Vegetation history of the marine isotope stage 7 interglacial complex at Ioannina, NW Greece

• Main Authors: K H Roucoux, P C Tzedakis, Mick Frogley, I T Lawson, R C Preece
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2008
• Subjects: Uncategorised value; North Atlantic
• Online Access: https://figshare.com/articles/journal_contribution/Vegetation_history_of_the_marine_isotope_stage_7_interglacial_complex_at_Ioannina_NW_Greece/23321075

A new pollen record of the penultimate interglacial complex, corresponding approximately to marine isotope stage (MIS) 7 (ca 186,000245,000 years before present), has been generated in core I-284 from the Ioannina basin in northwest Greece. It represents the highest resolution terrestrial record for this interval available to date, with a mean sampling interval of 200 years. The sequence records four forested intervals, correlated with MIS 7e, 7c, 7a and a sub-orbital-scale event following 7a but within MIS 7. The longest and most complete warm stage in terms of vegetational succession is MIS 7c, while the succession in MIS 7e appears to be truncated by a shift to colder, drier climatic conditions. The results of biomisation suggest that during all of these intervals winter temperatures in NW Greece remained lower than during the Eemian or Holocene, while smaller populations of sclerophyllous taxa indicate that summers may have been wetter. Intervening intervals of open vegetation are correlated with MIS 7d, 7b and an oscillation following 7a. Low tree pollen percentages during MIS 7d are interpreted as reflecting very cold and dry conditions, concomitant with a period of low northern hemisphere insolation which resulted from a rare combination of minimum obliquity and maximum precession. Higher tree pollen percentages throughout MIS 7b, by contrast, are indicative of relatively mild conditions, in agreement with marine temperature and ice volume records. Sub-orbital scale oscillations in tree population extent are also recorded in the new I-284 record suggesting that, just as in the last climatic cycle, NW Greece was affected by rapid climatic oscillations that are associated with changes in the North Atlantic.