Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~ 15 ka

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F19%3A10398702" target="_blank" >RIV/00216208:11310/19:10398702 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=RZvKTLmbEr" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=RZvKTLmbEr</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1017/qua.2019.10" target="_blank" >10.1017/qua.2019.10</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~ 15 ka

Popis výsledku v původním jazyce

The Foothills Erratics Train consists of large quartzite blocks of Rocky Mountains origin deposited on the eastern slopes of the Rocky Mountain Foothills in Alberta between ~53.5°N and 49°N. The blocks were deposited in their present locations when the western margin of the Laurentide Ice Sheet (LIS) detached from the local ice masses of the Rocky Mountains, which initiated the opening of the southern end of the ice-free corridor between the Cordilleran Ice Sheet and the LIS. We use 10Be exposure dating to constrain the beginning of this decoupling. Based on a group of 12 samples well-clustered in time, we date the detachment of the western LIS margin from the Rocky Mountain front to ~14.9 +- 0.9 ka. This is ~1000 years later than previously assumed, but a lack of a latitudinal trend in the ages over a distance of ~500 km is consistent with the rapid opening of a long wedge of unglaciated terrain portrayed in existing ice-retreat reconstructions. A later separation of the western LIS margin from the mountain front implies higher ice margin-retreat rates in order to meet the Younger Dryas ice margin position near the boundary of the Canadian Shield ~2000 years later.

Název v anglickém jazyce

Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~ 15 ka

Popis výsledku anglicky

The Foothills Erratics Train consists of large quartzite blocks of Rocky Mountains origin deposited on the eastern slopes of the Rocky Mountain Foothills in Alberta between ~53.5°N and 49°N. The blocks were deposited in their present locations when the western margin of the Laurentide Ice Sheet (LIS) detached from the local ice masses of the Rocky Mountains, which initiated the opening of the southern end of the ice-free corridor between the Cordilleran Ice Sheet and the LIS. We use 10Be exposure dating to constrain the beginning of this decoupling. Based on a group of 12 samples well-clustered in time, we date the detachment of the western LIS margin from the Rocky Mountain front to ~14.9 +- 0.9 ka. This is ~1000 years later than previously assumed, but a lack of a latitudinal trend in the ages over a distance of ~500 km is consistent with the rapid opening of a long wedge of unglaciated terrain portrayed in existing ice-retreat reconstructions. A later separation of the western LIS margin from the mountain front implies higher ice margin-retreat rates in order to meet the Younger Dryas ice margin position near the boundary of the Canadian Shield ~2000 years later.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10508 - Physical geography

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Quaternary Research

ISSN

0033-5894

e-ISSN

—

Svazek periodika

92

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

469-482

Kód UT WoS článku

000487316500014

EID výsledku v databázi Scopus

2-s2.0-85068998587