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The North Dabie Metamorphic Complex (NDC) is a suite of gray gneiss, mainly of tonalitic gneiss.Sm-Nd isochron age of 1047±44.5Ma, εNd =-8.99 and γ=0.998 are obtained. Nd model ages (TDM) and Pb model ages also indicate an ancient crust-derived source for the gray gneisses. Either the 87Sr/86Sr present ratios (>0.707) and the present εNd value (-8.84~-23.56), or the εNd value (-8.99) determined by isochron clearly constrained a crust source for the gray gneisses in NDC. Hence it can be inferred that the gray gneisses of NDC were derived from a reworking ancient middle to lower continental crust The generation and evolution process is closely related to the subduction of the Yangtze plate beneath the North China plate. The intrusion of the Yanshan granitic magma caused the last and the strongest tectothermal even on the gray gneisses
The North Dabie Metamorphic Complex (NDC) is a suite of gray gneiss, mainly of tonalitic gneiss. Sm-Nd isochron age of 1047 ± 44.5Ma, εNd = -8.99 and γ = 0.998 are obtained. Nd model ages (TDM) and Pb Either the 87Sr / 86Sr present ratios (> 0.707) and the present εNd value (-8.84 ~ -23.56), or the εNd value (-8.99) determined by isochron clearly constrained a crust source for the gray gneisses in NDC. Therefore it can be inferred that the gray gneisses of NDC were derived from a reworking ancient middle to lower continental crust The generation and evolution process is closely related to the subduction of the Yangtze plate beneath the North China plate. The intrusion of the Yanshan granitic magma caused the last and the strongest tectothermal even on the gray gneisses