热年代学研究表明 ,青藏东缘存在两期新生代高钾岩浆活动 ,其活动时限分别为 40～ 2 8Ma和 16～ 0Ma。两期高钾岩石在地质背景、岩石类型和地球化学特征上明显不同 ,表明早期高钾岩石是在转换压缩过程中产生的 ,起源于富集地幔的部分熔融 ,而晚期高钾岩石则与东亚和青藏地区构造伸展有关 ,起源于新近交代富集的亏损地幔。 Thermochronological studies show that there are two Cenozoic high potassium magmatic activities in the eastern margin of the Qinghai-Tibet Plateau with active periods of 40 ~ 28 Ma and 16 ~ 0 Ma respectively. The two high-K rocks are obviously different in their geological backgrounds, rock types and geochemical characteristics, indicating that the early high-K rocks were produced during the process of transformation and compression, originated from the partial melting of the enriched mantle whereas the later high-K rocks were associated with East Asia It is related to the tectonic extension of the Qinghai-Tibet area and originated from the depleted mantle newly enriched by the Qinghai-Tibet Plateau.