Details

Autor(en) / Beteiligte

• Corbett, Lee B
• Bierman, Paul R
• Rood, Dylan H
• Caffee, Marc W
• Lifton, Nathaniel A
• Woodruff, Thomas E

Titel

Cosmogenic super(26)Al/ super(10)Be surface production ratio in Greenland

Ist Teil von

• Geophysical research letters, 2017-02, Vol.44 (3), p.1350-1359

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• The assumed value for the cosmogenic super(26)Al/ super(10)Be surface production rate ratio in quartz is an important parameter for studies investigating the burial or subaerial erosion of long-lived surfaces and sediments. Recent models and data suggest that the production ratio is spatially variable and may be greater than originally thought. Here we present measured super(26)Al/ super(10)Be ratios for 24 continuously exposed bedrock and boulder surfaces spanning ~61-77 degree N in Greenland. Empirical measurements, such as ours, include nuclides produced predominately by neutron-induced spallation with percent-level contributions by muon interactions. The slope of a York regression line fit to our data is 7.3 plus or minus 0.3 (1 sigma ), suggesting that the super(26)Al/ super(10)Be surface production ratio exceeds the commonly used value of 6.75, at least in the Arctic. A higher super(26)Al/ super(10)Be production ratio has implications for multinuclide cosmogenic isotope studies because it results in greater modeled burial durations and erosion rates. Key Points * The cosmogenic super(26)Al/ super(10)Be production ratio in quartz is higher than traditionally thought and likely varies with latitude/altitude * Using continually exposed rock surfaces in Greenland, we constrain the high-latitude super(26)Al/ super(10)Be production ratio to 7.3 plus or minus 0.3 * A higher assumed super(26)Al/ super(10)Be production ratio results in greater modeled burial durations and erosion rates