Microprobe monazite dating

microprobe monazite dating

How was electron microprobe dating of monazite developed in the 90s?

This paper is a testimony of how electron microprobe dating of monazite was developed in the early days of this technique, in the 90s. Five contributions have been collected from Nagoya, Clermont-Ferrand, Orléans, Salzburg, and Amherst. The technique was designed in Nagoya by Professor Suzuki, using an old JXA-5A JEOL electron microprobe.

How to determine the age of crystallization in monazite?

The robust Th-U-Pb system of monazite ( Parrish, 1990, Cherniak and Pyle, 2008) allows a precise determination of crystallization ages by means of chemical dating with the electron microprobe in thin sections ( Suzuki et al., 1991, Montel et al., 1996, Suzuki and Kato, 2008 ).

Is there an EPMA dating method for monazite?

Electron probe microanalysis (EPMA) dating of monazite has been developed over decades. However, limited by the detectability and analytical sensitivity of dating-related elements (Th, Pb, U and Y), the EPMA dating has been restricted to geological research.

Does monazite record the history of the host rocks?

After dating monazite from various migmatite rocks, we concluded that monazite, like zircon, records the complex history undergone by the host rocks ( Cocherie et al., 2005 ).

What is Monazite geochronology?

Monazite geochronology is a dating technique to study geological history using the mineral monazite. It is a powerful tool in studying the complex history of metamorphic rocks particularly, as well as igneous, sedimentary and hydrothermal rocks. The dating uses the radioactive processes in monazite as a clock.

Can EPMA dating of monazite be used for geological research?

… Electron probe microanalysis (EPMA) dating of monazite has been developed over decades. However, limited by the detectability and analytical sensitivity of dating-related elements (Th, Pb, U and Y), the EPMA dating has been restricted to geological research.

How is Empa used in monazite geochronology?

EMPA is employed in monazite geochronology especially for in-situ chemical dating (total-Pb dating). The high content of U, Th and Pb in monazite match with the requirement arising from the relatively higher lower detection limit.

Does monazite record the history of the host rocks?

After dating monazite from various migmatite rocks, we concluded that monazite, like zircon, records the complex history undergone by the host rocks ( Cocherie et al., 2005 ).

What is Monazite geochronology?

Monazite geochronology is a dating technique to study geological history using the mineral monazite. It is a powerful tool in studying the complex history of metamorphic rocks particularly, as well as igneous, sedimentary and hydrothermal rocks. The dating uses the radioactive processes in monazite as a clock.

How is monazite formed from igneous rocks?

One mode of monazite formation is crystallization from an igneous melt. The concentric zoning pattern reflects the changing composition of the melt which affects the composition of the crystallizing monazite. Sector zoning is also associated with the crystallization of monazite in a melt.

Is Monazite radioactive?

Monazite is radioactive due to the presence of thorium and, less commonly, uranium. The radiogenic decay of uranium and thorium to lead enables monazite to be dated through monazite geochronology. Monazite crystals often have multiple distinct zones that formed through successive geologic events that lead to monazite crystallization.

How can we identify compositional domains in monazite?

Maps of elemental Y, Th, Pb, U have proven useful in identifying compositional domains in monazite. Estimated ages are calculated across the compositional map by analysing the concentration of Th, Pb and U by the total-Pb dating method. The result is then used to generate an age map which approximately identifies all the age domains.

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