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Revisiting the Faroe Marine Ash Zone III in two Greenland ice cores: implications for marine‐ice correlations
Author(s) -
BOURNE A. J.,
DAVIES S. M.,
ABBOTT P. M.,
RASMUSSEN S. O.,
STEFFENSEN J. P.,
SVENSSON A.
Publication year - 2013
Publication title -
journal of quaternary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 94
eISSN - 1099-1417
pISSN - 0267-8179
DOI - 10.1002/jqs.2663
Subject(s) - tephra , geology , ice core , stadial , tephrochronology , basalt , geochemistry , volcano , paleontology , oceanography , holocene
Nineteen new Icelandic tephra layers are identified in NGRIP and NEEM ice spanning Greenland Interstadial‐9 (GI‐9) and the early phase of GI‐8 (∼38 000–40 500 b2k). Fourteen tephras are identified in the NGRIP record and five direct correlatives are identified in NEEM, thus indicating the occurrence of 14 separate volcanic events. With two exceptions, the tephras are tholeiitic basalt in composition and despite having very similar geochemical signatures can, in most cases, be discriminated from one another using their TiO 2 values. All of these tephra layers fall within the compositional range of the Faroe Marine Ash Zone III (FMAZ III) deposit previously identified in ocean cores from the Faroes region and previously correlated to NGRIP 2066.95 m by Davies et al . ([Davies SM, 2010]). Thus, the FMAZ III in the marine realm is most likely a complex ash zone that represents a series of closely timed Grimsvötn eruptions that, as yet, can only be stratigraphically separated in the high‐resolution ice‐core records. The geochemical signatures and stratigraphic positions of the new ice‐core layers means that the FMAZ III tephra deposit, as currently defined in the marine realm, cannot be correlated to NGRIP 2066.95 m or any other ice‐core tephra horizons preserved during this interval.