Metamorphic rates in collisional orogeny from in situ allanite and monazite dating
The prograde sequence of rare earth minerals recorded in metapelites during regional metamorphism reveals a series of irreversible reactions among silicates and phosphates. In individual samples from the northern Lepontine (Central Alps), allanite is partly replaced by monazite at 560–580 °C. Relic...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Published: |
Geological Society of America Inc
2009
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| Online Access: | http://hdl.handle.net/20.500.11937/22329 |
| _version_ | 1848750840069750784 |
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| author | Janots, E. Engi, M. Rubatto, D. Berger, A. Gregory, Courtney Rahn, M. |
| author_facet | Janots, E. Engi, M. Rubatto, D. Berger, A. Gregory, Courtney Rahn, M. |
| author_sort | Janots, E. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The prograde sequence of rare earth minerals recorded in metapelites during regional metamorphism reveals a series of irreversible reactions among silicates and phosphates. In individual samples from the northern Lepontine (Central Alps), allanite is partly replaced by monazite at 560–580 °C. Relic allanite retains its characteristic growth zoning acquired at greenschist facies conditions (430–450 °C). Coexisting monazite and allanite were dated in situ to delimit in time successive stages of the Barrovian metamorphism. In situ sensitive high-resolution ion microprobe (SHRIMP) U-Th-Pb dating of allanite (31.5 ± 1.3 and 29.2 ± 1.0 Ma) and monazite (18.0 ± 0.3 and 19.1 ± 0.3 Ma) constrains the time elapsed between 430–450 °C and 560–580 °C, which implies an average heating rate of 8–15 °C/m.y. Combined with new fi ssion track ages (zircon, 10–9 Ma; apatite, 7.5–6.5 Ma), metamorphic rates of theentire orogenic cycle, from prograde to final cooling, can be reconstructed. |
| first_indexed | 2025-11-14T07:43:13Z |
| format | Journal Article |
| id | curtin-20.500.11937-22329 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:43:13Z |
| publishDate | 2009 |
| publisher | Geological Society of America Inc |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-223292017-02-28T01:35:40Z Metamorphic rates in collisional orogeny from in situ allanite and monazite dating Janots, E. Engi, M. Rubatto, D. Berger, A. Gregory, Courtney Rahn, M. The prograde sequence of rare earth minerals recorded in metapelites during regional metamorphism reveals a series of irreversible reactions among silicates and phosphates. In individual samples from the northern Lepontine (Central Alps), allanite is partly replaced by monazite at 560–580 °C. Relic allanite retains its characteristic growth zoning acquired at greenschist facies conditions (430–450 °C). Coexisting monazite and allanite were dated in situ to delimit in time successive stages of the Barrovian metamorphism. In situ sensitive high-resolution ion microprobe (SHRIMP) U-Th-Pb dating of allanite (31.5 ± 1.3 and 29.2 ± 1.0 Ma) and monazite (18.0 ± 0.3 and 19.1 ± 0.3 Ma) constrains the time elapsed between 430–450 °C and 560–580 °C, which implies an average heating rate of 8–15 °C/m.y. Combined with new fi ssion track ages (zircon, 10–9 Ma; apatite, 7.5–6.5 Ma), metamorphic rates of theentire orogenic cycle, from prograde to final cooling, can be reconstructed. 2009 Journal Article http://hdl.handle.net/20.500.11937/22329 Geological Society of America Inc restricted |
| spellingShingle | Janots, E. Engi, M. Rubatto, D. Berger, A. Gregory, Courtney Rahn, M. Metamorphic rates in collisional orogeny from in situ allanite and monazite dating |
| title | Metamorphic rates in collisional orogeny from in situ allanite and monazite dating |
| title_full | Metamorphic rates in collisional orogeny from in situ allanite and monazite dating |
| title_fullStr | Metamorphic rates in collisional orogeny from in situ allanite and monazite dating |
| title_full_unstemmed | Metamorphic rates in collisional orogeny from in situ allanite and monazite dating |
| title_short | Metamorphic rates in collisional orogeny from in situ allanite and monazite dating |
| title_sort | metamorphic rates in collisional orogeny from in situ allanite and monazite dating |
| url | http://hdl.handle.net/20.500.11937/22329 |