中文摘要：

本文应用SHRIMP U—Pb测年方法对取自辽西医巫闾山花岗岩的锆石进行定年。所测锆石样品新鲜、未风化，岩性为粗粒黑云母二长花岗岩。经过精确的测试过程，得到约2500Ma、224Ma和161Ma的3个时间段年龄值。约2500Ma的上交点年龄是太古宙古陆核演化的记录，224Ma的岩浆结晶年龄是印支期构造热事件的记录，161Ma的岩浆侵位年龄是燕山中新生代陆内造山带主造山期造山作用的记录，也是区域构造体制转换开始的时代。

英文摘要：

The SHRIMP dating technique was applied to determine the U-Pb ages of zircons from the Yiwulueishan granite, western Liaoning. The zircon samples were fresh and unweathered. The rock is coarse-grained biotite monzogranite. Through accurate measurements three ages were obtained; they are -2500, 224 and 161 Ma. The upper intercept age of-2500 Ma is the record of the evolution of the Archean old continental nucleus; the crystallization age of 224 Ma is the record of the Indosinian tectono-thermal event; and the magmatic emplacement age of 161 Ma is the record of orogeny of the main orogenic phase of the Meso-Cenozoic in,continental orogenic belt in the Yanshan area and also an age when the regional structural regime started transition.