Mapping the shafts of Laurion – Contribution to a new geological stratigraphy

The mining territory of Laurion in Attica-Greece comprises a great number of shafts constructed since antiquity in order to exploit the silver bearing ore deposits. These vertical constructions have presumably served a multipurpose role as artificial conduits for uplifting the extracted material, exploration shafts as well as ventilation chimneys. They are situated in an area of 70 km2 and their depth varies from a few meters to over 100 m. The different contacts of the Laurion rock sequences, where the ore mineralization was deposited, are visible in the majority of the shafts. The main extracted minerals found in the primary and oxidized carbonate replacement deposits are galena, cerussite and anglesite. The ore mineralization is hosted in mantos and chimneys clearly visible in the shaft's interior. This study presents the results of the “Laurion Shafts Project” that took place during 2018 with its primary objective the description of the stratigraphy in selected mining shafts at Laurion. During the research, 284 mining shafts were located, and 10 of them were speleologically explored and topographically mapped with the use of the laser meter Disto-X2. Geological mapping was also performed at the inner part of the selected shafts. The gained stratigraphic data provide enough information for a general stratigraphic column and will contribute to the future construction of a 3D geological model of the Laurion mining district.