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Registros recuperados: 6
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Cryptotephrochronology of the Eemian and the last interglacial-glacial transition in the North East Atlantic ArchiMer
Abbott, Peter M.; Austin, William E. N.; Davies, Siwan M.; Pearce, Nicholas J. G.; Hibbert, Fiona D..
The Eemian interglacial and the onset of the subsequent glacial period serve as the most recent analogue for the natural operation of the climate system during the current interglacial. Pronounced climatic oscillations occurred during this period, but their nature and pattern are poorly understood due to dating limitations and unknown phase relationships between different regions and archives. Tephrochronology offers considerable potential for precise correlation of disparate palaeoclimatic archives preserving evidence of these rapid climatic transitions through the tracing of common isochronous tephra horizons. We outline the identification of three previously unknown cryptotephra horizons within a marine core from the Rockall Trough, North East Atlantic....
Tipo: Text Palavras-chave: Cryptotephra; Iceland; Isochrons; Palaeoclimatic correlation; Volcanic ash.
Ano: 2013 URL: https://archimer.ifremer.fr/doc/00264/37517/35822.pdf
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Tephrochronology and the extended intimate (integration of ice-core, marine and terrestrial records) event stratigraphy 8-128 ka b2k ArchiMer
Blockley, Simon P. E.; Bourne, Anna J.; Brauer, Achim; Davies, Siwan M.; Hardiman, Mark; Harding, Poppy R.; Lane, Christine S.; Macleod, Alison; Matthews, Ian P.; Pyne-o'Donnell, Sean D. F.; Rasmussen, Sune O.; Wulf, Sabine; Zanchetta, Giovanni.
The comparison of palaeoclimate records on their own independent timescales is central to the work of the INTIMATE (INTegrating Ice core, MArine and TErrestrial records) network. For the North Atlantic region, an event stratigraphy has been established from the high-precision Greenland ice-core records and the integrated GICCO5 chronology. This stratotype provides a palaeoclimate signal to which the timing and nature of palaeoenvironmental change recorded in marine and terrestrial archives can be compared. To facilitate this wider comparison, without assuming synchroneity of climatic change/proxy response, INTIMATE has also focussed on the development of tools to achieve this. In particular the use of time-parallel marker horizons e.g. tephra layers...
Tipo: Text Palavras-chave: Event-stratigraphy; Tephrochronology; INTIMATE; Greenland ice cores; Palaeoenvironment; Palaeoclimate.
Ano: 2014 URL: https://archimer.ifremer.fr/doc/00289/40028/39254.pdf
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A North Atlantic tephrostratigraphical framework for 130-60 ka b2k: new tephra discoveries, marine-based correlations, and future challenges ArchiMer
Davies, Siwan M.; Abbott, Peter M.; Meara, Rhian H.; Pearce, Nicholas J. G.; Austin, William E. N.; Chapman, Mark R.; Svensson, Anders; Bigler, Matthias; Rasmussen, Tine L.; Rasmussen, Sune O.; Farmer, Elizabeth J..
Building chronological frameworks for proxy sequences spanning 130-60 ka b2k is plagued by difficulties and uncertainties. Recent developments in the North Atlantic region, however, affirm the potential offered by tephrochronology and specifically the search for cryptotephra. Here we review the potential offered by tephrostratigraphy for sequences spanning 130-60 ka b2k. We combine newly identified cryptotephra deposits from the NGRIP ice-core and a marine core from the Iceland Basin with previously published data from the ice and marine realms to construct the first tephrostratigraphical framework for this time-interval. Forty-three tephra or cryptotephra deposits are incorporated into this framework; twenty three tephra deposits are found in the...
Tipo: Text Palavras-chave: Tephra; Cryptotephra; Tephrostratigraphy; Greenland ice-cores; North Atlantic marine cores; Iceland; Tephra correlations; Glass-shard analysis; Rapid climate changes.
Ano: 2014 URL: https://archimer.ifremer.fr/doc/00289/40029/39255.pdf
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Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls ArchiMer
Abbott, Peter M.; Griggs, Adam J.; Bourne, Anna J.; Davies, Siwan M..
Tephrochronology is increasingly being utilised as a key tool for improving chronological models and correlating disparate palaeoclimatic sequences. For many sedimentary environments, however, there is an increased recognition that a range of processes may impart a delay in deposition and/or rework tephra. These processes can affect the integrity of tephra deposits as time-synchronous markers, therefore, it is crucial to assess their isochronous nature, especially when cryptotephras are investigated in a dynamic marine environment. A methodology for the identification and characterisation of marine cryptotephras alongside a protocol for assessing their integrity is outlined. This methodology was applied to a wide network of North Atlantic marine sequences...
Tipo: Text Palavras-chave: Quaternary; Palaeoceanography; Tephrochronology; North Atlantic; Transport and deposition; Marine cores; Glass shard concentrations.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00495/60700/83609.pdf
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Tracing marine cryptotephras in the North Atlantic during the last glacial period: Improving the North Atlantic marine tephrostratigraphic framework ArchiMer
Abbott, Peter M.; Griggs, Adam J.; Bourne, Anna J.; Chapman, Mark R.; Davies, Siwan M..
Tephrochronology is increasingly being recognised as a key tool for the correlation of disparate palae-oclimatic archives, underpinning chronological models and facilitating climatically independent comparisons of climate proxies. Tephra frameworks integrating both distal and proximal tephra occurrences are essential to these investigations providing key details on their spatial distributions, geochemical signatures, eruptive sources as well as any available chronological and/or stratigraphic information. Frameworks also help to avoid mis-correlation of horizons and provide important information on volcanic history. Here we present a comprehensive chronostratigraphic framework of 14 tephra horizons from North Atlantic marine sequences spanning 60-25 cal ka...
Tipo: Text Palavras-chave: Quaternary; Palaeoceanography; Tephrochronology; North Atlantic; Tephra framework; Marine cores.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00495/60702/83611.pdf
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Optimising the use of marine tephrochronology in the North Atlantic: a detailed investigation of the Faroe Marine Ash Zones II, III and IV ArchiMer
Griggs, Adam J.; Davies, Siwan M.; Abbott, Peter M.; Rasmussen, Tine L.; Palmer, Adrian P..
Tephrochronology is central to the INTIMATE(1) goals for testing the degree of climatic synchroneity during abrupt climatic events that punctuated the last glacial period. Since their identification in North Atlantic marine sequences, the Faroe Marine Ash Zone II (FMAZ II), FMAZ III and FMAZ IV have received considerable attention due to their potential for high-precision synchronisation with the Greenland ice-cores. In order to optimise the use of these horizons as isochronous markers, a detailed re-investigation of their geochemical composition, sedimentology and the processes that deposited each ash zone is presented. Shard concentration profiles, geochemical homogeneity and micro-sedimentological structures are investigated for each ash zone preserved...
Tipo: Text Palavras-chave: North Atlantic; Tephra; Taphonomy; Synchronisation; Micromorphology.
Ano: 2014 URL: https://archimer.ifremer.fr/doc/00496/60734/65220.pdf
Registros recuperados: 6
Primeira ... 1 ... Última
 

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