Report of March 2013 International Workshop in Charleston

Welcome to the LA-ICP-MS U-(Th-)Pb Data Handling page. This area of the website represents a collaboration between established ‘groups’ working on improving U-(Th-)Pb geochronology data for the benefit of the whole scientific community. Recognition of the problems and initiation of effort was started in the TIMS U-Pb community which combined with the Ar-Ar community to establish EARTHTIME, a collaboration to improve inter-calibration of the geological timescale. Alongside this effort EarthChem was established to appropriately archive the large volume of geochemical data generated internationally and improve value for money and applicability of data from funding-agency approved projects. EarthChem has thousands of entries in its database and is free to use for academic researchers.

Since 2006, the laser ablation U-(Th-)Pb community has been working to address problems of inter-comparability within our technique. In attempting to establish and promote best practice in the acquisition, handling, reporting and interpretation of laser ablation U-(Th-)Pb data our ideals follow closely those of our geochronology community colleagues in trying to improve our science using better metrology-based practices. We are recognized as a Special Interest Group of the International Association of Geoanalysts (IAG) and have established a Working Group on LA-ICP-MS U-(Th-)Pb Geochronology to highlight and improve key aspects of our practices. Our role, goals and objectives are described here.

In combining skills from computer, geological and analytical sciences through CIRDLES, EarthChem, EARTHTIME and the Working Group, we are striving to achieve the best possible approach in utilising laser ablation ICP-MS U-(Th-)Pb data whilst taking advantage of mutually beneficial outcomes such as establishing better-defined internationally-available reference materials and comparability of geochronology results from different methods. This collaborative ethic has already proved fruitful with an NSF grant awarded to Jim Bowring (College of Charleston) as PI, with co-PIs George Gehrels (U. Arizona), Doug Walker (U. Kansas) and Sam Bowring (MIT), to develop community-driven data processing and data archiving software for LA-ICP-MS U-(Th-)Pb data. This project will integrate the latest data reduction and uncertainty propagation practices now used in the ID-TIMS U-Pb community, with the Geochron Geological Database Portal, while achieving maximum value from large funding agency-derived datasets and helping to improve inter-comparison of LA-ICP-MS data. The San Francisco workshop (Dec 2009) sought to highlight some of these components. Although many data processing packages and spreadsheets exist, the continued development and harmonization of current systems along with development of new, more sophisticated systems capable of handling the diversity of platforms and data outputs available within the LA-ICP-MS community, is a very important end-goal if we as a community are to be successful in improving data processing and reporting standards as well as the inter-comparability of data.

We hope you find these pages useful and informative and we encourage and ask for your active participation in the discussions and planned activities. We hope you will support this community effort and we are happy to receive any comments and suggestions you would like to make that would improve the site and direct the efforts of the community towards its goals. We look forward to liasing with you all on this initiative which we feel is of paramount importance for our science at this time.

Very best regards,

Matt Horstwood, Jan Kosler, Simon Jackson, Norman Pearson, Paul Sylvester (Co-ordinators, Working Group on LA-ICP-MS U-(Th-)Pb Geochronology) in collaboration with our EARTHTIME, CIRDLES and EarthChem colleagues.