Anwesa Banerjee
email: anwesabanerjee91@gmail.com

N Prabhakar
email: prabhakarnaraga@gmail.com

Nicole Sequeira

Nathan Cogné
email: nathan.cogne@univ-rennes1.fr

Abhijit Bhattacharya

Dynamics of Early Neoproterozoic

Keywords: Paleoproterozoic HT-LP anatexis, phengite mica, Early Neoproterozoic LT-HP metamorphism, ADFB-CITZ accretion, subduction polarity reversal, granitoids 1

HAL is

The N/NNE-striking Aravalli Delhi Fold Belt (ADFB) and the E-striking Central Indian Tectonic Zone (CITZ) converge at the Godhra-Chhota Udepur (GC) sector, west-central India. Analyses of mesoscale deformation structures and metamorphic phase equilibria in the basement and supracrustal rocks are integrated with geochronological-geochemical data (accompanying article) to address the dynamics of the Early Neoproterozoic CITZ-ADFB accretion. In the GC sector, ~1.65 Ga granulite facies anatectic gneisses, ~2.5 Ga and 1.03-1.02 Ga granitoids, and greenschist to amphibolite facies allochthonous supracrustal rocks constitute a tectonic mélange (D2 deformation). The lithodemic units are traversed by networks of W/WNW-striking steepdipping transpressional shear zones with sinistral kinematics (D3). The shallow-dipping mélange with top-to-the south kinematics is intruded by post-D2 to syn-D3 0.95-0.93 Ga granitoids. Mn-NCKFMASH P-T pseudosection analyses of the anatectic gneisses with pre-D2 garnet + cordierite-bearing leucosomes suggest the rocks evolved along a clockwise P-T path in the range of 5-6 kbar and 680-720 °C. By contrast, the Early Neoproterozoic (0.95-0.93 Ga) chlorite + phengite (Si up to 3.32 apfu) + clinozoisite + quartz ± biotite ± garnet schists in the mélange attained pre/syn-D2 peak metamorphic conditions (10-12 kbar, 450-500 °C). NCKFMASH pseudosection analyses of the ~0.95 Ga phengite-bearing schists indicate the supracrustal rocks evolved along a high-P, low-T clockwise path; phengite-poor micas defining the D3 fabric (Si up to 3.04 apfu) attest to post-peak decompression in the schists. The ~2.5 Ga ADFB granites accreted with the ~1.65 Ga HT-LP anatectic gneisses, 1.03 Ga granites, and the ~0.95 Ga LT-HP supracrustal rocks of the CITZ during D2 thrusting. The crustal convergence continued with the emplacement of post-D2 0.95-0.93 Ga granitoids that culminated with the nucleation of W/WNW-striking D3 transpressional shear zones. This broad contemporaneity among felsic plutonism, LT-HP metamorphism in the supracrustal rocks, and the D2-D3 shortening are J o u r n a l P r e -p r o o f

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In accretion settings characterized by clockwise low-temperature, high-pressure metamorphic P-T paths, emplacement of felsic magma generally post-dates collision-related thrust fabrics [START_REF] Searle | Shisha Pangma leucogranite, south Tibetan Himalaya: field relations, geochemistry, age, origin, and emplacement[END_REF][START_REF] Kuster | Post-collisional potassic granitoids from the southern and northwestern parts of the Late Neoproterozoic East African Orogen: a review[END_REF]. These granitoids commonly originate due to decompression of the thickened orogen either by tectonic denudation and/or gravitational collapse [START_REF] Kuster | Post-collisional potassic granitoids from the southern and northwestern parts of the Late Neoproterozoic East African Orogen: a review[END_REF]. These processes, in turn, are ultimately traced to slab delamination [START_REF] Meissner | Weakness of the lower continental crust: a condition for delamination, uplift, and escape[END_REF], trench retreat [START_REF] Jolivet | Cenozoic geodynamic evolution of the Aegean[END_REF], lithospheric thinning [START_REF] Kuster | Post-collisional potassic granitoids from the southern and northwestern parts of the Late Neoproterozoic East African Orogen: a review[END_REF] and subduction polarity reversal involving slab breakoff [START_REF] Willett | Subduction of Asian lithospheric mantle beneath Tibet inferredfrom models of continental collision[END_REF][START_REF] Wang | A neoarchean subduction polarity reversal event in the North China Craton[END_REF].

