Macquarie Ridge Complex basalt 40Ar/39Ar geochronology data
40Ar/39Ar geochronology data of basalt samples from the Macquarie Ridge Complex (MRC). The MRC samples include basalts collected from Macquarie Island, the only exposed portion of the submarine Macquarie Ridge, by R. Merle and K. Evans during a field trip in November 2017, and dredge samples collect...
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Australian Antarctic Data Centre
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Online Access: | https://researchdata.edu.au/macquarie-ridge-complex-40ar39ar-geochronology/1432002 https://doi.org/10.26179/5d9fbfdea577b https://data.aad.gov.au/metadata/records/AAS_4444_MRC_Rock_Geochronology http://nla.gov.au/nla.party-617536 |
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ftands:oai:ands.org.au::1432002 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Research Data Australia (Australian National Data Service - ANDS) |
op_collection_id |
ftands |
language |
unknown |
topic |
geoscientificInformation IGNEOUS ROCKS EARTH SCIENCE SOLID EARTH ROCKS/MINERALS/CRYSTALS IGNEOUS ROCK AGE DETERMINATIONS MAJOR ELEMENTS ELEMENTS MINOR ELEMENTS BASALT THERMOFISHER© ARGUS VI MASS SPECTROMETER 40AR/39AR MASS SPECTROMETERS DREDGING DEVICES LABORATORY FIELD SURVEYS R/V TANGAROA GEOGRAPHIC REGION > POLAR OCEAN > SOUTHERN OCEAN |
spellingShingle |
geoscientificInformation IGNEOUS ROCKS EARTH SCIENCE SOLID EARTH ROCKS/MINERALS/CRYSTALS IGNEOUS ROCK AGE DETERMINATIONS MAJOR ELEMENTS ELEMENTS MINOR ELEMENTS BASALT THERMOFISHER© ARGUS VI MASS SPECTROMETER 40AR/39AR MASS SPECTROMETERS DREDGING DEVICES LABORATORY FIELD SURVEYS R/V TANGAROA GEOGRAPHIC REGION > POLAR OCEAN > SOUTHERN OCEAN Macquarie Ridge Complex basalt 40Ar/39Ar geochronology data |
topic_facet |
geoscientificInformation IGNEOUS ROCKS EARTH SCIENCE SOLID EARTH ROCKS/MINERALS/CRYSTALS IGNEOUS ROCK AGE DETERMINATIONS MAJOR ELEMENTS ELEMENTS MINOR ELEMENTS BASALT THERMOFISHER© ARGUS VI MASS SPECTROMETER 40AR/39AR MASS SPECTROMETERS DREDGING DEVICES LABORATORY FIELD SURVEYS R/V TANGAROA GEOGRAPHIC REGION > POLAR OCEAN > SOUTHERN OCEAN |
description |
40Ar/39Ar geochronology data of basalt samples from the Macquarie Ridge Complex (MRC). The MRC samples include basalts collected from Macquarie Island, the only exposed portion of the submarine Macquarie Ridge, by R. Merle and K. Evans during a field trip in November 2017, and dredge samples collected by the National Institute of Water and Atmospheric Research, New Zealand, during the TAN0803 voyage in 2008. Analytical methods of the 40Ar/39Ar geochronology data: Samples were crushed and minerals/groundmass were separated using a Frantz magnetic separator. Plagioclase, pyroxene, amphibole, sericite, and basaltic glass crystals and groundmass were separated from either the 125–212 μm or the 212–355 μm size fractions using a Frantz isodynamic magnetic separator. Minerals and groundmass were subsequently hand-picked grain-by-grain under a binocular stereomicroscope. Plagioclase and groundmass were further leached using diluted HF (2N) for 5 minutes and thoroughly rinsed in distilled water. Samples were loaded into several large wells of 1.9cm diameter and 0.3 cm depth aluminium discs. The discs were Cd-shielded to minimise undesirable nuclear interference re-actions and irradiated for 40 hours in the Oregon State University nuclear reactor (USA) in the central position. The samples were irradiated alongside FCs and GA1550 standards, for which ages of 28.294 ± 0.037 Ma and 99.738 ± 0.100 Ma were used, respectively. The 40Ar/39Ar analyses were performed at the Western Australian Argon Isotope Facility at Curtin University. The samples were step-heated using a continuous 100 W PhotonMachine© CO2 (IR, 10.4 µm) laser fired on the crystals during 60 seconds. Each of the standard crystals was fused in a single step. The gas was purified in an extra