Paleohydrological records from peat profiles and speleothems in Sutherland, northwest Scotland

Paleohydrological changes during the late Holocene are inferred from humifi cation, testate amoebae, and pollen evidence from three blanket peat profil es in northwest Scotland, Replicate peat humification records from the Tral igill basin share the same patterns of change for a 600-yr period of overla p between 1800 and 2400 cal yr B.P. The shared patterns, inferred from samp les with a resolution of 5-13 yr,represent basinwide hydrological changes. In a nearby, but hydrologically separate, area with caves beneath peat, the luminescence emission wavelength measured in two speleothem samples correl ated with the humification record in the overlying peat, This correlation i mplies that speleothem luminescence emission wavelength depends primarily o n decay rates in the soils from which drip waters are derived, as long as t here is no major change in soil or vegetation. The peat and speleothem reco rds from the cave site further correlate with the peat records from the Tra ligill basin. Taken together, the records thus represent a regional climati c signal. Peaks in surface wetness replicated in two or more records occur at ca, 2300, 2090, 2030, 1820, 1600, and 1440 cal yr B.P. Further peaks occ ur at 800, 570, and 115 cal yr B.P. in the humification and stalagmite reco rds that extend to the present day. Correlative changes have been observed, not only in other peat records from Scotland but also in ice accumulation at GISP2, These further correlations imply that precipitation regimes in Sc otland and Greenland were in phase during the late Holocene. (C) 2001 Unive rsity of Washington.