In the accompanying article (Banerjee et al., 2022a), which develop on the findings of [START_REF] Banerjee | Tectonics of the Greater India Proterozoic Fold Belt, with emphasis on the nature of curvature of the belt in west-central India[END_REF][START_REF] Banerjee | Early Neoproterozoic tectonics in the Godhra -Chhota Udepur sector: Evidence for two-stage accretion in the Greater India Proterozoic Fold Belt (GIPFOB)[END_REF], the Godhra-Chhota Udepur (GC) sector is demonstrated to be a unique crustal domain where two regional orogenic belts in the Indian Peninsula are juxtaposed, i.e., the E-striking Central Indian Tectonic Zone (CITZ) comprising the Chottanagpur Gneiss Complex (CGC) and the central and southern parts of the Satpura Mobile Belt (SMB) are juxtaposed against the N/NNE-striking Aravalli Delhi Fold Belt (ADFB) (Fig. 1). Such a unique juxtaposition of major orogenic belts (cf. [START_REF] Goscombe | Deformation correlations, stress field switches and evolution of an orogenic intersection: The Pan-African Kaoko-Damara orogenic junction, Namibia[END_REF]) is yet to be documented in Peninsular India. In this sector, Archean (~2.5 Ga) and Late Mesoproterozoic (~1.05 Ga) granitoids, Late Paleoproterozoic (~1.65 Ga) anatectic gneisses (archetypal of the CITZ; Banerjee et al., 2022a, b) and allochthonous ~0.95 Ga supracrustal rocks of J o u r n a l P r e -p r o o f Journal Pre-proof greenschist/amphibolite facies are tectonically juxtaposed into a shallow-dipping tectonic mélange. The mélange was intruded by extensive 0.95-0.93 Ga calc-alkaline S-type granitoids, and some were contemporaneous along a network of basement piercing steep-dipping E-trending transpressional shear zones (accompanying article; Banerjee et al., 2022a). These magmatic and deformational events occurred during oblique NNE-SSW convergence (1. between the CITZ and the ADFB.

Based on the structural, chronological and geochemical findings in the GC sector located at the western end of the CITZ, Banerjee et al. (2022a, b) demonstrate that the NNE-striking Aravalli-Delhi Fold Belt terminated against the E-striking CITZ at ~1.0 Ga. In this article, we document the metamorphic evolution of the interleaved supracrustal rocks and the Late Paleoproterozoic CITZ gneisses in the tectonic mélange in the GC sector, and integrate the findings of Banerjee et al. (2022a, b) to evolve a geodynamical model for the Neoproterozoic accretion event. This study of Early Neoproterozoic accretion is vital since the CITZ has been correlated with several regional scale accretion orogens across drifted continental blocks (summarised in [START_REF] Banerjee | Tectonics of the Greater India Proterozoic Fold Belt, with emphasis on the nature of curvature of the belt in west-central India[END_REF].

GEOLOGICAL BACKGROUND

Based on the recent findings [START_REF] Banerjee | Tectonics of the Greater India Proterozoic Fold Belt, with emphasis on the nature of curvature of the belt in west-central India[END_REF](Banerjee et al., , 2022a, b), b), we highlight the lithological and mesoscale structural aspects of the basement gneisses and the supracrustal rocks relevant to this study. The majority of the basement gneisses are anatectic, especially in the south-central parts of the GC sector. These gneisses with metatexite layers occur as mesoscale enclaves within granitoids; in the absence of regional-scale outcrops, the areal extent of the gneiss exposures cannot be shown in Fig. 1a. The field occurrences of these gneisses in relation to other

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Journal Pre-proof lithodemic units are depicted in the 3-dimensional sketch of the overall structural setting in the GC sector (Fig. 1b). These anatectic gneisses are of two mineralogical types. In mesocratic anatectic gneisses, the mineral segregation banding (gneissic layering) is defined by quartz + plagioclase + K-feldspar bearing leucosome layers and biotite + hornblende dominated mesocratic layers that also contain quartz and feldspar in subordinate amounts. Ilmenite, sphene, apatite, monazite and rare zircon are accessory phases, mostly in the mesocratic layers/matrices. These gneisses are non-garnetiferous, in contrast to the melanocratic gneisses in which garnets are ubiquitous and profuse (Fig. 2a,b). In the melanocratic gneisses, the garnet porphyroblasts, rarely larger than 6 mm diameter, occur both within the leucosome layers (Fig. 3a) and in the foliated melanocratic matrix dominated by biotite, quartz, plagioclase, with subordinate amounts of cordierite and sillimanite (Fig. 2b). Garnets are also common within biotite-rich selvages at the leucosome-melanosome interfaces (Fig. 2a).