low-volume stainless steel extraction line of 240cc and using one SAES AP10 and one GP50 getter. Ar isotopes were measured in static mode using a low volume (600 cc) ARGUS VI mass spectrometer from Thermofisher© set with a permanent resolution of ~200. Measurements were carried out in multi-collection mode using four faradays to measure mass 40 to 37 and a 0-background compact discrete dynode ion counter to measure mass 36. We measured the relative abundance of each mass simultaneously using 10 cycles of peak-hopping and 33 seconds of integration time for each mass. Detectors were calibrated to each other electronically and using air shot beam signals. The raw data were processed using the ArArCALC software. The criteria for the determination of plateau are as follows: plateaus must include at least 70% of 39Ar released. The plateau should be distributed over a minimum of 3 consecutive steps agreeing at 95% confidence level and satisfying a probability of fit (P) of at least 0.05. Plateau ages are given at the 2σ level and are calculated using the mean of all the plateau steps, each weighted by the inverse variance of their individual analytical error. Uncertainties include analytical and J-value errors. |
author2 |
JIANG, QIANG (hasPrincipalInvestigator) JOURDAN, FRED (hasPrincipalInvestigator) MERLE, RENAUD (hasPrincipalInvestigator) OLIEROOK, HUGO (hasPrincipalInvestigator) Australian Antarctic Data Centre (publisher) |
format |
Dataset |
title |
Macquarie Ridge Complex basalt 40Ar/39Ar geochronology data |
title_short |
Macquarie Ridge Complex basalt 40Ar/39Ar geochronology data |
title_full |
Macquarie Ridge Complex basalt 40Ar/39Ar geochronology data |
title_fullStr |
Macquarie Ridge Complex basalt 40Ar/39Ar geochronology data |
title_full_unstemmed |
Macquarie Ridge Complex basalt 40Ar/39Ar geochronology data |
title_sort |
macquarie ridge complex basalt 40ar/39ar geochronology data |
publisher |
Australian Antarctic Data Centre |
url |
https://researchdata.edu.au/macquarie-ridge-complex-40ar39ar-geochronology/1432002 https://doi.org/10.26179/5d9fbfdea577b https://data.aad.gov.au/metadata/records/AAS_4444_MRC_Rock_Geochronology http://nla.gov.au/nla.party-617536 |
op_coverage |
Spatial: northlimit=-44.71551; southlimit=-60.32695; westlimit=156.00586; eastLimit=167.51953; projection=WGS84 Temporal: From 2017-07-01 to 2019-06-30 |
long_lat |
ENVELOPE(139.933,139.933,-66.679,-66.679) ENVELOPE(156.00586,167.51953,-44.71551,-60.32695) |
geographic |
Merle New Zealand Southern Ocean |
geographic_facet |
Merle New Zealand Southern Ocean |
genre |
Macquarie Island Southern Ocean |
genre_facet |
Macquarie Island Southern Ocean |
op_source |
Australian Antarctic Data Centre |
op_relation |
https://researchdata.edu.au/macquarie-ridge-complex-40ar39ar-geochronology/1432002 7d9cb0c1-64e5-4a70-8ad9-1814a905bf41 doi:10.26179/5d9fbfdea577b AAS_4444_MRC_Rock_Geochronology https://data.aad.gov.au/metadata/records/AAS_4444_MRC_Rock_Geochronology http://nla.gov.au/nla.party-617536 |
op_doi |
https://doi.org/10.26179/5d9fbfdea577b |
_version_ |
1766066387363561472 |
spelling |
ftands:oai:ands.org.au::1432002 2023-05-15T17:10:00+02:00 Macquarie Ridge Complex basalt 40Ar/39Ar geochronology data JIANG, QIANG (hasPrincipalInvestigator) JOURDAN, FRED (hasPrincipalInvestigator) MERLE, RENAUD (hasPrincipalInvestigator) OLIEROOK, HUGO (hasPrincipalInvestigator) Australian Antarctic Data Centre (publisher) Spatial: northlimit=-44.71551; southlimit=-60.32695; westlimit=156.00586; eastLimit=167.51953; projection=WGS84 Temporal: From 2017-07-01 to 2019-06-30 https://researchdata.edu.au/macquarie-ridge-complex-40ar39ar-geochronology/1432002 https://doi.org/10.26179/5d9fbfdea577b https://data.aad.gov.au/metadata/records/AAS_4444_MRC_Rock_Geochronology http://nla.gov.au/nla.party-617536 unknown Australian Antarctic Data Centre https://researchdata.edu.au/macquarie-ridge-complex-40ar39ar-geochronology/1432002 