[LPT] Electron Microprobe U-Th-Pb Monazite Dating


En | Monazite is widely used in petrochronological studies, as it is one of the most common radioactive minerals and one of the main hosts of U and Th in igneous and metamorphic rocks. Among the different methods used for its dating, the electron microprobe stands out for its operational cost and spot size considerably lower than other techniques. Check out our #learningpetrotools to learn more about its premises and applications.


PT | A monazita é amplamente utilizada em estudos petrocronológicos, pois é um dos minerais radioativos mais comuns e um dos principais hospedeiros de U e Th em rochas ígneas e metamórficas. Dentre os diferentes métodos utilizados na sua datação, a microssonda eletrônica se destaca pelo custo operacional e tamanho do spot consideravelmente inferiores em relação a outras técnicas. Arrasta pro lado e confira no nosso #learningpetrotools mais sobre suas premissas e aplicações.


Author: Paulo Paiva-Silva 

References

  • Akame, J.M., Schulz, B.; Owona, S; Debaille, V. (2021). Monazite EPMA-CHIME dating of Sangmelima granulite and granitoid rocks in the Ntem Complex, Cameroon: Implications for Archean tectono-thermal evolution of NW Congo craton. Journal of African Earth Sciences, 181: 104268, https://doi.org/10.1016/j.jafrearsci.2021.104268.
  • Bea, F. (1996). Residence of REE, Y, Th and U in granites and crystal protoliths: implication for the chemistry of crystal melts. Journal of Petrology, 37: 521-552. https://doi.org/10.1093/petrology/37.3.521
  • Boatner, L. A. (2005). Synthesis, structure, and properties of monazite, pretulite, and xenotime. Reviews in Mineralogy and Geochemistry, 48: 88-121. https://doi.org/10.2138/rmg.2002.48.4
  • Engi, M. (2017). Petrochronology based on REE-minerals: monazite, allanite, xenotime, apatite. Reviews in Mineralogy and Geochemistry, 83(1), 365-418. https://doi.org/10.2138/rmg.2017.83.12
  • Finger, F., Krenn, E. (2007). Three metamorphic monazite generations in a high-pressure rock from the Bohemian Massif and the potentially important role of apatite in simulating polyphase monazite growth along a PT loop. Lithos, 95: 103-115. https://doi.org/10.1016/j.lithos.2006.06.003
  • Harlov, D. E., Wirth. R., Hetherington. C. J. (2007). The relative stability of monazite and huttonite at 300-900 ºC and 200-1000 MPa: metassomatism and the propagation of metastable mineral phases. American Mineralogist, 93: 806-820. https://doi.org/10.2138/am.2007.2459
  • Harlov, D. E., Hetherington, C. J. (2010). Partial high-grade alteration of monazite using alkali-bearing fluids: experimental and nature. American Mineralogist, 95: 1105-1108. https://doi.org/10.2138/am.2010.3525
  • Harlov, D. E., Wirth, R., Hetherington, C. J. (2011). Fluid-mediated partial alteration of monazite: the role of coupled dissolution-reprecipitation during apparent solid-state element mass transfer. Contributions to Mineralogy and Petrology, 162: 329-348. https://doi.org/10.1007/s00410-010-0599-7
  • Just, J., Schulz, B., de Wall, H., Jourdan, F., Pandit, M. K. (2010). Monazite CHIME/EPMA dating of Erinpura granitoid deformation: implications for Neoproterozoic tectono-thermal evolution of NW India. Gondwana Research, 19: 402-412. https://doi.org/10.1016/j.gr.2010.08.002
  • Montel, J-M., Foret, S., Veschambre, M., Nicollet, C., Provost, A. (1996). Electron microprobe dating of monazite. Chem Geol 131:37–53. https://doi.org/10.1016/0009-2541(96)00024-1
  • Ni, Y., Hughes, J. M., Mariano, A. N. (1995). Chrystal chemistry of monazite and xenotime structures. American Mineralogist, 80: 21-26. https://doi.org/10.2138/am-1995-1-203

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