The leucocratic layers in both types of gneisses exhibit tight to isoclinal folds that exhibit thickened hinges and attenuated limbs; the limbs are commonly boudinaged and exhibit pinch and swell structures (Fig. 3a). In the hinge zone of these isoclinal folds, vestiges of an earlier schistosity, especially well-developed in the melanocratic gneisses, mimic the hinges. These folds are intrafolial to the penetrative foliation, which in turn is parallel to the distended limbs of the isoclinal folds. We infer the composite of folded leucosome layers and biotite segregations formed due to D1a deformation, and the later penetrative fabric to be a manifestation of D1b deformation. In zones for high D1b strain, the former D1a schistosity is preserved as mineral inclusion trails in garnet porphyroblasts oblique to the warping D1b fabric (Fig. 2b). Profuse melting (as in metatexite) mark the pre-to syn-D1a deformation stage (Fig. 3a), but syn-to post-D1b melts are lacking or are extremely limited [START_REF] Banerjee | Early Neoproterozoic tectonics in the Godhra -Chhota Udepur sector: Evidence for two-stage accretion in the Greater India Proterozoic Fold Belt (GIPFOB)[END_REF].

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The D1a-D1b composite foliation describes recumbent to gently-inclined D2 folds (Fig. 3b) that plunge W/WNW, broadly parallel to the stretching lineations in the pre-D2 granitoid mylonites [START_REF] Banerjee | Early Neoproterozoic tectonics in the Godhra -Chhota Udepur sector: Evidence for two-stage accretion in the Greater India Proterozoic Fold Belt (GIPFOB)[END_REF]. These folds formed due to top-to-the-south D2 thrusting (Fig. 3c) are superposed by W/WNW-trending open, upright to steeply inclined, and gentle to moderately plunging folds (D3 deformation). These folds are associated with a network of W/WNW-striking steep-dipping transpressional shear zones with sinistral kinematics. The hinges of the D3 folds are collinear with the D3 stretching lineations in the post-D2 and syn-D3 granitoid mylonites [START_REF] Banerjee | Early Neoproterozoic tectonics in the Godhra -Chhota Udepur sector: Evidence for two-stage accretion in the Greater India Proterozoic Fold Belt (GIPFOB)[END_REF].

The supracrustal rocks are exposed in several parts of the GC sector (Fig. 1a,b). The rocks comprise meta-oligomict conglomerate, meta-arenite, micaceous quartzite (quartz, white mica, chlorite), mica schist (white mica, chlorite, quartz, ± clinozoisite/epidote ± biotite ± garnet), metacarbonates (calcite, dolomite, quartz, tremolite, talc, antigorite, clinopyroxene) and Mn-rich horizons, amphibolite (hornblende, actinolite, plagioclase, quartz and clinozoisite). In the ultramafic rocks in the NE of Jobat (Fig. 1a), chlorite, tremolite and Al-poor orthoamphiboles replace embayed grains of relic Mg-rich olivine and pyroxenes (not reported here). The amphibolites are commoner in the northern parts in Fig. 1a. The poly-deformed supracrustal rocks were considered to share an unconformable relation with the basement anatectic gneisses and granitoids [START_REF] Heron | Geology of Aravalli Fold Belt[END_REF]. We observe the basement-cover contact wherever exposed is shallow-dipping and intensely mylonitized; the conglomerate layers in the supracrustal rocks are intra-formational, and no persistent basal conglomerate horizon separates the supracrustal rocks from the underlying basement rocks.

