An investigation of the anthropogenic impacts on the surface of the stone-built heritage in Venice: the well-heads as case studies

Abstract

The concept of the Anthropocene was coined by Crutzen and Stoermer in 2000, which refers to the Earth’s most recent geological time period as being human-influenced or anthropogenic. Regarding the impact of anthropogenic activities on the built heritage, several studies show the potentiality of architectural stone as a recorder and asset of past human-induced actions evolution and trend to read. This thesis aims to visually and qualitatively investigate architectural stone degradation due to direct and indirect anthropogenic impacts in Venice. The case study chosen for this research is the surface of a stone-built architectural element, so-called “vera da pozzo” (well-head), which the wells were in operation until the early 20 century for at least four centuries, and Istrian stone and Verona marble were mainly used as the head construction materials. This thesis is structured as follows: 1- The introduction tries to briefly explain the history and function of the wells and well-heads in Venice and the materials the heads are built of. Moreover, according to the literature, possible anthropogenic causes and stone weathering types for this research are defined. 2- The experimental methods for this thesis are divided into visual and qualitative analyses. The visual research is carried out with the help of a private photo archive created by Giuseppe Pasqucci and an on-site photo collection to visually compare the current and past state of conservation of the selected well-heads, according to determined parameters reported in the ICOMOS glossary and in “The Fragile Venice” study publication. In addition, on-site (Raman spectroscopy, digital optical microscopy) and laboratory analyses ( FTIR spectroscopic analyses ) are conducted to investigate the chemical composition of the degraded surfaces whether there is an anthropogenic cause. 3- The results obtained from the photo comparison are shown and qualitatively evaluated in order to find any possible correlations concerning the past and the actual state of conservation of the chosen well-heads. Furthermore, the analytical results are illustrated, and the nature of trends is discussed. 4- The conclusion briefly explains the findings of this thesis and possibly recommends for the future studies.