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青海龙羊峡地区侵入体岩石类型为正长花岗岩、 二长花岗岩及花岗闪长岩, 岩石中Al2O3=11.78%~15.11%, K2O=3.57%~5.58%, A/NK=1.14~1.63, A/CNK=0.87~0.97, TFeO/ (TFeO+MgO) =0.74~0.91, 岩石具偏铝质中-高钾钙碱性花岗岩特征.用LA-ICP-MS测得龙羊峡侵入岩体的正长花岗岩和二长花岗岩中的锆石206Pb/238U年龄为243.5±2.9Ma (MSWD=5.2) 和247.2±1.7Ma (MSW