中文摘要：

皮羌辉长岩体位于塔里木盆地柯坪断隆西部，皮羌村北约15km处。该岩体的围岩包括志留系、泥盆系和石炭系一二叠系，新近系不整合覆盖其上。采集该辉长岩样品进行单矿物分离，取分离出的斜长石进行Ar-Ar定年。700～1400℃的8个加热阶段析出的39Ar为总量的95．89％，在坪谱图上得到一个较稳定的坪，坪年龄为265．5±1．2Ma；与之相对应的等时线年龄为267．29±5．62Ma。结合区域地质分析，皮羌辉长岩体的侵人时代为中二叠世早期；是塔里木二叠纪岩浆活动的一部分。其侵入后基本未受后期构造热事件影响。

英文摘要：

Piqiang gabbroid is 15 km north of Piqiang village, west Keping fold-thrust belt, Tarim Basin. The country rocks of Piqiang gabbroid include Silurian, Devonian, Carboniferous and Permian. Neogene and Quaternary uncomfortably overly on it. Gabbro sample was collected at the SE margin of Piqiang gabbroid for individual mineral separating. Plagioclase was selected for Ar-Ar dating. 8 heating stages of 700 - 1 400℃ gaves a stable plateau with the plateau age of 265.5±1.2 Ma. The related isochronal age is 267.29±5.62 Ma. Consulting with the regional geological data, Piqiang gabbroid intruded at early Middle Permian, without obvious influence of tectonic-thermo event after the intrusion.