Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating
Beryllium-10 (10Be) in quartz represents the most common in situ cosmogenic nuclide used for quantifying Earth-surface processes, primarily due to the prevalence of quartz in the Earth's crust. However many landscapes lack quartz-bearing rocks, thus other nuclide-mineral pairs are required for...
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/202780 2024-01-14T10:02:20+01:00 Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating Eaves, Shaun Collins, Julia Jones, R. Selwyn Norton, Kevin Tims, Stephen Mackintosh, A N application/pdf http://hdl.handle.net/1885/202780 https://doi.org/10.1016/j.quageo.2018.09.006 https://openresearch-repository.anu.edu.au/bitstream/1885/202780/5/01_Eaves_Further_constraint_of_the_in_2018.pdf.jpg en_AU eng Elsevier 1871-1014 http://hdl.handle.net/1885/202780 doi:10.1016/j.quageo.2018.09.006 https://openresearch-repository.anu.edu.au/bitstream/1885/202780/5/01_Eaves_Further_constraint_of_the_in_2018.pdf.jpg © 2018 Elsevier B.V. Quaternary Geochronology Journal article ftanucanberra https://doi.org/10.1016/j.quageo.2018.09.006 2023-12-15T09:36:18Z Beryllium-10 (10Be) in quartz represents the most common in situ cosmogenic nuclide used for quantifying Earth-surface processes, primarily due to the prevalence of quartz in the Earth's crust. However many landscapes lack quartz-bearing rocks, thus other nuclide-mineral pairs are required for geochronometric and geomorphic applications. Here we describe the successful isolation and measurement of in situ10Be concentrations in pyroxene from two mafic sample sets: (i) andesite boulders of the Murimotu Formation debris avalanche on Mt. Ruapehu, New Zealand, and (ii) dolerite cobbles deposited in a ∼100 m vertical transect at Mt. Gran by Mackay Glacier, Antarctica. Precise radiocarbon age constraint of the New Zealand site provides further geological constraint of the reference (at sea level and high latitude) 10Be production rate in pyroxene, which we find to be indistinguishable from a previous estimate. Combining our results with previous data yields a reference production rate of 3.2 ± 0.8 at. g−1 yr−1 (n=5; ‘Lm’ scaling). Application of this rate to the glacial cobbles at Mackay Glacier yields a relatively coherent chronology of ice surface lowering between ∼14 and 6 ka, which is broadly consistent with a well-constrained quartz-based 10Be chronology from nearby nunataks. Improving the viability of in situ10Be for geological applications in mafic domains requires increased analytical precision beyond current levels. This improvement may be best achieved by further modification of the quartz-based methodologies for 10Be purification, in order to better handle the high cationic contaminant loads of ferromagnesian minerals. In addition, further 10Be measurements from suitable mafic sedimentary deposits with independent age control (e.g. existing cosmogenic 3He calibration sites) will help to refine estimates of the reference production rate. This research was funded by a University Research Fund grant awarded to KPN and ANM by Victoria University of Wellington. Article in Journal/Newspaper Antarc* Antarctica Australian National University: ANU Digital Collections New Zealand Handle The ENVELOPE(161.983,161.983,-78.000,-78.000) Mackay ENVELOPE(168.517,168.517,-77.700,-77.700) Mackay Glacier ENVELOPE(162.000,162.000,-76.967,-76.967) Quaternary Geochronology 48 121 132 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
English |
description |
Beryllium-10 (10Be) in quartz represents the most common in situ cosmogenic nuclide used for quantifying Earth-surface processes, primarily due to the prevalence of quartz in the Earth's crust. However many landscapes lack quartz-bearing rocks, thus other nuclide-mineral pairs are required for geochronometric and geomorphic applications. Here we describe the successful isolation and measurement of in situ10Be concentrations in pyroxene from two mafic sample sets: (i) andesite boulders of the Murimotu Formation debris avalanche on Mt. Ruapehu, New Zealand, and (ii) dolerite cobbles deposited in a ∼100 m vertical transect at Mt. Gran by Mackay Glacier, Antarctica. Precise radiocarbon age constraint of the New Zealand site provides further geological constraint of the reference (at sea level and high latitude) 10Be production rate in pyroxene, which we find to be indistinguishable from a previous estimate. Combining our results with previous data yields a reference production rate of 3.2 ± 0.8 at. g−1 yr−1 (n=5; ‘Lm’ scaling). Application of this rate to the glacial cobbles at Mackay Glacier yields a relatively coherent chronology of ice surface lowering between ∼14 and 6 ka, which is broadly consistent with a well-constrained quartz-based 10Be chronology from nearby nunataks. Improving the viability of in situ10Be for geological applications in mafic domains requires increased analytical precision beyond current levels. This improvement may be best achieved by further modification of the quartz-based methodologies for 10Be purification, in order to better handle the high cationic contaminant loads of ferromagnesian minerals. In addition, further 10Be measurements from suitable mafic sedimentary deposits with independent age control (e.g. existing cosmogenic 3He calibration sites) will help to refine estimates of the reference production rate. This research was funded by a University Research Fund grant awarded to KPN and ANM by Victoria University of Wellington. |
format |
Article in Journal/Newspaper |
author |
Eaves, Shaun Collins, Julia Jones, R. Selwyn Norton, Kevin Tims, Stephen Mackintosh, A N |
spellingShingle |
Eaves, Shaun Collins, Julia Jones, R. Selwyn Norton, Kevin Tims, Stephen Mackintosh, A N Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating |
author_facet |
Eaves, Shaun Collins, Julia Jones, R. Selwyn Norton, Kevin Tims, Stephen Mackintosh, A N |
author_sort |
Eaves, Shaun |
title |
Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating |
title_short |
Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating |
title_full |
Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating |
title_fullStr |
Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating |
title_full_unstemmed |
Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating |
title_sort |
further constraint of the in situ cosmogenic 10be production rate in pyroxene and a viability test for late quaternary exposure dating |
publisher |
Elsevier |
url |
http://hdl.handle.net/1885/202780 https://doi.org/10.1016/j.quageo.2018.09.006 https://openresearch-repository.anu.edu.au/bitstream/1885/202780/5/01_Eaves_Further_constraint_of_the_in_2018.pdf.jpg |
long_lat |
ENVELOPE(161.983,161.983,-78.000,-78.000) ENVELOPE(168.517,168.517,-77.700,-77.700) ENVELOPE(162.000,162.000,-76.967,-76.967) |
geographic |
New Zealand Handle The Mackay Mackay Glacier |
geographic_facet |
New Zealand Handle The Mackay Mackay Glacier |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Quaternary Geochronology |
op_relation |
1871-1014 http://hdl.handle.net/1885/202780 doi:10.1016/j.quageo.2018.09.006 https://openresearch-repository.anu.edu.au/bitstream/1885/202780/5/01_Eaves_Further_constraint_of_the_in_2018.pdf.jpg |
op_rights |
© 2018 Elsevier B.V. |
op_doi |
https://doi.org/10.1016/j.quageo.2018.09.006 |
container_title |
Quaternary Geochronology |
container_volume |
48 |
container_start_page |
121 |
op_container_end_page |
132 |
_version_ |
1788057304265916416 |