The volcaniclastic deposits of the main caldera and the evolution of the Galluccio Tuff of Roccamonfina volcano, Southern Italy

2.50
Hdl Handle:
http://hdl.handle.net/10547/326089
Title:
The volcaniclastic deposits of the main caldera and the evolution of the Galluccio Tuff of Roccamonfina volcano, Southern Italy
Authors:
Cole, Paul David
Abstract:
The south-west portion of the main caldera was mapped and a stratigraphy for the caldera-fill was constructed. The exact timing of formation of the main caldera is unclear; However, caldera collapse either predates or was synchronous with the eruption of the Campagnola Tuff. The proximal facies of the Campagnola Tuff exists as a complex relation of ignimbrite, lithic breccia and pyroclastic surge deposits. Overlying this the Galluccio Tuff a compound ignimbrite, ~6 km3 D.R.E, forms the base of the exposed caldera fill. Caldera lakes then became well established and following activity was predominantly phreatomagmatic. Pyroclastic surge deposits possess sand wave structures of several types and their migration direction was apparently controlled by the velocity/flow regime of the surge rather than the moisutre content. The morphology of juvenile clasts from phreatomagmatic deposits indicates that the eruptions were driven by a combination of vesiculation and magma/water interaction. The uppermost pyroclastic deposits are thought to represent the early phase of dome building where water still had access to the vent. The construction of the lava domes brought activity to a close within the main caldera. The Galluccio Tuff on the flanks of the volcano may be divided into three compositionally distinct eruptive units. The Lower Galluccio Tuff, correlated with the bulk of the Galluccio Tuff filling the main caldera. The Middle Galluccio Tuff commenced with the eruption of pumice-rich pyroclastic flows followed by flows enriched in both the size and amount of lithic fragments forming lithic-rich ignimbrite and co-ignimbrite lithic breccias of which several types exist. The Upper Galluccio Tuff is composed of lithic-rich ignimbrite which possess dense pumice fragments and are thought to be the product of a combination of both vesiculation and magma water interaction. Field relations indicate that pyroclastic flows were sometimes generated in quick succession and may have overrun earlier slower moving flows. Occasionally internal shear may have caused the overriding of portions of the same flow, these often coincide with lithic breccias and represent the climax of the eruptive phases. The grading of lithic fragments indicates that the expansion and fluidization decreased and yield strength increased with time in a pyroclastic flow.
Citation:
Cole, P.D. (1990) 'The Volcaniclastic Deposits of the Main Caldera and the Evolution of the Galluccio Tuff of Roccamonfina Volcano, Southern Italy'. PhD thesis. Luton College of Higher Education.
Publisher:
University of Bedfordshire
Issue Date:
Jul-1990
URI:
http://hdl.handle.net/10547/326089
Type:
Thesis or dissertation
Language:
en
Description:
A thesis submitted in partial fulfilment of the requirements of the Council for National Academic Awards for the degree of Doctor of Philosophy
Appears in Collections:
PhD e-theses

Full metadata record

DC FieldValue Language
dc.contributor.authorCole, Paul Daviden
dc.date.accessioned2014-09-12T08:46:37Z-
dc.date.available2014-09-12T08:46:37Z-
dc.date.issued1990-07-
dc.identifier.citationCole, P.D. (1990) 'The Volcaniclastic Deposits of the Main Caldera and the Evolution of the Galluccio Tuff of Roccamonfina Volcano, Southern Italy'. PhD thesis. Luton College of Higher Education.en
dc.identifier.urihttp://hdl.handle.net/10547/326089-
dc.descriptionA thesis submitted in partial fulfilment of the requirements of the Council for National Academic Awards for the degree of Doctor of Philosophyen
dc.description.abstractThe south-west portion of the main caldera was mapped and a stratigraphy for the caldera-fill was constructed. The exact timing of formation of the main caldera is unclear; However, caldera collapse either predates or was synchronous with the eruption of the Campagnola Tuff. The proximal facies of the Campagnola Tuff exists as a complex relation of ignimbrite, lithic breccia and pyroclastic surge deposits. Overlying this the Galluccio Tuff a compound ignimbrite, ~6 km3 D.R.E, forms the base of the exposed caldera fill. Caldera lakes then became well established and following activity was predominantly phreatomagmatic. Pyroclastic surge deposits possess sand wave structures of several types and their migration direction was apparently controlled by the velocity/flow regime of the surge rather than the moisutre content. The morphology of juvenile clasts from phreatomagmatic deposits indicates that the eruptions were driven by a combination of vesiculation and magma/water interaction. The uppermost pyroclastic deposits are thought to represent the early phase of dome building where water still had access to the vent. The construction of the lava domes brought activity to a close within the main caldera. The Galluccio Tuff on the flanks of the volcano may be divided into three compositionally distinct eruptive units. The Lower Galluccio Tuff, correlated with the bulk of the Galluccio Tuff filling the main caldera. The Middle Galluccio Tuff commenced with the eruption of pumice-rich pyroclastic flows followed by flows enriched in both the size and amount of lithic fragments forming lithic-rich ignimbrite and co-ignimbrite lithic breccias of which several types exist. The Upper Galluccio Tuff is composed of lithic-rich ignimbrite which possess dense pumice fragments and are thought to be the product of a combination of both vesiculation and magma water interaction. Field relations indicate that pyroclastic flows were sometimes generated in quick succession and may have overrun earlier slower moving flows. Occasionally internal shear may have caused the overriding of portions of the same flow, these often coincide with lithic breccias and represent the climax of the eruptive phases. The grading of lithic fragments indicates that the expansion and fluidization decreased and yield strength increased with time in a pyroclastic flow.en
dc.language.isoenen
dc.publisherUniversity of Bedfordshireen
dc.subjectF640 Earth Scienceen
dc.subjectvolcanoesen
dc.subjectRoccamonfinaen
dc.subjectvulcanismen
dc.subjectgeologyen
dc.subjectignimbriteen
dc.subjectlithic brecciaen
dc.subjectpyroclastic surge depositsen
dc.titleThe volcaniclastic deposits of the main caldera and the evolution of the Galluccio Tuff of Roccamonfina volcano, Southern Italyen
dc.typeThesis or dissertationen
dc.type.qualificationnamePhDen_GB
dc.type.qualificationlevelPhDen
dc.publisher.institutionUniversity of Bedfordshireen
This item is licensed under a Creative Commons License
Creative Commons
All Items in UOBREP are protected by copyright, with all rights reserved, unless otherwise indicated.