The Shuanghe garnet-bearing paragneiss from the Dabie ultra-high-pressure (UHP) orogen occurs as an interlayer within partially retrogressed eclogite. A first UHP metamorphic stage at 680°C, 3.8-4.1 GPa is documented by Zr-in-rutile temperatures coupled with phengite inclusions (Si = 3.55) in clinozoisite and grossular-rich garnet. Relic matrix phengite and phengite inclusions in zircon rims display lower Si of 3.42. Combined with garnet compositions and Ti-in-zircon temperatures, they provide evidence for a second UHP metamorphic stage at 800-850°C, ~3.8 GPa. K E Y W O R D SDabie, partial melting, polyphase inclusion, Shuanghe, UHP metamorphism 132 |

Melt inclusions (MIs) in high-temperature metamorphic rocks provide a unique window into crustal anatexis in collisional orogenic belts and have been widely used to characterize compositions of anatectic melts as well as melting mechanisms. In this study, MIs hosted by peritectic garnet were for the first time identified in an Al 2 SiO 5 -free graywacke-type paragneiss from the Namche Barwa Complex, the Eastern Himalaya, Southeast Tibet. These MIs occur as nanogranites in the rims of porphyroblastic garnet, exhibit negative crystal shapes with an average diameter of $12 μm and consist of a mineral assemblage of biotite + quartz + plagioclase + K-feldspar ± muscovite. Rehomogenization experiments of these nanogranites were conducted at a pressure of 1.5 GPa and temperatures of 800 C, 850 C and 900 C and produced homogeneous glasses at 850 C. The homogenized glasses are strongly peraluminous and calc-alkalic in composition, with 66.43-71.31 wt.% SiO 2 , 12.64-15.06 wt.% Al 2 O 3 , high alkaline (5.41-7.22 wt.%) and low ferromagnesian (2.72-4.46 wt.%) contents. They are lower in silica and CaO but higher in K 2 O compared with MI produced by fluid-present melting of metasedimentary rocks, thus indicating fluid-absent melting. These glasses are also characterized by enrichment of large ion lithophile elements (particularly Cs and Rb), depletion of Ba and Sr, low contents of light rare earth elements (3.6 to 33.7 ppm), high Rb/Sr ratios (6.19-37.3) and low Nb/Ta ratios (2.55-18.7). In combination with phase equilibrium modelling, these compositional features suggest that a sequential dehydration melting of muscovite and biotite was responsible for the production of MI during prograde metamorphism of the studied paragneiss. By compiling MI data published in the literature, we show that dehydration melting of metasedimentary rocks from the Himalayan orogen can produce initial melts with various peraluminous and granitic compositions.