The discovery of Wenmulang ophiolite in Songduo area of the Tibetan plateau and its geological significance
WANG Bin;XIE Chaoming;LI Cai;LIU Yiming;YU Yunpeng;College of Earth Sciences,Jilin University;
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.