 |
| Titel |
Annual proxy data from Lago Grande di Monticchio (southern Italy) between 76 and 112 ka: new chronological constraints and insights on abrupt climatic oscillations |
| VerfasserIn |
C. Martín-Puertas, A. Brauer, S. Wulf, F. Ott, S. Lauterbach, P. Dulski |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1814-9324
|
| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 10, no. 6 ; Nr. 10, no. 6 (2014-12-01), S.2099-2114 |
| Datensatznummer |
250117081
|
| Publikation (Nr.) |
 copernicus.org/cp-10-2099-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| We present new annual sedimentological proxies and sub-annual element scanner
data from the Lago Grande di Monticchio (MON) sediment record for the
sequence 76–112 thousand years before present (ka). They are combined with
the previously published decadal to centennial resolved pollen assemblage in
order to provide a comprehensive reconstruction of six major abrupt stadial
spells (MON 1–6) in the central Mediterranean during the early phase of the last
glaciation. These climatic oscillations are defined by intervals of thicker
varves and high Ti-counts and coincide with episodes of forest depletion
interpreted as Mediterranean stadial conditions (cold winter/dry summer). Our
chronology, labelled as MON-2014, has been updated for the study interval by
tephrochronology and repeated and more precise varve counts and is
independent from ice-core and speleothem chronologies. The high-resolution
Monticchio data then have been compared in detail with the Greenland ice-core
δ18O record (NorthGRIP) and the northern Alps speleothem
δ18Ocalcite data (NALPS). Based on visual inspection of
major changes in the proxy data, MON 2–6 are suggested to correlate with
Greenland stadials (GS) 25–20. MON 1 (Woillard event), the first and
shortest cooling spell in the Mediterranean after a long phase of stable
interglacial conditions, has no counterpart in the Greenland ice core, but
coincides with the lowest isotope values at the end of the gradual decrease
in δ18Oice in NorthGRIP during the second half of the
Greenland interstadial (GI) 25. MON 3 is the least pronounced cold spell and
shows gradual transitions, whereas its NorthGRIP counterpart GS 24 is
characterized by sharp changes in the isotope records. MON 2 and MON 4 are
the longest and most pronounced oscillations in the MON sediments in good
agreement with their counterparts identified in the ice and spelethem
records. The length of MON 4 (correlating with GS 22) supports the duration
of stadial proposed by the NALPS timescales and suggests ca. 500 year longer
duration than calculated by the ice-core chronologies
GICC05modelext and AICC2012. Absolute dating of the cold spells
provided by the MON-2014 chronology shows good agreement among the MON-2014,
the GICC05modelext and the NALPS timescales for the period
between 112 and 100 ka. In contrast, the MON-2014 varve chronology dates the
oscillations MON 4 to MON 6 (92–76 ka) as ca. 3500 years older than the most
likely corresponding stadials GS 22 to GS 20 by the other chronologies. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|