Geochronology of Hadean zircon grains from the Jack Hills, Western Australia constrained by quantitative scanning ion imaging
Five Hadean (> 4 Ga) aged zircon grains from the Jack Hills metasedimentary belt have been investigated by a secondary ion mass spectrometry scanning ion image technique. This technique has the ability to obtain accurate and precise full U-Pb systematics on a scale < 5 µm, as well as doc...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
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Elsevier Science BV
2018
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| Online Access: | http://hdl.handle.net/20.500.11937/61132 |
| _version_ | 1848760661112258560 |
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| author | Bellucci, J. Nemchin, Alexander Whitehouse, M. Kielman, R. Snape, J. Pidgeon, Robert |
| author_facet | Bellucci, J. Nemchin, Alexander Whitehouse, M. Kielman, R. Snape, J. Pidgeon, Robert |
| author_sort | Bellucci, J. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Five Hadean (> 4 Ga) aged zircon grains from the Jack Hills metasedimentary belt have been investigated by a secondary ion mass spectrometry scanning ion image technique. This technique has the ability to obtain accurate and precise full U-Pb systematics on a scale < 5 µm, as well as document the spatial distribution of U, Th and Pb. All five of the grains investigated here have complex cathodoluminescence patterns that correlate to different U, Th, and Pb concentration domains. The age determinations for these different chemical zones indicate multiple reworking events that are preserved in each grain and have affected the primary crystalized zircon on the scale of < 10 µm, smaller than conventional ion microprobe spot analyses. In comparison to the spot analyses performed on these grains, these new scanning ion images and age determinations indicate that almost half of the spot analyses have intersected several age and chemical domains in both fractured and unfractured parts of the individual crystals. Some of these unfractured, mixed domain spot analyses have concordant ages that are inaccurate. Thus, if the frequency of spot analyses intersecting mixed domains here is even close to representative of all other studies of the Jack Hills zircon population, it makes the interpretation of any trace element, Hf, or O isotopic data present in the literature tenuous. Lastly, all of the grains analysed here preserve at least two distinguishable 207 Pb/ 206 Pb ages. These ages are preserved in core-rim and/or complex internal textural relationships in unfractured domains. These secondary events took place at ca. 4.3, 4.2, 4.1, 4.0, 3.7, and 2.9 Ga, which are coincident with previously determined statistically robust age peaks present in this zircon population. |
| first_indexed | 2025-11-14T10:19:19Z |
| format | Journal Article |
| id | curtin-20.500.11937-61132 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:19:19Z |
| publishDate | 2018 |
| publisher | Elsevier Science BV |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-611322018-07-03T03:15:42Z Geochronology of Hadean zircon grains from the Jack Hills, Western Australia constrained by quantitative scanning ion imaging Bellucci, J. Nemchin, Alexander Whitehouse, M. Kielman, R. Snape, J. Pidgeon, Robert Five Hadean (> 4 Ga) aged zircon grains from the Jack Hills metasedimentary belt have been investigated by a secondary ion mass spectrometry scanning ion image technique. This technique has the ability to obtain accurate and precise full U-Pb systematics on a scale < 5 µm, as well as document the spatial distribution of U, Th and Pb. All five of the grains investigated here have complex cathodoluminescence patterns that correlate to different U, Th, and Pb concentration domains. The age determinations for these different chemical zones indicate multiple reworking events that are preserved in each grain and have affected the primary crystalized zircon on the scale of < 10 µm, smaller than conventional ion microprobe spot analyses. In comparison to the spot analyses performed on these grains, these new scanning ion images and age determinations indicate that almost half of the spot analyses have intersected several age and chemical domains in both fractured and unfractured parts of the individual crystals. Some of these unfractured, mixed domain spot analyses have concordant ages that are inaccurate. Thus, if the frequency of spot analyses intersecting mixed domains here is even close to representative of all other studies of the Jack Hills zircon population, it makes the interpretation of any trace element, Hf, or O isotopic data present in the literature tenuous. Lastly, all of the grains analysed here preserve at least two distinguishable 207 Pb/ 206 Pb ages. These ages are preserved in core-rim and/or complex internal textural relationships in unfractured domains. These secondary events took place at ca. 4.3, 4.2, 4.1, 4.0, 3.7, and 2.9 Ga, which are coincident with previously determined statistically robust age peaks present in this zircon population. 2018 Journal Article http://hdl.handle.net/20.500.11937/61132 10.1016/j.chemgeo.2017.11.042 Elsevier Science BV restricted |
| spellingShingle | Bellucci, J. Nemchin, Alexander Whitehouse, M. Kielman, R. Snape, J. Pidgeon, Robert Geochronology of Hadean zircon grains from the Jack Hills, Western Australia constrained by quantitative scanning ion imaging |
| title | Geochronology of Hadean zircon grains from the Jack Hills, Western Australia constrained by quantitative scanning ion imaging |
| title_full | Geochronology of Hadean zircon grains from the Jack Hills, Western Australia constrained by quantitative scanning ion imaging |
| title_fullStr | Geochronology of Hadean zircon grains from the Jack Hills, Western Australia constrained by quantitative scanning ion imaging |
| title_full_unstemmed | Geochronology of Hadean zircon grains from the Jack Hills, Western Australia constrained by quantitative scanning ion imaging |
| title_short | Geochronology of Hadean zircon grains from the Jack Hills, Western Australia constrained by quantitative scanning ion imaging |
| title_sort | geochronology of hadean zircon grains from the jack hills, western australia constrained by quantitative scanning ion imaging |
| url | http://hdl.handle.net/20.500.11937/61132 |