Interactive programs of MC-ICPMS data processing for 230Th/U geochronology

Multiple-collector inductively coupled plasma mass spectrometric (MC-ICPMS) techniques, with high-precision and high-throughput capabilities, have been applied to Th-230/U geochronology since the late 1990s. Significant effort has been dedicated to refining such techniques, but few studies have emphasized the development of data processing schemes. This study presents a convenient data-processing protocol that allows users to easily transform measured MC-ICPMS data to accurate Th-230/U ages, accounting for most sources of analytical uncertainty. This protocol comprises two interactive programs UTh_Review and UTh_Reduction, written with the MATLAB programming language. UTh_Review is designed to graphically present raw data of ion beam intensities and filter out outliers. UTh_Reduction enables data reduction, age calculations and data storage. This newly-developed protocol was validated by long-term measurement of delta U-234 in the Harwell uraninite isotope reference solution (HU-1) and an inter-laboratory comparison of Th-230/U dating of stalagmite. This methodology of data processing can easily be modified to fit previously published U-Th data acquisition strategies.