Monazite dating koreans dating other asians
Preliminary results of a workshop at NMT given by Michael J.
Jercinovic (University of Massachusetts) Assumption: No non-radiogenic lead in monazite or at least very little If you can precisely measure U, Th, and Pb (in ppm), you can solve this equation iteratively for lead to obtain an age Map thin section with the microprobe Ce, Fe, Y to find all monazite crystals Map monazite grains Th, Y, U to see chemical domains Measure major elements for matrix corrections Spot analyses Measure: U, Th, Pb, Y (to correct for peak interference with Pb--a minor correction) Solve the age equation See an abstract of Williams et al., 1999 which describes the structural, metamorphic, and temporal setting for Proterozoic rocks in northern New Mexico and discusses the pervasive ~1.4 Ga metamorphic overprint of these rocks.
This will undoubtably be a very fruitful avenue of research for years to come.
The probe data overall are consistent with the isotopic age, but with considerable variability (see the data spreadsheet, and the grain maps and images for details).
The complex age domains, chemical zoning, and generally anhedral crystal morphology may collectively imply slow cooling at ~1.4 Ga and/or repeated magmatic-metamorphic pulses during the ~1.4 Ga tectonometamorphic event that in the Rincon Range may have lasted from perhaps 1460 Ma until 1380 Ma.
The best hope for finding older monazites in Proterozoic rocks from this and other ranges is likely to be within the cores of M1 garnets and other porphyroblasts.
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.
Search for monazite dating:
To obtain the geological age, we need to know the relationship between the two.