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The deep accumulation of 10 Be at Utsira, southwestern Norway: Implications for cosmogenic nuclide exposure dating in peripheral ice sheet landscapes
Author(s) -
Briner Jason P.,
Goehring Brent M.,
Mangerud Jan,
Svendsen John Inge
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl070100
Subject(s) - cosmogenic nuclide , surface exposure dating , deglaciation , geology , chronology , ice sheet , glacial period , bedrock , moraine , physical geography , ice age , ice core , paleontology , geomorphology , oceanography , cosmic ray , geography , physics , astrophysics
Cosmogenic nuclide exposure dating is a widely used method for constraining past ice sheet histories. We scrutinize a recently published data set of cosmogenic 10 Be data from erratic boulders in Norway used to constrain the deglaciation of the western Scandinavian Ice Sheet to 20 ka. Our model of the 10 Be inventory in glacial surfaces leads us to conclude that the chronology may be afflicted by the deep subsurface accumulation of 10 Be during long‐lasting ice‐free periods that resulted in 10 Be ages >10% too old. We suggest that the majority of the dated erratic boulders contain a uniform level of inherited muon‐produced 10 Be and were derived from bedrock depths >2.5 m and most likely ~4 m. The implication of our finding is that for landscapes that experience long ice‐free periods between brief maximum glacial phases, glacial erosion of >5 m is required to remove detectable traces of inherited 10 Be.