Dating deposition and low-grade metamorphism by in situ U-Pb geochronology of titanite in the Paleoproterozoic Timeball Hill Formation, southern Africa
Titanite coexists with zircon in a felsic tuff in the Paleoproterozoic Timeball Hill Formation, southern Africa. Two generations of titanite are preserved: euhedral, brown crystals with apatite inclusions, and colorless, matrix-filling cement. The brown titanite has elevated U, Th and Fe, and low Al...
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| Format: | Journal Article |
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Elsevier Science BV
2013
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| Online Access: | http://hdl.handle.net/20.500.11937/22987 |
| _version_ | 1848751026107056128 |
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| author | Rasmussen, Birger Fletcher, Ian Muhling, J. |
| author_facet | Rasmussen, Birger Fletcher, Ian Muhling, J. |
| author_sort | Rasmussen, Birger |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Titanite coexists with zircon in a felsic tuff in the Paleoproterozoic Timeball Hill Formation, southern Africa. Two generations of titanite are preserved: euhedral, brown crystals with apatite inclusions, and colorless, matrix-filling cement. The brown titanite has elevated U, Th and Fe, and low Al, consistent with a magmatic origin, whereas the colorless titanite has higher Al and F contents, suggestive of a metamorphic paragenesis. In situ SHRIMP geochronology of zircons extracted from a polished thin section of the tuff bed suffer from inheritance and Pb--loss and yield an imprecise date (2259 ± 35 Ma), whereas coexisting brown titanites give a weighted mean 207Pb/206Pb age of 2278 ± 7 Ma. This date is consistent with U--Pb zircon ages for tuffs in the same stratigraphic unit from a nearby drill-hole. The brown titanite is interpreted to be magmatic and to provide a reliable estimate for the age of deposition. In situ U--Pb dating of matrix-filling titanite cement from the same stratigraphic interval yields an age of 2145 ± 12 Ma, which corresponds with previous estimates for a low-grade tectonothermal event in southern Africa. Our results demonstrate that titanite is a versatile chronometer that can be used to constrain depositional ages, and those of low-grade metamorphism, thus increasing the number of sedimentary rocks that can be dated and elucidating the low-temperature geological history of depositional basins. |
| first_indexed | 2025-11-14T07:46:10Z |
| format | Journal Article |
| id | curtin-20.500.11937-22987 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:46:10Z |
| publishDate | 2013 |
| publisher | Elsevier Science BV |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-229872017-09-13T13:57:02Z Dating deposition and low-grade metamorphism by in situ U-Pb geochronology of titanite in the Paleoproterozoic Timeball Hill Formation, southern Africa Rasmussen, Birger Fletcher, Ian Muhling, J. SHRIMP Stratigraphy Tuff Zircon U--Pb geochronology Titanite Titanite coexists with zircon in a felsic tuff in the Paleoproterozoic Timeball Hill Formation, southern Africa. Two generations of titanite are preserved: euhedral, brown crystals with apatite inclusions, and colorless, matrix-filling cement. The brown titanite has elevated U, Th and Fe, and low Al, consistent with a magmatic origin, whereas the colorless titanite has higher Al and F contents, suggestive of a metamorphic paragenesis. In situ SHRIMP geochronology of zircons extracted from a polished thin section of the tuff bed suffer from inheritance and Pb--loss and yield an imprecise date (2259 ± 35 Ma), whereas coexisting brown titanites give a weighted mean 207Pb/206Pb age of 2278 ± 7 Ma. This date is consistent with U--Pb zircon ages for tuffs in the same stratigraphic unit from a nearby drill-hole. The brown titanite is interpreted to be magmatic and to provide a reliable estimate for the age of deposition. In situ U--Pb dating of matrix-filling titanite cement from the same stratigraphic interval yields an age of 2145 ± 12 Ma, which corresponds with previous estimates for a low-grade tectonothermal event in southern Africa. Our results demonstrate that titanite is a versatile chronometer that can be used to constrain depositional ages, and those of low-grade metamorphism, thus increasing the number of sedimentary rocks that can be dated and elucidating the low-temperature geological history of depositional basins. 2013 Journal Article http://hdl.handle.net/20.500.11937/22987 10.1016/j.chemgeo.2013.04.015 Elsevier Science BV restricted |
| spellingShingle | SHRIMP Stratigraphy Tuff Zircon U--Pb geochronology Titanite Rasmussen, Birger Fletcher, Ian Muhling, J. Dating deposition and low-grade metamorphism by in situ U-Pb geochronology of titanite in the Paleoproterozoic Timeball Hill Formation, southern Africa |
| title | Dating deposition and low-grade metamorphism by in situ U-Pb geochronology of titanite in the Paleoproterozoic Timeball Hill Formation, southern Africa |
| title_full | Dating deposition and low-grade metamorphism by in situ U-Pb geochronology of titanite in the Paleoproterozoic Timeball Hill Formation, southern Africa |
| title_fullStr | Dating deposition and low-grade metamorphism by in situ U-Pb geochronology of titanite in the Paleoproterozoic Timeball Hill Formation, southern Africa |
| title_full_unstemmed | Dating deposition and low-grade metamorphism by in situ U-Pb geochronology of titanite in the Paleoproterozoic Timeball Hill Formation, southern Africa |
| title_short | Dating deposition and low-grade metamorphism by in situ U-Pb geochronology of titanite in the Paleoproterozoic Timeball Hill Formation, southern Africa |
| title_sort | dating deposition and low-grade metamorphism by in situ u-pb geochronology of titanite in the paleoproterozoic timeball hill formation, southern africa |
| topic | SHRIMP Stratigraphy Tuff Zircon U--Pb geochronology Titanite |
| url | http://hdl.handle.net/20.500.11937/22987 |