The earliest recognisable fabric in the supracrustal rocks is a colour banding observed in meta-dolomites, marbles and micaceous quartzites. These colour bands, in quarry faces, exhibit J o u r n a l P r e -p r o o f Journal Pre-proof sharp hinged isoclinal folds (D1 deformation). The axial traces of the D1 folds are defined by white mica-chlorite aggregates in mica schists, talc-tremolite antigorite in meta-carbonate rocks and hornblende-plagioclase-clinozoisite/epidote in amphibolites. The D1 schistosity commonly exhibits recumbent to gently-inclined folds and shallow-dipping shear zones (D2 deformation).

The D2 folds are round-hinged and isoclinal in metarenites, sharp hinged in metacarbonates and micaceous quartzites (Fig. 3e), and largely obliterated in mica schists. Rootless hinges of the folded D1 schistosity and curved traces of D1 schistosity in D2 microlithons are common in mica schists. The D2 folds are gently-plunging and the axial plane schistosity to D2 folds are spaced and/or zonally developed in the quartzites/meta-renites and meta-carbonates, but is the most penetrative fabric in the mica schists and amphibolites, except in domains of high D3 strain manifested by W/WNW-striking sinistral shear zones. In these D3 domains, open, upright to steeply-inclined folds with gentle to moderately plunging W/WNW-trending hinge lines in the supracrustal rocks (Fig. 3f,g) the D3 fabrics are transposed to D3 schistosity.

PETROGRAPHY AND MINERAL CHEMISTRY

In this section, we present a broad framework of the mineralogy in the allochthonous supracrustal unit and the anatectic basement gneisses. Subsequently, detailed paragenetic relations are presented for selected lithologies and examined in detail for the reconstruction of metamorphic P-T paths. These paths are combined with chronologic and geochemical information in gneisses and granites (accompanying article, Banerjee et al., 2022a) to reconstruct the dynamics of the crustal accretion process. The samples analysed are metacarbonates (AW 70B, AW 157B), mica schists (AW 46B, AW 91, AW 44, AW 82A) and amphibolite (AW 45) in the supracrustal unit, and garnet-cordierite-sillimanite bearing biotite-rich anatectic gneisses J o u r n a l P r e -p r o o f Journal Pre-proof (AW 142A, AW 372) from the basement rocks (Fig. 2). The protocol for determining mineral compositions by Electron Probe Micro Analyzer (EPMA) is in the Appendix A.

Metacarbonates (AW 157B, AW 70B)

The metacarbonates are dominantly of two mineralogical varieties, e.g., those containing calcite, dolomite, talc, tremolite, chlorite ± kaolinite in the eastern part (represented by AW 70B), and clinopyroxene, plagioclase, calcite, dolomite, quartz and forsterite (pseudomorphed by serpentine) in the western part (represented by AW 157B). The Mn-rich horizons [START_REF] Das | A preliminary study of thermal metamorphism in the Champaner Group of rocks in Panchmahals and Vadodara districts of Gujarat[END_REF] within the supracrustal unit are excluded.

In the tremolite-talc metacarbonates, the D2 and D3 fabrics are defined by the shape preferred aggregates of talc, tremolite, chlorite and rare kaolinite in a fine-grained recrystallized mosaic of calcite>>dolomite and quartz (Fig. 4a). Tremolite (and talc) also occurs as randomlyoriented post-D3 porphyroblasts (measuring up to couple-of-cms long) and are commonly sievetextured due to profuse inclusions of quartz, calcite and dolomite (Fig. 4b). In sample AW 70B (Mineral data in Supplementary Material 1 ), the MgO contents in dolomite lie between 19.4 and 23.8 wt%; the corresponding values in calcite are < 0.2 wt%. Following the classification of [START_REF] Leake | Nomenclature of amphiboles; report of the Subcommittee on Amphiboles of the International Mineralogical Association Commission on new minerals and mineral names[END_REF], the clinoamphiboles straddle the boundary between tremolite and actinolite with X Fe [=Fe 2+ /(Fe 2+ +Mg)] values between 0.06 and 0.10. In the sample, talc and chlorite are

Mg-rich [X Fe

Chl is in the range 0.08-0.09, and X Fe Tlc lies between 0.04-0.05].

