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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 the the basin has Precambrian metamorphic basement. This is a report of zircon SHRIMP U-Pb dating results of a meta-diorite sample, which was The SHRIMP analyzes 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.