Laser-ablation split-stream ICP petrochronology

•New petrochronologic technique: laser-ablation split-stream (LASS) ICPMS.•LASS provides simultaneous U–Th–Pb and elemental abundances.•LASS provides accurate, precise and rapid analyses.

Laser-ablation split-stream (LASS) analysis—high-speed, high spatial-resolution, simultaneous isotopic and elemental analysis—enables petrochronology at a new level, through the interpretation of isotopic dates combined with elemental abundances and/or isotopic tracers. This contribution begins with an introduction to petrochronology, presents a new LASS technique using dual multi-collector–single-collector inductively-coupled plasma mass spectrometry, and offers examples of how this technique is used to decipher the evolution of rocks with complex geologic histories.