In the calcite-clinopyroxene-plagioclase bearing metacarbonate AW 157B (mineral data in Supplementary Material 1 ), the D2 mineral segregation is defined by the alternation of recrystallized aggregates of clinopyroxene-talc-biotite rich (with subordinate amounts of calcite and dolomite) layers and calcite-dolomite-quartz rich layers (Fig. 4c,d). Detailed EPMA data were obtained for four mica schists with somewhat variable mineral assemblages (Tables 123), e.g., a garnet-bearing white mica-chlorite-quartz-plagioclasebiotite-ilmenite-magnetite schist (AW 91), a white mica-chlorite-quartz-clinozoisite-plagioclasebiotite-magnetite schist (AW 46B) and a white mica-quartz-chlorite-plagioclase-clinozoisitesphene-ilmenite schist (AW 44) were selected from the eastern part of the GC sector; and a white mica-chlorite-quartz-plagioclase-clinozoisite-biotite-tourmaline schist (AW 82A) was considered from the western part in the GC sector (Fig. 1a).

J o u r n a l P r e -p r o o f AW 44 is a mica schist form D3 low strain domain. The D2 schistosity in the white micachlorite-quartz schist is crenulated; the D3 crenulation cleavages are locally developed, and are defined by the same set of minerals (Supplementary Material 3 ). Modally subordinate proportion of clinozoisite is restricted to the plagioclase-quartz D2 microlithon. Plagioclase is chemically zoned neighboring the clinozoisite grain aggregates. Sphene occurs as aggregates of discrete grains. In the sample, ilmenite is the only Fe-Ti oxide phase, and occurs as an accessory phase (<1 volume %).

The garnet-free mica schist (AW 46B) occurs as couple of cm-wide layers interleaved with steep-dipping foliated quartzites and meta-arenites in a road cut section. In the outcrop, the mica schist exhibits asymmetric D3 crenulations that are locally transposed to D3 schistosity (Fig. 3g). The crenulated D2 layers are defined by shape-preferred aggregates of white micachlorite that alternate with quartz ± plagioclase layers (Fig. 5a). The D3 schistosity is disjunctive, anastomosing and defined by the same set of minerals (Fig. 5a,b). In the D2 quartz microlithons, a pre-D2 tectonic fabric oblique to the warping D2 foliation is also defined by aggregates of chlorite-white mica (Fig. 5b). Clinozoisite occurs in quartz-plagioclase D2 microlithons and as post-D3 porphyroblasts (Fig. 5c). Biotite is an accessory mineral either interleaved with D3 white mica-chlorite aggregates or occurring as discrete post D3 porphyroblasts.

The garnet-bearing mica schist AW 91 exhibits a penetrative steep-dipping spaced, somewhat anastomosing crenulation cleavage (D3) defined by white mica-chlorite layers that alternate with quartz-rich layers containing minor proportion of plagioclase. Garnet occurs in the D3 chlorite-rich domains as small (~200μm diameter) xenoblastic porphyroblasts (Fig. 6a). The rare garnet porphyroblasts appear to overgrow the D2 fabric. but are wrapped by the D3 fabric (Fig. 6a).

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The sample AW 82A is a white mica-chlorite-quartz-tourmaline bearing schist with rare post-D2 biotite, and occurs interleaved with an intensely sheared (D2) oligomict quartz pebble conglomerate. Tourmaline and sphene occur as accessory phases in the rock. The penetrative steep-dipping fabric is defined by white mica-chlorite aggregates that alternate with quartz-rich domains. The penetrative D2 fabric defined by the same mineral phases is evident in the D3 intrafolial domains.

The variations in the white mica compositions in the samples AW 44, AW 46B, AW 91 and AW 82A are as follows: Si: 3.14-3.29 apfu; Si: 3. [=Na/(Na+K)]: 0.04-0.06, 0.03-0.06, 0.03-0.17 and 0.03-0.06 (Table 1). Taken together, the corresponding values for the three samples are: Si = 3.04-3.27 apfu; Si/Al = 1.09-1.38; X Mg = 0.23-0.54; and X Na = 0.03-0.17. In each of the samples, several spots in quartz were analyzed to ascertain that the Si abundances in the white micas were not overestimated (Table 1).