7d9cb0c1-64e5-4a70-8ad9-1814a905bf41 doi:10.26179/5d9fbfdea577b AAS_4444_MRC_Rock_Geochronology https://data.aad.gov.au/metadata/records/AAS_4444_MRC_Rock_Geochronology http://nla.gov.au/nla.party-617536 Australian Antarctic Data Centre geoscientificInformation IGNEOUS ROCKS EARTH SCIENCE SOLID EARTH ROCKS/MINERALS/CRYSTALS IGNEOUS ROCK AGE DETERMINATIONS MAJOR ELEMENTS ELEMENTS MINOR ELEMENTS BASALT THERMOFISHER© ARGUS VI MASS SPECTROMETER 40AR/39AR MASS SPECTROMETERS DREDGING DEVICES LABORATORY FIELD SURVEYS R/V TANGAROA GEOGRAPHIC REGION > POLAR OCEAN > SOUTHERN OCEAN dataset ftands https://doi.org/10.26179/5d9fbfdea577b 2020-12-21T23:21:19Z 40Ar/39Ar geochronology data of basalt samples from the Macquarie Ridge Complex (MRC). The MRC samples include basalts collected from Macquarie Island, the only exposed portion of the submarine Macquarie Ridge, by R. Merle and K. Evans during a field trip in November 2017, and dredge samples collected by the National Institute of Water and Atmospheric Research, New Zealand, during the TAN0803 voyage in 2008. Analytical methods of the 40Ar/39Ar geochronology data: Samples were crushed and minerals/groundmass were separated using a Frantz magnetic separator. Plagioclase, pyroxene, amphibole, sericite, and basaltic glass crystals and groundmass were separated from either the 125–212 μm or the 212–355 μm size fractions using a Frantz isodynamic magnetic separator. Minerals and groundmass were subsequently hand-picked grain-by-grain under a binocular stereomicroscope. Plagioclase and groundmass were further leached using diluted HF (2N) for 5 minutes and thoroughly rinsed in distilled water. Samples were loaded into several large wells of 1.9cm diameter and 0.3 cm depth aluminium discs. The discs were Cd-shielded to minimise undesirable nuclear interference re-actions and irradiated for 40 hours in the Oregon State University nuclear reactor (USA) in the central position. The samples were irradiated alongside FCs and GA1550 standards, for which ages of 28.294 ± 0.037 Ma and 99.738 ± 0.100 Ma were used, respectively. The 40Ar/39Ar analyses were performed at the Western Australian Argon Isotope Facility at Curtin University. The samples were step-heated using a continuous 100 W PhotonMachine© CO2 (IR, 10.4 µm) laser fired on the crystals during 60 seconds. Each of the standard crystals was fused in a single step. The gas was purified in an extra low-volume stainless steel extraction line of 240cc and using one SAES AP10 and one GP50 getter. Ar isotopes were measured in static mode using a low volume (600 cc) ARGUS VI mass spectrometer from Thermofisher© set with a permanent resolution of ~200. Measurements were carried out in multi-collection mode using four faradays to measure mass 40 to 37 and a 0-background compact discrete dynode ion counter to measure mass 36. We measured the relative abundance of each mass simultaneously using 10 cycles of peak-hopping and 33 seconds of integration time for each mass. Detectors were calibrated to each other electronically and using air shot beam signals. The raw data were processed using the ArArCALC software. The criteria for the determination of plateau are as follows: plateaus must include at least 70% of 39Ar released. The plateau should be distributed over a minimum of 3 consecutive steps agreeing at 95% confidence level and satisfying a probability of fit (P) of at least 0.05. Plateau ages are given at the 2σ level and are calculated using the mean of all the plateau steps, each weighted by the inverse variance of their individual analytical error. Uncertainties include analytical and J-value errors. Dataset Macquarie Island Southern Ocean Research Data Australia (Australian National Data Service - ANDS) Merle ENVELOPE(139.933,139.933,-66.679,-66.679) New Zealand Southern Ocean ENVELOPE(156.00586,167.51953,-44.71551,-60.32695) |