Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/5383
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dc.contributor.authorallScardia, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italiaen
dc.contributor.authorallMuttoni, G.; Università di Milanoen
dc.date.accessioned2009-12-23T15:18:26Zen
dc.date.available2009-12-23T15:18:26Zen
dc.date.issued2009en
dc.identifier.urihttp://hdl.handle.net/2122/5383en
dc.description.abstractFacies analysis applied to several up to 220-m-deep cores, taken by Regione Lombardia in the central-northern Po Plain, allowed to recognize an overall regressive sequence consisting of cyclotemic shallow marine and fluvial-deltaic deposits overlain by distal to proximal braidplain sediments. Magnetostratigraphy, coupled with calcareous nannoplankton biostratigraphy, was used to date marine and fluvial-deltaic sediments to the early Pleistocene and continental sediments to the middle–late Pleistocene. Sediment accumulation rates were of ~0.3-0.4 mm/yr in the early Pleistocene, whereas an overall reduction in sediment accumulation rates to ~0.06-0.08 mm/yr, associated to relevant unconformities, characterized the middle-late Pleistocene. Stratigraphic evidences from petrographic, sedimentologic and palynologic analyses highlight in the Regione Lombardia cores a drastic reorganization of vegetational, fluvial, and Alpine drainage patterns, associated to a sequence boundary termed the “R surface”. The “R surface”, seismically traceable across the Po Plain subsurface, was constrained magnetostratigraphically to the first prominent Pleistocene glacio-eustatic lowstand of marine isotope stage (MIS) 22 at 0.87 Ma at the end of the Mid-Pleistocene Revolution, when climate worsened globally and locally caused the onset of the first major Pleistocene glaciation in the Alps. Most marine deposits in the cores lie above sea level highstands of corresponding age, suggesting that they have been uplifted. In order to estimate the observed rock uplift, sediments were back-stripped to elevations at times of deposition (expressed in meters above current sea level) by applying a simple Airy compensation model. The correlation of the isostatically corrected sedimentary facies to a glacio-eustatic reference curve obtained from classic oxygen isotope studies highlights a positive elevation mismatch (rock uplift) in the range of 70-120 m, which occurred after the onset of the major Pleistocene glacial-interglacial cycles at rates of at least 0.15-0.09 mm/yr. Although the driving forces of the observed rock uplift cannot be unambiguously identified, but its timing of onset after the beginning of the major Pleistocene glacial-interglacial cycles and the low seismicity observed in the most of the Regione Lombardia area seem to point to an isostatic readjustment of the chain probably due to the long-term erosional removal of sediments during major Pleistocene glacial advances.en
dc.language.isoItalianen
dc.publisher.nameIstituto Lombardo Accademia di Scienze e Lettereen
dc.relation.ispartofRendiconti Istituto Lombardoen
dc.relation.ispartofseries/ (2009)en
dc.subjectPleistoceneen
dc.subjectPo Plainen
dc.subjectpaleomagnetismen
dc.subjectglaciationen
dc.subjectrock upliften
dc.titleIl contributo dei pozzi perforati dalla Regione Lombardia alla conoscenza del Pleistocene lombardoen
dc.typearticleen
dc.description.statusPublisheden
dc.type.QualityControlPeer-revieweden
dc.subject.INGV02. Cryosphere::02.03. Ice cores::02.03.05. Paleoclimateen
dc.subject.INGV04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformationsen
dc.subject.INGV04. Solid Earth::04.03. Geodesy::04.03.03. Gravity and isostasyen
dc.subject.INGV04. Solid Earth::04.04. Geology::04.04.02. Geochronologyen
dc.subject.INGV04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transporten
dc.subject.INGV04. Solid Earth::04.04. Geology::04.04.10. Stratigraphyen
dc.subject.INGV04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetismen
dc.description.obiettivoSpecifico3.2. Tettonica attivaen
dc.description.journalTypeN/A or not JCRen
dc.description.fulltextopenen
dc.contributor.authorScardia, G.en
dc.contributor.authorMuttoni, G.en
dc.contributor.departmentIstituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Milano, Milano, Italiaen
item.openairetypearticle-
item.cerifentitytypePublications-
item.languageiso639-1it-
item.grantfulltextopen-
item.openairecristypehttp://purl.org/coar/resource_type/c_18cf-
item.fulltextWith Fulltext-
crisitem.author.deptInstituto Oceanográfico, Universidade de São Paulo, São Paulo, Brazil-
crisitem.classification.parent02. Cryosphere-
crisitem.classification.parent04. Solid Earth-
crisitem.classification.parent04. Solid Earth-
crisitem.classification.parent04. Solid Earth-
crisitem.classification.parent04. Solid Earth-
crisitem.classification.parent04. Solid Earth-
crisitem.classification.parent04. Solid Earth-
crisitem.department.parentorgIstituto Nazionale di Geofisica e Vulcanologia-
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