A reappraisal of low-temperature thermochronology of the eastern Fennoscandia Shield and radiation-enhanced apatite fission-track annealing

Abstract

We assess the proposal of Hendriks & Redfield (Earth and Planetary Science Letters, 236, 443-458, 2005) that cross-over of the predicted apatite fission track (AFT) > (U-Th-Sm)/He (AHe) age relationship in the southeastern Fennoscandian shield in southern Finland reflects α-radiation-enhanced annealing (REA) of fission tracks at low temperatures and that more robust estimates of the denudation history are recorded through reproducible AHe data. New AHe results from southern Finland showing variable dispersion of single-grain ages may be biased by different factors operating within grains, which tend to give a greater weighting towards older age outliers. AHe ages from mafic rocks show the le..