The white micas turned out to be phengitic in composition, and in the Na-free system is limited by the compositions of the end member components muscovite [KAl 2( AlSi 3 )O 10 (OH) 2 ]

and celadonite [K(Mg,Fe)(Al)(Si) 4 O 10 (OH) 2 ] components; the two phase components are related by the exchange vector Al (VI) + Al (IV) → Si 4+ + (Fe 2+ , Mg 2+ ) [START_REF] Cibin | The octahedral sheet of metamorphic 2 M 1-phengites: a combined EMPA and AXANES study[END_REF]. This is the first report of the occurrence of phengite mica from the supracrustal rocks in the GC sector in particular, and the Satpura Mobile Belt and the Chottanagpur Gneiss Complex along the Estriking CITZ (Fig. 1), in general.

The compositions of white mica in the samples AW 44, AW 46B, AW 91 and AW 82A

were compared with published compositions of white micas in high-pressure mica schists J o u r n a l P r e -p r o o f

Journal Pre-proof elsewhere (Fig. 5d,e). The compositions of our samples overlap with the existing data. In the (Fe 2+ + Mg) vs Si plot (Fig. 5d), the phengite compositions extend from the muscovite end member composition (Fe 2+ + Mg = 0; Si = 3) towards the celadonite end member (Fe 2+ + Mg = 1; Si = 4) along the tschermakite substitution vector. Also, in the Al vs Si plot (Fig. 5e), the white micas define a linear trend similar to phengites from other high-pressure rocks collated from elsewhere. The low Ti (0.01-0.03 wt%) and X Na values in the phengites from our samples are also in accord with the samples from around the world, and are indicative of low-temperature, high-pressure (LT-HP) metamorphism [START_REF] Auzanneau | Titanium in phengite: a geobarometer for high temperature eclogites[END_REF].

However, for any sample, the Si, Al, Fe and Mg contents in the white micas vary considerably (Table 1, Figs. 5d,e). Several authors demonstrably argue that the phengite content in white mica increases with increasing pressure (Krogh and Raheim, 1978;[START_REF] Green | Fe-Mg partitioning between coexisting garnet and phengite at high pressure, and comments on a garnet-phengite geothermometer[END_REF]Massone and Schreyer, 1987; among others). In other words, higher abundances of Si, Fe and Mg, and lower Al contents in phengite-richer micas are stable at higher pressure. The variations in our samples could result from chemical zoning in Si, Al, Fe and Mg in individual grains of white mica. Alternately the abundances of the elements could vary depending on the textural setting (multiple deformation fabrics) of white micas in the samples. X-ray element maps for the four elements could not be performed on the finely-interleaved individual grains because the micas were not wide enough for resolving the differences in the element abundances.

But wider area high-resolution X-ray maps of Si, Al and Fe (Fig. 5f) were prepared to examine if the white micas defining the different sets of fabrics (i.e., D2 and D3) have different compositions. Several such maps -including maps for K (Fig. 5f) to rule out the presence of quartz and chlorite -exhibit that the white micas defining the D3 fabric are characterized by lower abundances of Si and Fe, and higher abundances of Al relative to those that define the D2

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X-ray elemental maps for Ca, Fe, Mg, and Mn were acquired on one of the two garnet grains in the mica schist AW 91 (Fig 6b,c). Chemical zoning in the garnet (Alm 64-71 Prp 5-10 Grs 16-17 Sps 16-11 ; Table 2) is patchy, with no well-defined core and rim regions (Fig. 6b). However, rim to rim compositional gradient exists, e.g. X Fe and X Mg increase towards the D3 chlorite aggregates, with a complementary decrease in X Mn [where X i = i/(Fe 2+ + Mg + Ca + Mn; where i = Fe 2+ , Mg, Mn and Ca]; grossular contents vary within 1 mol% (Table 2; Fig. 6c).

Plagioclase in the mica schists is albite in composition, e.g., X Ab [= Na/(Na + Ca + K)] ranges between 0.96 and 0.98 for AW 46B and AW 91, respectively (Table 2). In AW 44, the X Ab varies between 0.85 and 0.90. The Na-rich compositions are obtained in plagioclase mantles neighbouring clinozoisite grain aggregates, whereas the clinozoisite-free parts are more Caricher.

