Supporting information

1. Figure S1 The mineral phase maps of the studied orthogneisses and metapelites.

2. Figure S2 Primitive mantle-normalized trace element patterns and chondrite-normalized REE patterns of the studied orthogneisses.

3. Figure S3 Plots of trace elements, and HREE patterns of the detrital zircon core and metamorphic rim from the metapelites.

4. Table S1 Bulk-rock major (wt.%) and trace element (ppm) compositions of the orthogneiss and metapelite from the eastern Gangdese arc.

5. Table S2 Chemical compositions of garnet from the studied orthogneisses and metapelites (wt.%).

6. Table S3 Representative chemical compositions of main minerals from the studied orthogneisses and metapelites (wt.%)

7. Table S4 Parameters and calculation results of the petrophysical properties of metapelites and orthogneisses.

8. Table S5 Zircon U-Pb dating and trace element compositions of the orthogneisses and metapelites.