Constraints from cosmogenic nuclides on the glaciation and erosion history of Dove Bugt, northeast Greenland

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F20%3A00531376" target="_blank" >RIV/67985530:_____/20:00531376 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.geoscienceworld.org/gsa/gsabulletin/article/132/11-12/2282/583151/Constraints-from-cosmogenic-nuclides-on-the" target="_blank" >https://pubs.geoscienceworld.org/gsa/gsabulletin/article/132/11-12/2282/583151/Constraints-from-cosmogenic-nuclides-on-the</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1130/B35410.1" target="_blank" >10.1130/B35410.1</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Constraints from cosmogenic nuclides on the glaciation and erosion history of Dove Bugt, northeast Greenland

Popis výsledku v původním jazyce

The intricate interplay between subglacial topography and ice-sheet dynamics is key to the evolution of large ice sheets, but in Greenland as elsewhere the effects of long-term glacial history on landscape evolution remain poorly constrained. Here we measure abundances of cosmogenic Be-10 and Al-26 in bedrock and transported boulders to unveil the glaciation and erosion history of Dove Bugt, northeast Greenland. In agreement with studies of west Greenland, we find that apparent exposure ages increase with elevation from 9 ka to 13 ka in low-lying valleys to 21 ka to 204 ka on high-elevation, blockfield-covered plateaus. We employ a Markov chain Monte Carlo inversion framework to constrain the probability of various erosion histories, and we quantify the residence time of samples within the upper 2 m of the bedrock subsurface-a measure defined as the cosmogenic nuclide memory. This cosmogenic nuclide memory exceeds 600 ka on the highest plateaus but is limited to less than 500 ka in most other high-elevation samples and to less than 100 ka at low-elevations. Our results define maximum limits for the fraction of ice cover during the past 1 Ma to -70% on the Store Koldewey peaks and --90% farther inland at Pusterdal, respectively. Minimum limits to ice cover, however, cannot be reliably constrained by the data. Finally, we propose that limited erosion on the highest plateaus of Store Koldewey since 0.6-1.0 Ma indicates a minimum age for fjord-plateau formation within this area of northeast Greenland.

Název v anglickém jazyce

Constraints from cosmogenic nuclides on the glaciation and erosion history of Dove Bugt, northeast Greenland

Popis výsledku anglicky

The intricate interplay between subglacial topography and ice-sheet dynamics is key to the evolution of large ice sheets, but in Greenland as elsewhere the effects of long-term glacial history on landscape evolution remain poorly constrained. Here we measure abundances of cosmogenic Be-10 and Al-26 in bedrock and transported boulders to unveil the glaciation and erosion history of Dove Bugt, northeast Greenland. In agreement with studies of west Greenland, we find that apparent exposure ages increase with elevation from 9 ka to 13 ka in low-lying valleys to 21 ka to 204 ka on high-elevation, blockfield-covered plateaus. We employ a Markov chain Monte Carlo inversion framework to constrain the probability of various erosion histories, and we quantify the residence time of samples within the upper 2 m of the bedrock subsurface-a measure defined as the cosmogenic nuclide memory. This cosmogenic nuclide memory exceeds 600 ka on the highest plateaus but is limited to less than 500 ka in most other high-elevation samples and to less than 100 ka at low-elevations. Our results define maximum limits for the fraction of ice cover during the past 1 Ma to -70% on the Store Koldewey peaks and --90% farther inland at Pusterdal, respectively. Minimum limits to ice cover, however, cannot be reliably constrained by the data. Finally, we propose that limited erosion on the highest plateaus of Store Koldewey since 0.6-1.0 Ma indicates a minimum age for fjord-plateau formation within this area of northeast Greenland.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Geological Society of America Bulletin

ISSN

0016-7606

e-ISSN

—

Svazek periodika

132

Číslo periodika v rámci svazku

11/12

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

2282-2294

Kód UT WoS článku

000588959000004

EID výsledku v databázi Scopus

2-s2.0-85095608918