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Title: Directly dating postglacial Greenlandic land-surface emergence at high resolution using in situ 10 Be
Abstract Postglacial emergence curves are used to infer mantle rheology, delimit ice extent, and test models of the solid Earth response to changing ice and water loads. Such curves are rarely produced by direct dating of land emergence; rather, most rely on the presence of radiocarbon-datable organic material and inferences made between the age of sedimentary deposits and landforms indicative of former sea level. Here, we demonstrate a new approach,10Be dating, to determine rates of postglacial land emergence in two different settings. In southern Greenland (Narsarsuaq/Igaliku), we date directly the exposure, as relative sea level fell, of gravel beaches and rocky outcrops allowing determination of rapid, post–Younger Dryas emergence. In western Greenland (Kangerlussuaq), we constrain Holocene isostatic response by dating the sequential stripping of terrace sediment driven by land-surface uplift, relative sea-level fall, and resulting fluvial incision. The technique we employ provides high temporal and elevation resolution important for quantifying rapid emergence immediately after deglaciation and less rapid uplift during the middle Holocene.10Be-constrained emergence curves can improve knowledge of relative sea-level change by dating land emergence along rocky coasts, at elevations and locations where radiocarbon-datable sediments are not present, and without the lag time needed for organic material to accumulate.  more » « less
Award ID(s):
1735676
PAR ID:
10490178
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
Quaternary Researach
Date Published:
Journal Name:
Quaternary Research
Volume:
90
Issue:
1
ISSN:
0033-5894
Page Range / eLocation ID:
110 to 126
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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