Supplementary Table 1. Compositional groups, typical sample numbers and location with their bulk compositional, mineralogical and petrographic characteristics at different metamorphic grades. Sample #s, Mineral assemblage, Compositio N/E Traverse, Texture Metamorphic Bulk Chemical mode nal GPS and grade Characteristics and Group coordinates other comments mineral chemistry Ms-Chl-Qtz-Ilm-Mag-Gr ± Kfs ± Pl Mode: (Qtz 35-42%, Ms 30 - 33%, Chl 25 - 30%, Pl 5-7%). #1/00, E, Lithology: Chlorite quartz phyllite (minor white 27 o11.268, mica), white mica quartz phyllite (minor chlorite) /88 o38.581 Two compositional and chlorite bearing quartzite. Millimeter to centimeter groups (one richer in scale banding into M- Al 2O3 ~25 wt.%, Muscovite: domain (mica + chlorite Chlorite Normal #187/01, another ~20 Wt.%). rich), grain size 2 - 20 m 187/3, Rocks richer in Paragonite 5%, Pyrophyllite 19%, Celadonite 12%, and Q - domain (quartz - 187/3/ CHAKRA Al 2O3 are relatively Fe-celadonite 13%. feldspar rich), grain size 10 , N, GPS not less ferruginous (see - 50 µm. known Fig 3). Chlorite: XMg (Mg/(Mg+Fe(tot)) = 0.37 - 0.41. Plagioclase: XAn = 0.03 #ID/00,E, Ms-Chl-Qtz-Bt - Pl ± Ilm ± Tur ± Gr 27 o11.268, /88 o38.581 Chl - Qtz - Ms - Ilm -Gr - Tur - Bt - Pl #2/00, E, Two subgroups - 27 o11.465, high Al, low Fe (18 o /88 38.650 - 24 wt% Al 2O3, - Mode: (Qtz 35-42%, Ms 30 - 33%, Bt 15 - 18%, Chl 4.5-5 wt% Fe 2O3) 10 - 12%, Pl 5-7%). Pervasive foliation defined #3/00, E, and low Al, high Fe by biotite, white mica, o 27 11.465, (14.5 - 17 wt% chlorite and occasional o /88 38.692 Al 2O3, 6.0 - 8.0 wt% Muscovite: ilmenite (S 2) almost parallel Fe 2O3). to compositional banding #4/00, E, Some with high Paragonite 10 -15%, Pyrophyllite 22 - 28%, (S 0). S 2 is crenulated to S 3 27 o11.484, MnO (0.37 - 0.59 Celadonite 6 -9%, Fe-celadonite 6-14%. defned by new generation Biotite Normal o /88 38.858 wt%). SiO 2 variable of biotite, ilmenite and indicating Biotite: elongated quartz in Q - #167/01, N, interbanding of domains. Some coarser o 27 26.092, variable amounts of XMg = 0.38, X Fe = 0.45, X Ti = 0.03, X (AlVi) = 0.14. biotite, chlorite as well as /88 o30.888 psammitic material, plagioclase cross cut all TiO 2 relatively Chlorite: foliations and appear to be #176/01,N, constant (0.55 - 0.8 post-tectonic. o 27 24.809, wt% for most XMg (Mg/(Mg+Fe(tot)) = 0.45. /88 o30.935 samples). Plag: #170/01,N, o 27 24.809, XAn = 0.03 /88 o30.925 Chlorite - quartz - plagioclase ± muscovite Muscovite: Paragonite 7 - 12%, Pyrophyllite 16 - 33%, #1/00/A, E, Celadonite 11 - 13%, Fe-celadonite 12%. Foliation defined by chlorite Magnesian 27 o11.268, and white mica; crenulation (Normal - /88 o38.581 MgO ~ 5 wt%. Chlorite: Biotite by second generation white biotite) mica. XMg (Mg/(Mg+Fe(tot)) = 0.65. Plagioclase: XAn = 0.1 Ms - Chl - Qtz - Pl - Grt - Mag - Ilm - Gr. Garnet: Concentric growth zoned with Mn and Ca decreasing to rim compensated by increase of Fe