High-Resolution Paleotemperature Proxy Record for the Last Interglaciation Based on Norwegian Speleothems

Abstract

Two speleothems from a coastal lowland and an alpine cave site in northern Norway grew in isotopic equilibrium during Termination II and marine isotope stage 5 (150,000-80,000 yr B.P.), as dated by the U-series technique. The stable isotope record (δ 18 O, δ 13 C) displays a time resolution down to ∼20 yr. The δ 18 O c signal in the two speleothems appears to be mainly dominated by the meteoric signal; i.e., there is a positive relationship between δ 18 O c and temperature [∂(δ 18 O c /∂T > 0]. The FM-2 couplet, a Younger Dryas type two-step structure in Termination II at 132,000 ± 5000 and 129,000 ± 5000 yr is prominent in the speleothem record. The record correlates well with details and gross features of the GRIP ice core and confirms the time scale and the unstable climate proposed for substage 5e. The isotopic response in Termination II is delayed relative to the Devil's Hole record and is in accord with the SPECMAP chronology, but cooling at the end of substage 5e seems to be synchronous between Devil's Hole and the Norwegian flowstones.