中文摘要：

Yardoi 片麻岩屋顶被定位到向北喜玛拉雅的片麻岩屋顶(NHGD ) 最东部，南部的西藏。它由 metapelite，石榴石角闪岩，花岗石和 leucogranite 组成，并且是一个关键题目抑制形成和 NHGD 的构造进化。leucogranite 收益上的虾锆石 U/Pb 数据 35.3 ± 1 .1 妈的年龄，它比对西方的类似的 leucogranites 的实质地旧。Sr 和 Nd 同位素 systematics 显示这 leucogranite 从混合石榴石角闪岩和 metapelite 的部分融化被导出。我们的数据建议那(1 ) 在喜玛拉雅的 magmatism 的早阶段期间，融化的角闪岩脱水压到 metapelite 的；并且(2 ) 一如此的融化在中间降低的外壳力量是沿着南部的西藏的分开系统(STDS ) 开始了运动的一个主要因素。

英文摘要：

The Yardoi gneiss dome is located to the easternmost of the North Himalayan Gneiss Dome （NHGD）, southern Tibet. It consists of metapelite, garnet amphibolite, granite and leucogranite, and is a key subject to constrain the formation and tectonic evolution of NHGD. SHRIMP zircon U/Pb data on the leucogranite yield an age of 35.3±1.1 Ma, which is substantially older than that of the similar leucogranites to the west. Sr and Nd isotope systematics indicate that this leucogranite was derived from partial melting of the mixed garnet amphibolite and metapelite. Our data suggest that （1） during the early stage of Himalayan magmatism, amphibolite dehydration melting overwhelmed that of the metapelite; and （2） such a melting at middle-lower crust might be a major factor that initiated the movement along the Southern Tibetan Detachment System （STDS）.