Publication Date:
2017-04-04
Description:
Eastern Sicily (southern Italy) is characterised by the presence of many natural gas emissions (mofettes, mud volcanoes).
These gases are mostly carbon dioxide and methane, with minor amounts of helium, hydrogen, carbon monoxide
and hydrocarbons. In this study, the extent and orientation of soil gas anomalies (He and CO2) were
investigated on a wide area (approximately 110 km2) located just SW of Mt. Etna. From a structural point of view,
this area lays on a typical foredeep–foreland system that marks the boundary between the southern part of the Eurasian
plate and the northern part of the African plate in the central Mediterranean. No tectonic structure was revealed
in this area by surface geological surveys. Very high soil emissions were found, and their spatial pattern reveals the
existence of some active faults all directed about N508E. This direction coincides with that of two major fault systems
that cut eastern Sicily and are evident, respectively, NE and SW of the study area. Soil gas data suggest that these fault
systems are the expression of a single continuous structural line which is probably responsible for the past and present
magma uprise in eastern Sicily. Isotopic values of carbon of CO2 suggest a minor contribution of organic carbon.
Moreover, in the highest degassing sites the isotopic values of He found in association with CO2 (He
abundance¼11–70 p.p.m.; R/Ra between 6.0 and 6.2) suggest that both gases are mantle derived. The extent of
the areas affected by high gas emissions and the amounts of deep CO2 emitted in the investigated area (several hundred
tonnes per day) may provide additional supporting evidence of a mantle upwelling taking place beneath this
region.
Description:
Gruppo Nazionale per la Vulcanologia Italy.
Description:
Published
Description:
273–284
Description:
partially_open
Keywords:
CO2
;
diffuse degassing
;
Sicily
;
04. Solid Earth::04.02. Exploration geophysics::04.02.01. Geochemical exploration
;
04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
;
04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
597 bytes
Format:
866788 bytes
Format:
text/html
Format:
application/pdf
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