摘要
The basement of the Songliao Basin mainly contains low-grade metamorphic rocks and granites. It has been long disputed whether the basin has Precambrian metamorphic basement. This is a report of zircon SHRIMP U-Pb dating results of a meta-diorite sample, which was taken from the Si-5 drilling hole in the southern portion of the Songliao Basin. The SHRIMP analyses indicate that the meta-diorite with a weighted mean 207Pb/206Pb age of 1839±7 Ma (2σ, n = 8) was emplaced during Paleo-Proterozoic time. Additionally, the meta-diorite has old Nd model ages (TDM1: 2999Ma; TDM2: 2849Ma). These data suggest that the south- ern part of the Songliao Basin do possess Precambrian base- ment.
The basement of the Songliao Basin mainly contains low-grade metamorphic rocks and granites. It has been long disputed whether the basin has Precambrian metamorphic basement. This is a report of zircon SHRIMP U-Pb dating results of a meta-diorite sample, which was taken from the Si-5 drilling hole in the southern portion of the Songliao Basin. The SHRIMP analyses indicate that the meta-diorite with a weighted mean ^207pb/^206pb age of 1839±7 Ma （2σ, n = 8） was emplaced during Paleo-Proterozoic time. Additionally, the meta-diorite has old Nd model ages （TDMI： 2999Ma; TOM2： 2849Ma）. These data suggest that the southern part of the Songliao Basin do possess Precambrian basement.
基金
supported by the National Natural Science Foundation of China(Grant Nos.40473030 and 40234045)
Chinese Academy of Sciences(Grant No:KZCX2-104).
