Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland

• Published in: Boreas
• Main Authors: Souza, Priscila E., Sohbati, Reza, Murray, Andrew S., Clemmensen, Lars B., Kroon, Aart, Nielsen, Lars
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Greenland
• Online Access: https://curis.ku.dk/portal/da/publications/optical-dating-of-cobble-surfaces-determines-the-chronology-of-holocene-beach-ridges-in-greenland(f71b006e-221c-4f01-87ac-1189845a0f7b).html; https://doi.org/10.1111/bor.12507

We constrain the age of a cobble beach ridge system in Greenland using Optically Stimulated Luminescence (OSL) dating of buried cobble surfaces. Luminescence signals fromsix cobbles are measured using infrared (IR) stimulation at 50 degrees C(IR50) and 180 degrees C(pIRIR(180)); these cobbles represent four progressively younger beach ridges lying between similar to 35 and similar to 6 mabove present sea level. Luminescence-depth profiles show that the IR50 signals in all the samples and pIRIR(180) signals in four out of six samples are well bleached to depths >1.2 mminto the cobble surfaces. Equivalent doses in well-bleached cobble surface slices (i.e.