Origin and Be-10 surface exposure dating of a coarse debris accumulation in the Hruby Jesenik Mountains, Central Europe
Abstract
Coarse debris accumulations cover large areas in high latitude and mountain environments, but their age and origin remain mostly unknown. Here we reassess the morphology of a prominent coarse debris accumulation in the Sudetes Mountain range in central Europe and constrain its timing with Be-10 surface exposure data.
Our observations indicate that the landform in the south-eastern slope of the Sut ridge appears consistent with the morphology of a block slope. The oldest minimum age of 150.1 +/- 4.8 ka obtained for the tor at the upper limit of the block slope indicates the disintegration of the ridge and surface lowering under periglacial conditions prior to the last glacial-interglacial cycle.
Four exposure ages retrieved for block samples range from 84.3 +/- 3.8 to 26.8 +/- 2.6 ka, providing evidence for block emplacement during the last cold period. The exposure ages extend existing chronological dataset for peri/glacial landforms in the Sudetes and constrain the timing of cold environments in the area prior the Last Glacial Maximum.
The ages are also consistent with surface exposure data reported for block fields and block slopes in Western Europe and confirm the formation of similar landforms over the last glacial period in the Sudetes. (C) 2020 Elsevier B.V. All rights reserved.