Journal
QUATERNARY GEOCHRONOLOGY
Volume 5, Issue 4, Pages 392-409Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.quageo.2009.12.001
Keywords
Be-10; Production rate; Cosmogenic nuclide; C-14; Moraine; Debris flow; Holocene; Last glacial maximum; South Island
Funding
- Gary C. Comer Science and Education Foundation (CSEF)
- National Oceanographic and Atmospheric Administration (NOAA)
- National Science Foundation [EAR-0745781, EAR-0345150]
- NOSAMS [OCE-0753487]
- Directorate For Geosciences
- Division Of Earth Sciences [0823521] Funding Source: National Science Foundation
- Division Of Earth Sciences
- Directorate For Geosciences [0823693] Funding Source: National Science Foundation
Ask authors/readers for more resources
We present a Be-10 production-rate calibration derived from an early Holocene debris-flow deposit at about 1000 m above sea level in the central Southern Alps, New Zealand, in the mid-latitude Southern Hemisphere. Ten radiocarbon ages on macrofossils from a soil horizon buried by the deposit date the deposit to 9690 +/- 50 calendar years before AD2008. Surface Be-10 concentrations of seven large boulders partially embedded in the stable surface of the deposit are tightly distributed, yielding a standard deviation of similar to 2%. Conversion of the Be-10 measurements to sea level/high-latitude values using each of five standard scaling methods indicates Be-10 production rates of 3.84 +/- 0.08, 3.87 +/- 0.08, 3.83 +/- 0.08, 4.15 +/- 0.09, and 3.74 +/- 0.08 atoms g(-1) a(-1), relative to the '07KNSTD' Be-10 AMS standard, and including only the local time-integrated production-rate uncertainties. When including a sea level high-latitude scaling uncertainty the overall error is similar to 2.5% (1 sigma) for each rate. To test the regional applicability of this production-rate calibration, we measured Be-10 concentrations in a set of nearby moraines deposited before 18060 +/- 200 years before AD2008. The Be-10 ages are only consistent with minimum-limiting C-14 age data when calculated using the new production rates. This also suggests that terrestrial in situ cosmogenic-nuclide production did not change significantly from Last Glacial Maximum to Holocene time in New Zealand. Our production rates agree well with those of a recent calibration study from northeastern North America, but are 12-14% lower than other commonly adopted values. The production-rate values presented here can be used elsewhere in New Zealand for rock surfaces exposed during or since the last glacial period. (C) 2009 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available