Ischia Island represents only the remnant of a larger volcanic complex. To prove this hypothe-sis about 600 km of new marine and geophysical data were utilized. Results reveal that the western offshore of the island is mainly made by previously unreported E-W and NE-SW ridges that include several volcanic edifices. Interpretation of sea-borne magnetic data evi-dences a, good correlation between bathymetry and magnetic anomalies, indicating the presence of a larger volcanic system than what previously known, with evidences of deeper in-trusions of cooled magma. The deeper intrusions show NE-SW trends. Subvertical NE faults, visible on seismic and CHIRP data, delimit the volcanic ridges to the NW and upthrow the vol-canic basement towards the Island. Geophysical data indicate that the age of faulting is extremely recent and seem not triggered by volcanism. Tectonically controlled uplift phenomena outside the Ischia caldera raise doubts on the current interpretation of Mt. Epomeo as a resurgent dome.
The western undersea section of the Ischia volcanic complex (Italy, Tyrrhenian sea) inferred from marine geophysical data
de Alteriis G;
2002
Abstract
Ischia Island represents only the remnant of a larger volcanic complex. To prove this hypothe-sis about 600 km of new marine and geophysical data were utilized. Results reveal that the western offshore of the island is mainly made by previously unreported E-W and NE-SW ridges that include several volcanic edifices. Interpretation of sea-borne magnetic data evi-dences a, good correlation between bathymetry and magnetic anomalies, indicating the presence of a larger volcanic system than what previously known, with evidences of deeper in-trusions of cooled magma. The deeper intrusions show NE-SW trends. Subvertical NE faults, visible on seismic and CHIRP data, delimit the volcanic ridges to the NW and upthrow the vol-canic basement towards the Island. Geophysical data indicate that the age of faulting is extremely recent and seem not triggered by volcanism. Tectonically controlled uplift phenomena outside the Ischia caldera raise doubts on the current interpretation of Mt. Epomeo as a resurgent dome.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
