大别造山带白马尖花岗岩体的钕、锶同位素地球化学研究

Nd-Sr Isotope Geochemistry of the Baimajian Granite in the Dabie Orogen

大别造山带白马尖花岗岩体属燕山期侵入岩,为中生代大别山区岩浆活动的产物,为碰撞后花岗岩。锶、钕同位素数据及稀土元素数据表明,白马尖花岗岩体为壳幔混合型。1.2～1.7 Ga的钕模式年龄为其源岩的平均地壳存留年龄。北大别花岗岩类岩石的物质来源并不一致。

The Baimajian granite in the Dabie orogen is a Yanshanian intrusion resulting from Mesozoic magmatism. It is post-collisional granite. Nd and Sr isotope and REE data show that the intrusion is of crust-mantle mixing type. Their Nd model age is 1. 2~1. 7 Ma, which is the average crustal retention age of their protoliths. The material sources of the granitoid rocks at Baimajian in the northern Dabie are different.