Ion microprobe U-Pb dating and REE analyses of phosphates in H4-chondrite, Yamato-74371
作者： Kentaro Terada , Yuji Sano
DOI: 10.1029/2001GL013945
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摘要: [1] U and Pb isotopes rare earth elements (REEs) in individual phosphate grains from H4-chondrites, Y-74371 were measured by using an ion microprobe. Nine analyses of whitlockite (merrillite) five apatites indicate a total Pb/U isochron age 4533 ± 40 Ma (2 sigma), which are consistent with the results previous Thermal ionization mass spectrometer (TIMS). The observed 4525 30 however, is younger than those works. On other hand, time difference between 4601 94 sigma) not observed, because large uncertainties. REE abundance patterns whitlockites normalized to CI chondrite characterized almost constant enrichment 200–800 times abundance, striking negative Eu anomaly. abundances lower grains, vary appreciably among different grains. remarkable correlation anomaly (Eu/Eu*) concentration confirmed, but significant formation observed.
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