The composition of biotite in the mica schists is tightly constrained, e.g. X Fe Bt (= Fe 2+ /Fe 2+ + Mg) lies in the range 0.52-0.54 for AW 46B and 0.57-0.59 for AW 91 (Table 2).

X Fe Chl (= Fe 2+ /Mg + Fe 2+ ) in AW 91 varies between 0.57 and 0.61; in AW 46B chlorite is less ferroan and range between 0.48 and 0.52 ( 2).

Amphibolite (AW 45)

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The amphibolite interleaved with mica schists in the supracrustal unit is dominated by Al-rich amphiboles [ferro-tschermakite to ferro-hornblende] and actinolite, and plagioclase (albite) in sub-equal modal amounts; clinozoisite and quartz together constitute upto 15 vol% of the rock, and sphene occurs locally within amphiboles (<3 vol%). Chlorite is a minor mineral (<2 vol%).

Nomenclature of amphiboles is after [START_REF] Leake | Nomenclature of amphiboles; report of the Subcommittee on Amphiboles of the International Mineralogical Association Commission on new minerals and mineral names[END_REF]. The rock exhibits two metamorphic fabrics; the penetrative S2 cleavage curves into and is transposed along a spaced S3 cleavage (Fig. 4e,f). Both the D2 and D3 fabrics in amphibolites are defined by the shape-preferred aggregates of co-existing Al-rich and Al-poor clinoamphiboles (Fig. 4e,f). In both fabrics, the amphiboles are intergrown with prismatic crystals of clinozoisite and lentils of plagioclase and quartz ribbons. The clinozoisite grains within the xenoblastic plagioclase grains constitute linear arrays defining the S2 schistosity (Fig. 4f) and exhibit ink-blue interference colour. The clinozoisite grains neighbouring the amphiboles exhibit yellow, first-order red to orange interference colours (Fig. 4f). The colour variation in clinozoisite is a manifestation of their Fe contents; Fe# (calculated as Fe 3+ /(Fe 3+ +Al 3+ )) for the clinozoisite neighbouring amphiboles are higher and range from 0.12-0.15 while that for the clinozoisite within plagioclase lie between 0.06-0.09. Sphene occurs as discrete grains as well as grain aggregates within the clinoamphiboles.

X Fe [=Fe 2+ /(Fe 2+ +Mg)] in the Al-rich and the Al-poor amphiboles vary in the range 0.51-0.57 and 0.36-0.38, respectively (Supplementary Material 2 ). In the amphiboles, Fe J o u r n a l P r e -p r o o f

Anatectic basement gneiss (AW 142A, AW 372)

The D1a-1b composite layering in biotite-rich gneisses consists of two major parts (Fig. 2a). The melanocratic mosaic in AW 142A (Fig. 2a) and AW 372 (Fig. 2b) is dominated by biotite in a dynamically recrystallized mosaic of quartz and plagioclase, with subordinate amounts of garnet, K-feldspar, cordierite, and sillimanite. The leucocratic part, on the other hand, is dominated by quartz, plagioclase, and modally subordinate amounts of biotite, garnet (Fig. 2a), and rare cordierite (Fig. 2c). K-feldspar is rare in the leucocratic part in Fig. 2a. Garnet and cordierite, (Fig 2c) hosted within leucosomes share stable (non-reactive) boundaries with the associated plagioclase and quartz. Dark selvages of biotite, coarser-grained than the melanocratic mosaic, and strongly embayed garnets occur along the margin of the leucosome layers (Fig. 2a). The biotite flakes in the selvages exhibit well-developed biotite-defined fabric (D1b) that overprint, and commonly obliterate, the asymmetrically folded former D1a biotite-defined foliation (Fig. 2a). The garnet porphyroblasts in the selvages in AW 142A (Fig. 2a) contain inclusions of biotite, cordierite, plagioclase, quartz and rare sillimanite grains (Fig. 2d). The garnets, in turn, are mantled by double-layered corona, with plagioclase forming the inner collar and aggregates of randomly-oriented biotite grains dominating the outer collar. Randomly oriented chloritemuscovite intergrowths (Fig. 2e) replace biotite-plagioclase aggregates in the leucosome.

Ilmenite, apatite, monazite and rare zircon occur as accessory minerals.

