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dc.contributor.authorSagnotti, Leonardo
dc.contributor.authorGiaccio, Biagio
dc.contributor.authorLiddicoat, Joseph C.
dc.contributor.authorNomade, Sebastien
dc.contributor.authorRenne, Paul R.
dc.contributor.authorScardia, Giancarlo [UNESP]
dc.contributor.authorSprain, Courtney J.
dc.date.accessioned2018-11-26T15:28:34Z
dc.date.available2018-11-26T15:28:34Z
dc.date.issued2016-02-01
dc.identifierhttp://dx.doi.org/10.1093/gji/ggv486
dc.identifier.citationGeophysical Journal International. Oxford: Oxford Univ Press, v. 204, n. 2, p. 798-812, 2016.
dc.identifier.issn0956-540X
dc.identifier.urihttp://hdl.handle.net/11449/158671
dc.description.abstractA recent study of the Matuyama-Brunhes (M-B) geomagnetic field reversal recorded in exposed lacustrine sediments from the Sulmona Basin (Italy) provided a continuous, high-resolution record indicating that the reversal of the field direction at the terminus of the M-B boundary (MBB) occurred in less than a century, about 786 ka ago. In the sediment, thin (4-6 cm) remagnetized horizons were recognized above two distinct tephra layers-SUL2-19 and SUL2-20-that occur similar to 25 and similar to 35 cm below the MBB, respectively. Also, a faint, millimetre-thick tephra (SUL2-18) occurs 2-3 cm above the MBB. With the aim of improving the temporal resolution of the previous Sulmona MBB record and understanding the possible influence of cryptotephra on the M-B record in the Sulmona Basin, we performed more detailed sampling and analyses of overlapping standard and smaller samples from a 50 cm-long block that spans the MBB. The new data indicate that (i) the MBB is even sharper than previously reported and occurs similar to 2.5 cm below tephra SUL2-18, in agreement with the previous study; (ii) the MBB coincides with the rise of an intensity peak of the natural remanent magnetization (NRM) intensity, which extends across SUL2-18; (iii) except for a 2-cm-thick interval just above tephra SUL2-18, the rock magnetic parameters (k, ARM, M-r, M-s, B-c, B-cr) indicate exactly the same magnetic mineralogy throughout the sampled sequence. We conclude that either SUL2-18 resulted in the remagnetization of an interval of about 6 cm (i.e. during the NRM intensity peak spanning similar to 260 +/- 110 yr, according to the estimated local sedimentation rate), and thus the detailed MBB record is lost because it is overprinted, or the MBB is well recorded, occurred abruptly about 2.5 cm below SUL2-18 and lasted less than 13 +/- 6 yr. Both hypotheses challenge our understanding of the geomagnetic field behaviour during a polarity transition and/or of the NRM acquisition process in the Sulmona lacustrine sediment.en
dc.format.extent798-812
dc.language.isoeng
dc.publisherOxford Univ Press
dc.relation.ispartofGeophysical Journal International
dc.sourceWeb of Science
dc.subjectPalaeomagnetic secular variation
dc.subjectRapid time variations
dc.subjectReversals: process, time scale, magnetostratigraphy
dc.subjectRock and mineral magnetism
dc.titleHow fast was the Matuyama-Brunhes geomagnetic reversal? A new subcentennial record from the Sulmona Basin, central Italyen
dc.typeArtigo
dcterms.licensehttp://www.oxfordjournals.org/access_purchase/self-archiving_policyb.html
dcterms.rightsHolderOxford Univ Press
dc.contributor.institutionIst Nazl Geofis & Vulcanol
dc.contributor.institutionCNR
dc.contributor.institutionColumbia Univ
dc.contributor.institutionCEA CNRS UVSQ
dc.contributor.institutionUniv Paris Saclay
dc.contributor.institutionBerkeley Geochronol Ctr
dc.contributor.institutionUniv Calif Berkeley
dc.contributor.institutionUniversidade Estadual Paulista (UNESP)
dc.description.affiliationIst Nazl Geofis & Vulcanol, I-00143 Rome, Italy
dc.description.affiliationCNR, Ist Geol Ambientale & Geoingn, I-00015 Monterotondo, Rome, Italy
dc.description.affiliationColumbia Univ, Barnard Coll, New York, NY 10027 USA
dc.description.affiliationCEA CNRS UVSQ, IPSL, UMR8212, Lab Sci Climat & Environm, F-91190 Gif Sur Yvette, France
dc.description.affiliationUniv Paris Saclay, F-91190 Gif Sur Yvette, France
dc.description.affiliationBerkeley Geochronol Ctr, Berkeley, CA 94709 USA
dc.description.affiliationUniv Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94709 USA
dc.description.affiliationUniv Estadual Paulista, Inst Geociencias & Ciencias Exatas, BR-13506900 Rio Claro, SP, Brazil
dc.description.affiliationUnespUniv Estadual Paulista, Inst Geociencias & Ciencias Exatas, BR-13506900 Rio Claro, SP, Brazil
dc.identifier.doi10.1093/gji/ggv486
dc.identifier.wosWOS:000368427100010
dc.rights.accessRightsAcesso aberto
dc.identifier.fileWOS000368427100010.pdf
unesp.author.orcid0000-0003-3944-201X[1]
unesp.author.orcid0000-0002-7007-9127[2]
unesp.author.orcid0000-0003-3710-7197[6]
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