摘要
天堂寨片麻状花岗岩,侵位于大别群变质岩系。本文从岩相学、岩石化学、稀土元素地球化学、矿物化学、捕虏体以及矿物之间平衡关系论证了该岩体并非混合交代成因,而是壳源岩浆结晶产物,属I′_u型花岗岩。片麻构造形成与应力作用和塑性变形有关。
The Tiantangzhai massif, outcropping in the centre of the Dabie mountains region and located to the NE of Luotian county, intruded the meta-morphic rocks of the Dabie Group in Early Cretaceous time. It consists mainly of gneissic biotite monzonitic granite with average SiO2 of 71.7%, Eu/Eu 0.69 and La/Yb 49.39. M' -value of biotite is 47.24-48.1 (M'=Mg ×100/CMg + Fe + Mn + Ti + Al) and KDBi-FeHo is 1.03. It shows that the biotite was in equilibrium with the hornblende during emplacement. The emplacement depth of the massif is more than 10-13km and is the product of crystallization of the crust-derived magma, rather than migmatitic or metaso-matic genesis. It belongs to I'u-type granite. The gneissic structures are formed by the stress and are the results of plastic deformation.
出处
《地球学报》
EI
CAS
CSCD
1991年第1期147-158,共12页
Acta Geoscientica Sinica
