TS-Mnz – A new monazite age reference material for U-Th-Pb microanalysis

A single megacryst of Neoproterozoic monazite (“TS-Mnz”) was investigated by electron probe microanalysis (EPMA), Raman microspectroscopy, U-Pb dating isotope dilution-thermal ionization mass spectrometry (ID-TIMS), and U-Th-Pb trace element analysis laser ablation inductively coupled plasma (LA-ICPMS). The contains both distinct unaltered domains that are either homogeneous or zoned, altered with secondary inclusions ThSiO4 along fractures. Altered can be easily recognized in backscattered images avoided during microanalysis. ID-TIMS measurements two laboratories revealed slight reverse discordance data provided 207Pb/235U mean dates 908.2 ± 1.5 Ma (95% conf., MSWD = 2.9) 910.42 0.34 (2?, 1.0). Three individual LA-ICPMS sessions yielded 899.8 6.9 0.10), 896.3 6.5 0.18) 901.9 2.0 0.57), 208Pb/232Th 909.2 5.8 0.36), 915.1 11 0.31) 909.9 0.56). lower precision the respect to technique hides discrepancies between as well discordance, which is common for monazite. interpreted related standardization setup analytical techniques; however, minor variance analyzed spots also cannot excluded. Further microprobe U-Th-total Pb 914.6 0.99) 922.9 3.1 4.3) fragments TS-Mnz. round-robin test employing TS-Mnz a primary reference material various samples known age unknowns accurate Th-Pb within errors ages. To conclude, despite compositional variations reveals relatively reproducible U-Pb, proposed new in-situ recommended ages (2?) 910.7 1.3 conf.), respectively.