SHRIMP U-Pb ages of perovskite from Yakutian kimberlites

This paper reports new U-Pb ages for perovskite in kimberlites and related rocks from Yakutia, analysed in polished sections using the SHRIMP ion microprobe. Kimberlitic perovskites are more abundant and on average contain more uranium than kimberlitic zircons, but also contain more common lead. Pb-206/U-238 ages determined on six different pipes in the Daldyn and Alakit fields, including four determinations from Udachnaya, range from 353 to 367 Ma. A 245+/-3 Ma age for the Ulakhan 1 pipe (Kharamay field) resolves a previous age conflict there and provides a temporal link with the eruption of the Siberian trap flood basalts. Ages of ca 230 Ma for kimberlite dikes from the Middle Kuonapka field are at odds with previous Rb-Sr data, but consistent with zircon U-Pb and fission track data for the area. Micaceous picrites in the Biriginde field have been dated at 193+/-4 Na, an age not previously recorded in the region.