Geochemical Investigations Of Submarine Volcanic Exhalations To The East Of Panarea, Aeolian Islands, Italy
Journal Article: Geochemical Investigations Of Submarine Volcanic Exhalations To The East Of Panarea, Aeolian Islands, Italy
AbstractResults are presented on scubadiving investigations carried out on thermal manifestations in the area of Panarea (Aeolian Islands). The area investigated falls inside a caldera which extends from the main island to the group of islets located to the northeast. The distribution of the gaseous manifestations is regulated by the NE-SW, NW-SE and N-S regional tectonic directrices, through which the more recent basic magma intruded, giving rise to dikes and pillow lavas. fO2-temperature relation of the gases sampled in the investigated area was calculated to be: logfO2 = 11-24,593/T which indicates that a buffering mechanism acted on the gases as they cooled down during their ascent. The high 3He/4He ratio (6 _ 10-6) and the Δ13C = -3.2%. (PDB), suggest the presence of a magmatic component in the gas feeding the investigated manifestations. The above relations and the almost constant high He/N2 ratio suggest that all the fumaroles are fed by the same deep hot fluids. On the basis of both the chemical characters of the fluids and the geothermo-barometric data, a deep geothermal body, having a temperature of about 240°C, is recognized. Two other shallower thermal aquifers, with a temperature of 170-210°C, are identified. A circulation pattern of the geothermal fluids is also proposed. On the basis of calculations regarding the convective energy released by the geothermal system of Panarea, and the magmatic mass responsible for the positive gravimetric anomaly of the area, it was estimated that the last volcanic activity took place less then 10,000 years ago.
- F. Italiano and P. M. Nuccio
- Published Journal
- Journal of Volcanology and Geothermal Research, 1991
- Not Provided
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F. Italiano,P. M. Nuccio. 1991. Geochemical Investigations Of Submarine Volcanic Exhalations To The East Of Panarea, Aeolian Islands, Italy. Journal of Volcanology and Geothermal Research. (!) .