​Laser Ablation-ICP-MS applied to U-Series and U-Pb Carbonate dating

​Event Type: Seminar
Event Date: 8 November 2019 - 4:00pm to 5:00pm
Venue: ASE 3D Viz Laboratory Room (N2-B1c-16c)
Speaker: Dr. Marcel Guillong

About the speaker:

In 2004 Guillong finished his PhD in Chemistry in the group of Detlef Günther at ETH Zürich on “LA-ICP-MS: LA system developments and investigations on elemental fractionation” establishing the importance of ICP parameters on element fractionation due to differences in aerosol particle size. At Paul Scherrer Institute he built a LA system for highly radioactive samples, before he moved into Geology at ETH, focusing on sulphur and fluid inclusion analysis under Prof. C.A. Heinrich. 2009-2011. He worked as Lab manager at CODES Australia getting into the U-Pb dating business. Since 2012 he is back at ETH Zürich as Lab manager developing new dating strategies using LA-ICP-MS.

About the event:

Laser Ablation-ICP-MS is a relatively cheap, fast and widespread technique for in situ trace element and isotopic analysis. A careful evaluation of interferences and their correction is necessary to measure the small amounts of the intermediate decay product 230Th for U-Series dating. Technique, method and pit falls will be discussed on the example of Zircon. Recently we could apply this method, thanks to the versatility of LA to silica undersaturated volcanic tuffs by dating Garnets. Latest measurements show that it might be possible to combine multiple co-genetic minerals to improve the age defining isochron using Apatite, Zircons and other minerals.

LA-ICP-MS offers some huge advantages in U-Pb dating of Carbonates due to the possibility of fast screening and acquiring hundreds of point analyses within reasonable amount of time to better define an isochrone. Some aspects of matrix effects, precision and accuracy will be discussed.