Monazite geochronology (EPMA)

Present in a wide variety of rock types, monazite is a robust geochronometer capable of recording multiple crystallization events.

EPMA is an accurate, non-destructive, high resolution dating technique

In-situ dating of monazite by measuring Y, U, Th and Pb allows the linking of microstructure and geochronology data, thus providing a new type of information for geologists.

Electron Probe Microanalysis outperforms standard mass spectrometry methods by offering high spatial resolution: with spot size less than 1 µm, the lateral resolution is 10 to 100 times better than with isotopic methods. The high spectral resolution and reproducibility of the CAMECA WDS brings unmatched precision and accuracy to the trace element measurements, making the CAMECA electron microprobes best suited tool for monazite dating at submicron scales.

Shown above: Monazite from Boothia Peninsula, Nunavut, Canadian Artic. The quantified high resolution X-ray maps reveal the spatial variation of the geochemically important elements in order to guide further quantitative analysis. Several generations of monazite growth are represented, of foremost interest is the high Y rim and fracture filling monazite (ca.~1800 Ma) which has penetrated much older monazite (ca~2400 Ma). Sample courtesy of Dr. M.J. Jercinovic and Dr. R. G Berman, University of Massachusetts, Amherst, MA, USA and Geological Survey of Canada, Ottawa, Canada