Active degassing of mantle-derived fluid: A geochemical study along the Vulture line, southern Apennines (Italy)

作者：Caracausi A; Martelli M; Nuccio P M; Paternoster M^*; Stuart F M

来源：Journal of Volcanology and Geothermal Research, 2013, 253: 65-74.

DOI：10.1016/j.jvolgeores.2012.12.005

• Southern Apennines
• Vulture line
• Helium and carbon isotopes
• Gas emissions

We report the results of a geochemical study of gas emissions along a NE-SW transect in southern Italy in order to test the hypothesis that the region around Monte Vulture is affected by degassing of mantle-derived fluids through a lithospheric discontinuity. We also investigated lavas from the Monte Vulture volcano displaying He-3/He-4 (up to similar to 6.0 Ra) and Sr isotopes that are consistent with an origin in mantle that has had minimal pollution from subducted Adriatic slab. Similar He-3/He-4 in fluids from around Mt. Vulture indicate that the deep volcanic system is still degassing. Mantle-derived He occurs in fluids along the length of the Vulture line, reinforcing the hypothesis that it is a deep tectonic discontinuity along which mantle fluids and/or melts advert to the surface. The CO2/He-3 ratios are highly variable (2.7 x 10(8)-2.15 x 10(11)) in response to processes such as gas dissolution into aquifers, addition of crustal gases and degassing fractionation. Published by Elsevier B.V.

• 出版日期2013-3-1