30 Isotope Stage 11: An Analog for the Present Interglaciation?

Saturday, 26 July 2003
8:00 AM - 12:00 PM

NATURE AND TIMING OF VEGETATION CHANGES IN S. EUROPE DURING MIS 11

Paper number: 30-9
Program: SYMPOSIA
Time: 10:50 AM – 11:10 AM

Authors

Abstract

In contrast to the situation in higher latitudes where the effects of glacial and periglacial processes have produced stratigraphical discontinuities, favourable geological conditions in southern Europe have led to the relatively undisturbed accumulation of thick sedimentary Quaternary sequences. Such sequences provide an opportunity to develop complete and high-resolution records of terrestrial events over multiple glacial-interglacial cycles and bypass the problem of reconstructing a record by piecing it together from isolated deposits of often-uncertain chronostratigraphical position. Thus, unlike northern Europe where the terrestrial equivalent of MIS 11 remains a controversial issue, its position within these long sequences can be determined with increased confidence. In addition, the continuity of the records provides an opportunity to examine not only the full interglacial sequence, but also the intervals pre- and post-dating it, which are not represented in fragmentary records. However, despite a clear chronostratigraphical framework, these long sequences still lack a sufficiently precise terrestrial timescale because of problems associated with direct dating of lake sediment material. The development of chronologies for these long sequences is of critical importance because we need to assess how terrestrial events relate temporally to atmospheric and ocean changes to determine the forcing factors and differences in response characteristics.

Here we review the nature of vegetation changes in southern Europe during the MIS 11 complex. We then develop a chronology for these events and test the accuracy of the devised timescale. This allows comparisons to be made with records of climate variability from the North Atlantic on orbital and suborbital timescales. Of particular interest is to examine the extent to which marine and terrestrial stage boundaries coincide. More specifically, do forest communities persist in southern Europe throughout the 30 kyr interval of minimum ice volume or do they vary in abundance in response to insolation changes?