Recent advances in in situ U-Pb dating of geological events by laser ablation inductively coupled plasma mass spectrometry

Abstract

LA-ICP-MS is an ideal technique for in situ analysis of a variety of matrices for trace element concentrations at the micron scale. LA-ICP-MS, with a quadrupole mass analyser in this study, can also be used for in situ U–Pb isotope ratio analysis of zircon, as now performed by many laboratories worldwide. We have also shown that it is possible to use a fairly simple analytical set-up to further utilise LA-ICP-MS for in situ U–Pb geochronology of young (Neogene) zircons and common Pb bearing minerals. This highlights the flexibility and, as yet, unrealised potential of LA-ICP-MS as an in situ analytical tool.

The developments of laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) for its application and use in geological and earth science community for academic research are discussed. This laser is proved to be stable and easy to incorporate in the laser ablation system. The advantages of LA-ICP-MS in the field of natural history include little or no sample preparation that is required for LA-ICP-MS. This technique is capable of sampling solid materials at a spatial resolution of few microns, and providing precise isotopic information and determination of trace elements at ppb level. It is necessary that the data are to a homogenous reference materials of well-known /u-Pb isotopic ratio. Laser ablation using a single spot can induce fractionization between U and Pb. It is possible to use a simple analytical set-up to utilize LA-ICP-MS for U-Pb geochronology of young (Neogene) zircons and common Pb bearing minerals.