465 14TH SINKHOLE CONFERENCE NCKRI SYMPOSIUM 5 EVAPORITE GEO-HAZARD IN THE SAURIS AREA (FRIULI VENEZIA GIULIA REGION - NORTHEAST ITALY) Chiara Calligaris Dipartimento di Matematica e Geoscienze, Università degli Studi di Trieste, Via Weiss, 2, Trieste, 34128, Italy, calligar@units.it Stefano Devoto Dipartimento di Matematica e Geoscienze, Università degli Studi di Trieste, Via Weiss, 2, Trieste, 34128, Italy, sdevoto@units.it Luca Zini Dipartimento di Matematica e Geoscienze, Università degli Studi di Trieste, Via Weiss, 2, Trieste, 34128, Italy, zini@units.it Franco Cucchi Dipartimento di Matematica e Geoscienze, Università degli Studi di Trieste, Via Weiss, 2, Trieste, 34128, Italy, cucchi@units.it Survey of Friuli Venezia Giulia Region. The objective of this project is to inventory and classify the sinkholes associated to evaporite rocks. Introduction Subsidence phenomena associated to the presence of evaporite rocks are common in Europe. Evaporite sinkholes affect the central and northern part of England (Cooper, 2008), Lithuania (Taminskas and Marcinkevicius, 2002), NE Spain (Gutiérrez, 1996; Gutiérrez and Cooper, 2002; Guerrero et al., 2004; Gutiérrez et al., 2008) and Albania (Parise et al., 2004; Parise et al., 2008). As reported by Nisio (2008) and by Caramanna et al. (2008), sinkholes occur also in Italy where are distributed along the whole peninsula, especially in some regions, such as Sicily, Lazio, Campania, Alto Adige, Puglia, and Friuli Venezia Giulia. The Friuli Venezia Giulia Region is located in the NE part of Italy and covers an area of 7,858 km 2 . Here are present 221 municipalities of which approximately 40 coexist with geo-hazard problems associated to the existence of outcropping or mantled karstifiable rocks. Limestones and dolostones represent approximately 24% of the whole regional territory, whereas evaporite rocks do not exceed 1% (Figure 1). In all those areas, where evaporites and limestones outcrop or are mantled by quaternary deposits or other rock types, sinkholes Abstract Evaporite sinkholes represent a severe threat to many European countries, including Italy. Among the Italian regions, of the area most affected is the northern sector of Friuli Venezia Giulia Region (NE Italy). Here chalks had two main depositional periods first in the Late Permian and then during the Late Carnian (Late Triassic). Evaporites outcrop mainly in the Alpine valleys or are partially mantled by Quaternary deposits, as occur along the Tagliamento River Valley. Furthermore, evaporites make up some portions of mountains and Alpine slopes, generating hundreds of karst depressions. This paper presents the preliminary results of the research activities carried out in Sauris Municipality where sinkhole phenomena related to the presence of gypsum are very common. Field investigations were devoted to recognition, mapping and classification of evaporite sinkholes. To recognize sinkhole phenomena, the preliminary steps included the analysis of historical documents collected in archives, the analysis of aerial photos and Airborne Laser Scanning (ALS) surveys. The integration of the above- cited activities allowed a preliminary identification of the phenomena, which were later validated by detailed field surveys. All the collected data populate a geo-database implemented for a project funded by the Geological