Integrated approach for the reconstruction of stratigraphy and geology of Quaternary volcanic terrains: An application to the Vulsini Volcanoes (central Italy)

Abstract

Modern stratigraphic studies and field mapping of Quaternary volcanic terrains require a multidisciplinary approach for the reconstruction of the time-space history of a volcanic area (e.g., activity phases, eruptive sources, compositional changes, volcano build-up and collapse events) within the framework of concomitant and/or genetically related geological events acting on regional to global scales (e.g., tectonism, climate changes, glacio-eustatism). Here, we report recent results on the stratigraphy, structure, and evolution of the southern part of the Vulsini volcanic district (0.6-0.1 Ma), Roman Province, in the light of a new geological survey for the 1:50,000 map of Italy (CARG Project). We focus on the integration of different kinds of stratigraphic units, including lithostratigraphic, lithosomatic, and unconformity-bounded stratigraphic (UBS) units, to define and group mappable volcanic bodies. Lithostratigraphic units are characterized in terms of textural features, indicative of eruptive and emplacement scenarios, and rock-type compositions. The intervening stratigraphic discontinuities are defined in terms of nature, position, and areal extent, and they are attributed to local depositional processes versus significant temporal hiatuses in the eruptive activity or regional and interregional geological events. The mapped volcanic units are thus correlated to lithosomatic units, corresponding to volcanic source edifices, as well as to the local and regional UBS unit settings recently defined for the Tyrrhenian coast nearby. On these grounds, we illustrate the geological evolution of the study area as the interplay of constructional and destructional volcanic activity, erosion, pedogenesis, secondary volcaniclastic sedimentation during intereruptive periods, and sea-level fluctuations

Origins and energetics of maar volcanoes: examples from the ultrapotassic Sabatini Volcanic District (Roman Province, Central Italy)

“…ranging in composition from K basalts and trachybasalts in the Valle Latina to shoshonitesphonotephrites at Vulsini and K-foidites at Colli Albani; Dolfi et al 2011;Palladino et al 2010;Sottili et al 2009) were involved in hydromagmatic activity. On the other hand, the SVD parallels the Campi Flegrei case, where both end members of the magma differentiation line (respectively SiO 2 -poor trachybasalts-phonotephrites and SiO 2 -rich trachytes-phonolites; Mastrolorenzo et al 2001;De Astis et al 2004) produced tuff cones and tuff rings typical of relatively small-scale hydromagmatic activity, although with inferred different modes and boundary conditions of magma-water interaction due to remarkably different rheological behaviours of interacting magmas.…”

“…Stratigraphic discontinuities among eruptive units from different source vents mostly occur as paleosols or, subordinately, as extensive erosional surfaces (e.g. see Palladino et al 2010 for an application of integrated lithostratigraphic and unconformity-bounded stratigraphic approaches to Quaternary volcanic terrains). The polyge- Numbers refer to the location map in Fig.…”

The Vesuvius and the other volcanoes of Central Italy

“…The Vulsini district is made up by the coalescence of five large volcanic edifices (inset of Fig. 85): palaeo-Bolsena, Bolsena, South Vulsini Plateau, Montefiascone and Latera volcanoes (Nappi et al, , 1998Palladino et al, 2010). The vulsinian volcanic rocks cover an area larger than 2,000 km 2 , filling up a depression represented by the southern continuation of the Siena-Radicofani and Paglia-Tevere grabens.…”

“…The Bolsena volcanic complex began its activity after the formation of the palaeo-Bolsena caldera and lasted for few hundred thousand years , and references therein). It developed mainly in the i t i n e r a r y 108 eastern sector of the Vulsinian district with the formation of a large caldera depression partly occupied by the Bolsena Lake and produced two thick ignimbrite sheets, fall deposits and lava flows which built an ignimbrite shield (Freda et al, 1990;Nappi et al, 1998;Palladino et al, 2010). Fissural lava flows, formed a lava plateau south of Bolsena Lake in the Marta-Tuscania area (Palladino et al, 1994).…”

New seismo-stratigraphic and marine magnetic data of the Gulf of Pozzuoli (Naples Bay, Tyrrhenian Sea, Italy): inferences for the tectonic and magmatic events of the Phlegrean Fields volcanic complex (Campania)

“…New stratigraphic and volcanological studies, mainly onshore, dealing with the definition of volcanological units during the field survey and specific volcanological features, petrographic, geochemical and petrological studies and geophysical models have been recently presented (Lucchi et al 2010;Tibaldi 2010;Bonomo and Ricci 2010;Palladino et al 2010;Milia 2010;Perrotta et al 2010;De Vita et al 2010). These studies allowed us to delineate the problems related to stratigraphy and volcanology of active volcanic districts of southern Italy, referring in particular to Naples Bay.…”