Luminescence analysis of a postglacial landscape in northeastern Norway and northern Finland

Abstract

Portable optically stimulated luminescence (pOSL) analysis allows rapid relative dating of sediments that potentially can be calibrated against known OSL ages to provide an age estimate for landforms across a large area. This study uses 186 pOSL measurements and 20 OSL ages to investigate the postglacial landscape evolution inside the Younger Dryas moraines in NE Finnmark and Finnish Lapland. Aeolian sediments are widespread in the study area, with activity initiating in Finnmark around 10.2 ka. Increases in aeolian activity and dune formation occur from 6.5 ka across the study area, with a peak in the last 1500 years. Glacial sediments and landforms provided more challenging targets for both OSL and pOSL analyses and dating, but properties determined from pOSL proxy data show potential for determining sediment history of mobilization and deposition. Calibration of pOSL data against OSL age estimates, a developing method of luminescence dating, lets us build a chronology of activity from a larger data set, and in a much less time- and cost-consuming way than using only OSL would allow.