birkremite

Zircon SHRIMP U-Pb dating was performed on alkali feldspar-quartz syenite and arfvedsonite alkali granite in the Cida alkali complex in the Dechang area, in the Panxi paleorift.

对产于攀西古裂谷带内的德昌地区茨达碱性杂岩体中的碱长石英正长岩和钠铁闪石碱性花岗岩进行了锆石SHRIMP U-Pb年龄测定,年龄结果分别为221Ma±6Ma和225Ma±2Ma,表明该碱性岩的结晶年龄或成岩年龄相当于晚三叠世,同时暗示攀西古裂谷的张裂时间为三叠纪。