and Mg. Core: Sps 50 Alm 34 Prp 3Grs 13 150 - 200 µm euhedral garnet porphyroblasts set in Rim: external S 2 fabric defined Sps 20 Alm 63 Prp 07 Grs 10 by white mica. Elongate quartz and opaque Muscovite: inclusions near core of garnet define an internal Mn-rich # 1C/00/3, E MnO ~ 0.4 wt%, ~ Paragonite 14%, Pyrophyllite 15%, Celadonite 6%, fabric (? S ) at high angles (Normal + 27 o11.288, 10 x other bulk 1 Biotite Fe-celadonite 15%. to the external fabric. Grt) /88 o38.619 compositions. Coarse plagioclase as well Chlorite: as later generation of mica and chlorite cut across main XMg (Mg/(Mg+Fe(tot)) = 0.47; Mn-rich with 0.5 - foliation. Quartz is coarse, 0.6 wt% MnO (= 10x other rocks). polygonal in Q-domains and elongate in M-domains. Plagioclase porphyroblasts reverse zoned, unlike in other rocks, from An 26 (core) - An 10 (rim). Ms - Qtz - Chl - Bt ± Pl - Ilm ± Grt ± Gr Mode: (Qtz 26-30%, Ms 35-40%, Bt 8-15%, Chl 8%, Grt 1-3%, Pl 5-8%) Garnet preferentially Garnet: Concentrically zoned, typical core: develops in graphitic Alm Prp Grs Sps , typical rim: 72 05 06 17 schists. S2 defined by Alm Prp Grs Sps . Total range found: Alm 81 05 04 10 68- Muscovite, chlorite and Prp Grs Sps . In rocks without plagioclase, #8/00, E, 80 4-16 6-16 2-17 biotite wrap around garnet garnet is more calcic: 27 o11.616, porphyroblasts. Marked Low alumina as well Alm Prp Grs Sps . /88 o39.131; 65-68 03 18-21 14 decrease in modal Normal as high alumina abundance of chlorite in compositions Biotite at contact with garnet: X = 0.28, X = #158/01, N, Mg Fe garnet rich areas. S often represented; some 0.47, X = 0.01, X = 0.24. 2 27 o27.711, Ti (AlVI) forms sigmoidal inclusion Mn rich and Mg rich /88 o31.400 trails in garnet, some Garnet bulk compositions Ilmenite included in garnet has higher Mn content garnets include an inner found without (= 5 mol% pyrophanite vs. 3mol% in matrix). trail of S that is straight profound effects on 1 and truncated by S . mineral assemblages Chlorite: XMg = 0.36 - 0.39, lower than in lower 2 #24/99/1, N, Aluminous, at these grades. grades. 27 o27.292´, Magnesian bulk high Fe /88 o31.63 compositions (e.g. #19/99) Muscovite: have lower modal abundance of garnet Paragonite 11%, Pyrophyllite 21%, Celadonite 6%, compared to Fe-rich (e.g. Fe-celadonite 6%. #24/99) samples. Plagioclase: XAn = 0.1 Ms - Cld - Qtz - Chl - Bt - Ilm ± Gr ± Grt Chloritoid porphyroblasts Mode: (Qtz 35-40%, Cld 12 - 16%, Grt 4-8%, Chl 8 Similar in Mn and may be aligned along S or #7/00/R4 - 16%, Ms 20 - 22%, Bt 8-10%, Pl 6-10%). 2 even lower in Al S foliation. Ilmenite is & 7/00/R/6, E, 3 content to garnet often included in chloritoid. 