0000000000479325
AUTHOR
Al Gagliano
Geothermal mercury output at Nisyros Volcano (Greece)
Nisyros (Greece) is an active volcano in the eastern part of the South Aegean Active Volcanic Arc (SAAVA), hosting a high-enthalpy geothermal system. On June 2013, an extensive survey on Hg concentrations in different types of matrices (fumarolic fluids, atmosphere, soils and plants) was carried out at Lakki plain, an area affected by widespread soil degassing and fumarolic manifestations. To investigate the spatial distribution of mercury emission and its possible relationships with diffuse degassing of hydrothermal fluids, Hg concentrations in soils were related to their physicochemical parameters (e.g. temperature, soil-pH, hydrothermal gases and elemental C, N and S concentrations). Fur…
Duvalo (North Macedonia): A "volcano" without volcanic activity
T he Duvalo locality is located in the SW of the Republic of North Macedonia, in the Ohrid region, near the village of Kosel. It is an area of strong soil degassing, called “volcano” by the local people despite volcanic activity has never been documented in the recent geologic history of the area [1]. A large area (thousands of sqm) shows signs of strong alteration and is devoid of vegetation. Until the 19thcentury sulphur was mined from this area [1]. In August 2019, a campaign of soil CO2 flux measurements and soil gas sampling was made. Duvalo is sometimes referred to as an active geothermal feature but no signs of enhanced geothermal gradient were found and the soil temperatures at 50 c…
Gas Geochemistry and Fractionation Processes in Florina Basin, Greece
Florina Basin is located in northern Greece, close to Mount Voras where the volcanic activity of Late Messinian age began. In the area, many CO2-rich gas emissions are present as a bubbling free-phase in groundwater (both springs and wells) and soil gases. Volcanism along with the geological and geodynamic regime of the basin, created the ideal conditions for CO2 accumulation in vertically stacked reservoirs. One of these, industrially exploited by the company Air Liquide Greece, produces 30,000 t/a of CO2. Results show that CO2 concentrations in the gases of Florina can arrive up to 99.8% and are mostly above 90%. Moreover, C-isotope composition (-2.1 to + 0.3 h vs. VPDB) indicates a mixed…