analytical Scanning Electron Microscopy (ASEM) and Analytical Transmission Electron Microscopy (ATEM). XRF measurements show that Na, Cl and S have the highest concentrations. According to geochemical calculations, it appears that S is constituted in major part by excess S, anthropic in origin. Individual analyses by:ASEM allow the classification of particles greater than or equal to 1 mu m in:five categories: marine, terrigenous, mixture of marines and terrigenous and undetermined species, anthropogenic and biogenic. ATEM study concerned S-bearing fine particles (less than or equal to 2 mu m). Two atmospheric sources able to participate in marbles and granites weathering have been identified: a natural source of marine salts (halite mainly) the production of which depends on wind speed; an anthropic source (high excess sulphur concentrations) which indicates a regional to remote pollution. (C) 1999 Elsevier Science Ltd. All rights reserved.