攀西会理猫猫沟环状碱性杂岩体中碱性长石正长岩为钠质碱性岩, 含有暗色造岩矿物钙铁辉石、铁韭闪石和黑云母, 其中的锆石绝大部分(80%以上)是具有老核新壳的岩浆复合型锆石. 对这些锆石进行了SHRIMP法U-Pb定年, 结果显示发现, 岩浆锆石和岩浆复合型锆石的新壳的206Pb/238U加权平均年龄为224 8 Ma, 反映出碱性长石正长岩的结晶时间为晚三叠世; 岩浆复合型锆石老核的年龄为两 段, 一是206Pb/238U年龄622 ~ 691 Ma, 二是207Pb/206Pb年龄2692 ~ 2818 Ma, 分别代表了捕获的新元古代和太古代古老结晶基底中的锆石年龄. 晚太古代锆石老核的产出为康滇古陆地区存在太古代的古老基底提供了同位素年代学依据. The Alkaline feldspar syenite in the Rincoiyugou ditch alkaline complex is a sodium alkaline rock with dark-colored rock-forming minerals, such as calcium iron pyroxene, iron allchite and biotite, among which zircon Most of the zircons (over 80%) are magmatic composite zircons with old nuclei and new crusts.The SHRIMP U-Pb dating of these zircons shows that the new crust of magmatic zircons and magmatic composite zircons The weighted average age of 206Pb / 238U is 224 8 Ma, which indicates that the crystallization time of Alkaline feldspar syenite is late Triassic. The age of magmatic composite zircon is two stages, one is 206Pb / 238U, 691 Ma, and the 207Pb / 206Pb ages from 2692 to 2818 Ma, representing the zircon ages of the captured Neoproterozoic and Archean ancient crystalline substrates, respectively The existence of ancient Archean basement provides the basis of isotopic chronology.