Development of SHRIMP

Abstract

The advent of SHRIMP, the Sensitive High Mass-Resolution Ion Microprobe, defines a milestone in Australian geochronology. SHRIMP was the first ion microprobe dedicated to geological isotopic analysis and opened up zircon geochronology to in situ analysis where single domains could be directly targeted. The ease and simplicity of the SHRIMP procedures facilitated rapid analyses of zircon populations. In Archean quartzites of Western Australia Hadean (>4 Ga), zircons were discovered as one of the first scientific reports from SHRIMP. The Hadean zircons gave access to the early history of the Earth and represent a unique resource for determining processes operating during this period. SHRIMP has often been regarded as an instrument solely for U–Pb geochronology, but applications in stable-isotope analysis, cosmochemistry, and trace-element abundance measurements were all parts of the early development. Advances in SHRIMP design have proceeded to enable multiple collection, stable-isotope analysis through negative ion measurement, and construction of different versions of SHRIMP for specific applications. The reverse geometry SHRIMP RG design allows ultra-high mass resolution, whereas the SHRIMP SI will allow a dedicated stable-isotope instrument for light elements.

Key Words:

• geochronology
• isotope analysis
• SHRIMP
• uranium–lead dating

Acknowledgements

We are grateful to successive Research School of Earth Sciences Directors (and in particular Anton Hales) for initial and continued support of the SHRIMP concept, instrumentation and facilities. We would like to thank Zane Bruce who carried out the imaging work for the Hadean zircons and Australian Scientific Instruments (ASI) who provided the base SHRIMP II diagram. Thanks to Bob Pidgeon for his insightful review. This work was partially supported by the ARC Discovery Program. We are grateful for the support of SHRIMP SI by Australian National University, a consortium of Australian universities including Curtin, Queensland, Melbourne, Wollongong, and Tasmania (through CODES), government research organisations (CSIRO, Geoscience Australia) and ASI.

Notes

*Extended abstract prepared for the First International Conference on Secondary Ion Mass Spectrometry held in Münster in 1977 (Clement et al. 1977) outlining the original concept and design for SHRIMP: the conference proceedings volume was never published.