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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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Farmer, Elizabeth J.; Chapman, Mark R.; Andrews, Julian E.. |
A high-resolution record of Mg/Ca ratios from the planktonic foraminifer Globigerina bulloides has been produced for IMAGES core MD99-2251 from the subpolar North Atlantic. The record extends from the Younger Dryas-Preboreal transition through the Holocene at similar to 70 year resolution, with a more detailed section at similar to 20 year resolution through the interval encompassing the major cooling episode 8200 years ago. Mg/Ca derived temperatures show significant variations through the Holocene, with surface temperatures ranging from similar to 8 to 13 degrees C. The onset of the Holocene is marked by an abrupt warming, with a further increase in early Holocene temperatures occurring prior to 9.5 ka. This is followed by a mid-Holocene period of cooler... |
Tipo: Text |
Palavras-chave: Planktonic foraminifera; Mg/Ca; G. bulloides; North Atlantic; Holocene. |
Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00236/34760/33396.pdf |
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