【摘要】 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。更多还原

【Abstract】 Thermochronological studies suggest that two types of high-potassic magmatism occur in eastern Tibet and the time of igneous activities corresponds to 40-28 Ma and 16-0 Ma, respectively. Their different characteristics in geologic settings, rock types and geochemistry indicated that the early phase was derived from partial melting of an enriched subcontinental mantle in transpression and the late phase was originated from a depleted mantle enriched by recent metasomatism in extension of eastern Asia and Tibet.更多还原