27 o11.616, Cld: bearing rocks from In one case chloritoid and Ferruginous /88 o39.131 the same outcrop garnet occur in the same (Normal + X = 0.1 Garnet (e.g. #8/00). Fe/Mg Mg thin section but in different Chltd) ratio - higher Fe domains - chloritoid occurs #135/01, E, Chlorite: contents - favor in more muscovite rich GPS not appearance of domains. There is a single known X = 0.25 chloritoid. Mg chloritoid inclusion in a garnet in #135/01. Biotite: X Mg = 0.39, X Ti = 0.04, X (AlVI) = 0.18. Chl - Qtz - Grt - Pl - Bt - Ap - Ilm Garnet: Alm 80 Prp 12 Grs 04 Sps 04 , even richer in almandine (82) Low at the rim. Chlorite - garnet - #10/00, E, Potassic plagioclase rich rock with 27 o11.628, (semi - Biotite: chlorite and biotite defining /88 o39.459; Garnet pelite) S foliation. Euhedral garnet 2 (Normal - X = 0.28, X = 0.55, X = 0.03, X = 0.14. overprints, and sometimes Mg Fe Ti (AlVI) Musc deflects, this foliation. Chlorite: XMg = 0.36. Plagioclase: XAn = 0.15 - 0.17. Ms - Qtz -St - Pl - Bt - Ilm - Grt Muscovite and biotite define foliation (S2). Mode: (Qtz 35 - 44%, Ms 15 - 17%, Bt 18 -22%, St Sigmoidal inclusion trails of 9 - 11%, Grt 5-10%, Pl 5 - 10%). S2, including ilmenites, within staurolite and garnet. Garnet: Foliation wraps around porphyroblasts. Core: Alm 63 Prp 12 Grs 08 Sps 17 , with well preserved growth zoning. Increase of Mn content at the very rim. #17/00, E, Equivalent of low Staurolite Normal 27 o12.064, alumina pelites from Muscovite: /88 o41.397 lower grades. Paragonite 17%, Pyrophyllite 12%, Celadonite 5%, Fe-celadonite 10%. Biotite: XMg = 0.4, X Fe = 0.42, X Ti = 0.02, X (AlVI) = 0.16. Staurolite: XFe = 0.78. Ms -Bt -Grt -St - Ky - fibrolite -Grt - Ilm – Qtz ± Cld, secondary Chl. Some locations contain abundant and strongly zoned Tur. Garnet: Core: Alm 83 Prp 09 Grs 06 Sps 02 , distinctly poorer in Mn and only weakly zoned Muscovite and biotite (XAlm ~ Xprp ~ 0.02). define S 2, garnet and staurolite include sigmoidal Muscovite: trails of S 2, kyanite is coarse prismatic. Paragonite 18%, Celadonite 4.5%, Rare chloritoid inclusion in Fe-celadonite 7.5%. garnet coexisting with Aluminous staurolite. (Normal + #11/00, E, Staurolite Biotite: Tourmaline can define kyanite) folded inclusion trails in XMg = 0.34, X Fe = 0.45, X Ti = 0.05, X (AlVI) = 0.16. staurolite sometimes. Plagioclase: Fibrolite often surrounds garnet, biotite with ilmenite, XAn = 0.2. can be folded into crenulations occasionally. Staurolite: XFe = 0.82 - 0.86 (included chloritoid has X Fe = 0.85). Ms - Bt - Qtz - Pl - Grt - Ilm Garnet: Abundant garnet and Exceptionally rich in Sps and Grs in plagioclase; in spite of high CaO = 3.7 wt% Core: Al as well as Zn content, Calcic #14/00, E, compared to general Staurolite does not appear, (Normal - 27 o12.174, Staurolite range of 0.15 - 0.52 Alm Prp Grs Sps , indicating that its Staurolite) /88 o41.026 50 09 14 27 %. with well preserved growth zoning. appearance is controlled by Ca (e.g. Spear and others Plagioclase rich in An: 1995). XAn = 0.34 Ms - Qtz -St - Pl - Bt - Ilm - Grt Garnet: Core: Alm 73 Prp 05 Grs 13 Sps 09 , Rim: Alm 84 Prp 10 Grs 5.5 Sps 0.5 . Muscovite: #15/00, E, Mn - poor 27 o12.157, Paragonite 17%, Pyrophyllite 12%, Celadonite 5%, (Normal, /88 o41.137 Fe-celadonite 10%.