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对大别造山带北部主簿源中生代花岗岩侵入体及其围岩片麻岩进行了矿物氧同位素分析，同时对同一样品进行了矿物 Rb- Sr内部等时线定年。结果表明，花岗岩和片麻岩矿物的氧同位素温度大小顺序为：角闪石 >磁铁矿 >榍石 >石英 >黑云母 >长石，遵循缓慢冷却条件下扩散控制的氧同位素交换封闭顺序，指示这些岩石没有受到后期热液蚀变的扰动。根据黑云母-长石-磷灰石-全岩内部 Rb- Sr等时线测定，花岗岩的年龄为 (118± 3) Ma，代表了岩浆侵位冷却年龄；片麻岩的年龄为 (122± 1) Ma，代表了片麻岩受大面积燕山期岩浆侵位热烘烤达到高温同位素平衡后的冷却年龄。因此，矿物之间的氧同位素平衡与否 ,能够对矿物 Rb- Sr体系封闭后平衡状态的保存性以及矿物内部等时线定年的有效性予直接制约。
Oxygen isotope analyzes of mineralogical isotopes of Mesozoic granitogenic intrusions and their surrounding gneisses from the northernmost Dabie orogenic belt were carried out, and isotopic dating of the mineral Rb-Sr was carried out on the same sample at the same time. The results show that the order of oxygen isotopic temperature of the granites and gneiss minerals is: amphibole> magnetite> limnite> quartz> biotite> feldspar. Following the diffusion-controlled oxygen isotope exchange closure sequence under slow cooling conditions, Indicating that these rocks were not disturbed by late hydrothermal alteration. The age of granite is (118 ± 3) Ma, which represents the emplacement cooling age of magmatic rocks. The age of gneiss is (122 ± 1) Ma, which represents the cooling age of gneiss after high temperature isotope equilibrium due to large area Yanshanian magmatic emplacement hot bake. Therefore, whether or not the oxygen isotopes are balanced between minerals can directly restrict the conservation of the equilibrium state of the mineral Rb-Sr system after closure and the validity of the isochronal dating of minerals.