青藏高原松多地区温木朗蛇绿岩的发现及其地质意义

在藏南工布江达县松多地区温木朗沟发现了一套蛇绿岩,命名为温木朗蛇绿岩。温木朗蛇绿岩大地构造位置处于中冈底斯板块和南冈底斯板块的交界处。通过详细的野外地质调查和室内岩相学研究,温木朗蛇绿岩露头呈南北向分布,岩石端元包括蛇纹岩、超基性堆晶杂岩、变质辉长岩、变质玄武岩、绿片岩,各端元主要呈断层接触,变形变质较强;在蛇纹岩和变质玄武岩中均发现了花岗质片麻岩,在接触界线处存在冷凝边和烘烤边现象,推测其原岩为斜长花岗岩。温木朗蛇绿岩各端元出露相对齐全,是古特提斯洋壳残留的直接证据,对研究青藏高原古特提斯洋演化及冈底斯板块中部构造演化具有重要意义。

The discovery of Wenmulang ophiolite in Songduo area of the Tibetan plateau and its geological significance

Ophiolite was found for the first time in Wenmulang of Songduo area, Ganbo'' gyamda County, southern Tibet. The ophiolite is located between the Middle Gangdise plate and the southern Gangdise plate. According to the detailed field geological exploration and indoor petrographic identification, the authors found that the outcrop is distributed from north to south and consists of serpentine, ultramafic cumulate complex, metamorphic gabbro, metamorphic basalt and green schist, with fault contact between them. They have experienced deformation and metamorphism. In the metamorphic peridotite and metamorphic basalt, the authors found invasion of plagioclase granite veins, exhibiting chilled border and baking border near the boundary. The authors hold that the original rock was plagioclase granite. The ophiolite endmember is outcropped relatively completely, which serves as direct evidence for Paleo-Tethys oceanic crust residual and is also important for studying the tectonic evolution of Middle Gangdise plate.