0000000000969184
AUTHOR
E Gagliano Candela
Hydrothermal circulation on Ischia Island (Southern Italy), revealed by an integrated geochemical, geophysical and geological approach
Volcano-hosted hydrothermal systems are complex geological objects, whose thorough characterisation requires extensive and interdisciplinary work. Indeed, even thought geological, geochemical and geophysical observations offer highly significant but independent information, only an integrated multidisciplinary approach can yield a comprehensive characterisation of the chemical/physical structure of hydrothermal systems. Notwithstanding the extensive application of geological, geochemical and geophysical techniques in geothermal research, there are only a few examples in the literature of concurrent use of the three techniques [Finizola et al., 2002; Zlotnicki et al., 2009]; these studies ov…
The Ischia Island hydrothermal system: an integrated multidisciplinary (geochemical, geophysical and geological) study
Ischia Island is the emergent portion of a large volcanic complex on the Gulf of Naples (Southern Italy). Ischia volcano has undertaken a complex evolution since 150 ka b.p., with prolonged cycles of effusive and explosive eruptions alternated with quiescence periods (the most recent of which started after the 1302 A.D. Arso eruption). Currently, hot springs (with discharge temperature up to 90 C), fumarolic gas emissions with CO2 up to 97%, and diffuse soil degassing testify a persistent activity state of the Ischia volcano. Ischia Island is a very good example of an active volcano hosting a large hydrothermal system and, in particular, its south-western sector has long been known to be th…
GEOCHEMICAL AND GEOPHYSICAL RESEARCH AIMED AT CHARACTERIZING THE HYDRO-GEOLOGICAL STRUCTURES OF A KARST FORMATION
Geochemical and geophysical research was effected in an area between the Madonia mountain range and the coast around the Rock of Cefalù, at the base of which there are a number of large-sized springs. The aim of the study was to reconstruct the buried hydro-geological structures that carry the waters from the Madonia Mountains to the areas along the coast where they surface. The Madonia Mountains are prevalently made up of carbonatic formations and terrigenous deposits of the Numidian Flysch. Outcrops of the Cozzo Terravecchia formation are also present, as are Messinian evaporitic deposits and recent detritic deposits of alluvial and marine origin. The Karst processes that develop in the l…
The structure of a hydrothermal system from an integrated geochemical, geophysical and geological approach: the Ischia Island case study
The complexity of volcano-hosted hydrothermal systems is such that thorough characterisation requires extensive and interdisciplinary work. We use here an integrated multidisciplinary approach, combining geological investigations with hydrogeochemical and soil degassing prospecting, and resistivity surveys, to provide a comprehensive characterisation of the shallow structure of the south-western Ischia’s hydrothermal system. We show that the investigated area is characterised by a structural setting that, although very complex, can be schematised in three sectors, namely the extra caldera sector (ECS), caldera floor sector (CFS), and resurgent caldera sector (RCS). This contrasted structura…