Australian dust deposits: modern processes and the Quaternary record
A detailed record of the deglaciation history of the penultimate glacial to interglacial transition is given, mainly based on the stable isotopes of calcium carbonate-containing lake sediments in a glacially excavated depression below the city of Amsterdam. Initially, this depression, the Amsterdam Basin, formed part of a lake covering the western and central part of the Netherlands and extending for an unknown distance into the present North Sea. Annual layer counting shows that the lake drained after about a millennium, leaving shallow pools in the remaining depressions. The latter changed again into larger and deeper lakes including the Holland Lake during the rise of sea level in the early Eemian. Oxygen isotope values of the early lake sediments indicate an interglacial summer climate, but the nearness of dead-ice fields caused severe winters. The isotope record is furthermore characterized by the influx of large amounts of isotopically light water supplied by the river Rhine. A change to much colder conditions occurred simultaneously with the draining of the Holland Lake, as appears from oxygen isotope values and the sudden increase in non-arboreal pollen. This interval is correlated with the Kattegat Stadial and the sea-level standstill of Aladdins Cave on the Huon Peninsula of New Guinea. A short climate wiggle occurs at the end of this interval. The onset of the Eemian is marked by a rapid warming of 5àwhich extends into local pollen-zone E3. Provided that our correlation of this cold interval with the sea-level standstill of Aladdins Cave is correct, the time interval between the earliest lake sediments in the Amsterdam Basin and the Eemian highstand took about 5-6 millennia.
Quaternary Science Reviews
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