Climate-related variations in the composition of the Lateglacial and EarlyHolocene sediments of Lake Perespilno (eastern Poland)

This paper presents an array of analyses of the laminated sediments of Lake Perespilno, eastern Poland, covering the period between Older Dryas and Pr eboreal. Using the varve chronologies, pollen and C-14 data, the laminated sequence of Lake Perespilno has been synchronised with that of Lake Gosciaz . The length of the Allerod and Younger Dryas periods, derived from Lake Pe respilno sediments, agrees well with the previous estimates. According to o ur data, the climate in the Allerod was relatively mild, with some increase of precipitation and humidity after ca. 13.2 kyr cal BP. The beginning of the Younger Dryas is marked by drastic changes in temperature as well as hu midity. Thinning of forests facilitated input of allochtonous material to t he lake. It seems that the groundwater level as well as lake level dropped significantly, and the period of lowest water table was prolonged for ca. 3 00 years. Surprisingly, the abrupt warming at the beginning of the Holocene is only slightly reflected in the sediments. Changes in sediment compositi on at that time seem to be controlled more by the development of surroundin g Vegetation than by the climate itself (C) 1999 Elsevier Science Ltd. All rights reserved.