The metamorphic textures in the melanosome are better preserved in the mineralogically homogenous matrix in AW 372 (Fig. 2b), which is mineralogically and chemically similar to AW 142A. The prominent fabric D1b in AW 372 (Fig. 2b) is defined by the aggregates of shape preferred biotite, sillimanite and quartz lentils in a recrystallized mosaic of quartz > plagioclase >

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Journal Pre-proof K-feldspar. The D1b fabric wraps around the larger garnet porphyroblasts (Fig. 2b). The larger porphyroblasts, mostly pre-tectonic with respect to the D1b fabric, comprises two parts. The garnet interiors, especially in the coarse grains, exhibit straight to mildly curved trails (D1a) of inclusions of quartz, sillimanite, biotite, and minor proportions of cordierite and feldspars (Fig. 2f). The inclusion trails are oblique and oriented at similar angle to the D1b fabric. The interiors of these garnets are bordered by inclusion-free/poor mantles that, at places, overgrow the D1b fabric. In the smaller garnets, the D1a inclusion trails are either lacking or ill-defined, the porphyroblasts are post-D1b, and sub-idioblastic (Fig. 2g) as opposed to the xenoblastic and skeletal nature of the larger garnets (Fig. 2e). The smaller sub-idioblastic garnets lie almost entirely within biotite aggregates, and appear to overgrow the D1b fabric. As with the coarse garnets, the post-D1a, pre-D1b idioblastic cordierite porphyroblasts also contain inclusion trails of sillimanite and quartz (Fig. 2h). These inclusion trails in the cordierite are oriented subparallel to the inclusion trails within the coarse garnet porphyroblasts (Fig. 2b). The coarser garnets are partly or wholly mantled by continuous rims of anhedral cordierite grains (Fig. 2b,f), distinct from the matrix cordierites that occur as idioblastic grains. Strongly embayed grains of garnet, sillimanite and biotite occur as rafts within these post-D1b cordierite grains mantling the garnets. However, the smaller post-D1b garnet grains (Fig. 2g) are not mantled by cordierite.

The biotite-rich melanocratic gneisses, in general, and AW 142A and AW 372 in particular, do not contain sphene and Fe-Ti oxide phases (Fig. 2a,b). However rare grains of pyrite occur as an accessory phase in these gneisses.

Summary of EPMA data of minerals in AW 142A and AW 372 are provided in Supplementary Material 4,5 . Histograms in Supplementary Material 6 show compositional variations in biotite and plagioclase across the melanosome, leucosome layers and the biotite-J o u r n a l P r e -p r o o f garnet X i is defined as X i = i/(Fe+Mg+Ca+Mn), where i = Fe 2+ , Mg, Mn and Ca. X Fe Bt and Ti (apfu) in all biotite grains taken together lie in the range 0.52-0.56 and 0.10-0.17 respectively.

No differences in X Fe Bt and Ti Bt (apfu) are evident across the three domains, although biotite in the leucosomes tends to have higher X Fe Bt values. Plagioclase in the three domains is andesine in composition, i.e., 36-42 An mol%; plagioclase compositions in the leucosome are in the range 36-40 mol% An, whereas An contents in melanosome are more sodic, i.e., >38 mol%. The compositions of cordierite and chlorite are tightly constrained, e.g., X Fe Crd across the three domains and X Fe Chl in the melanosome vary in the ranges 0.36-0.38 and 0.37-0.51 respectively.

In AW 372, the Mn content of the ferromagnesian minerals are slightly higher than in AW 142A

(Supplementary Material 4,5 ); plagioclase in AW 372 is andesine in composition.

The almandine-pyrope garnet porphyroblasts, with subordinate fractions of spessartine and grossular, in both samples are chemically zoned (Fig. 7a-c). in AW 372 (Fig. 7).

In both the samples, fibrolitic and randomly-oriented rare intergrowths of white mica, chlorite and paragonite (Supplementary Material 4,5 ) replace plagioclase, biotite and cordierite (Fig. 2e). The important chemical features in these white micas are the following, e.

METAMORPHIC P-T CONDITIONS

Bakker and [START_REF] Bakker | Fluid inclusions as metamorphic process indicators in the Southern Aravalli Mountain Belt (India)[END_REF] and [START_REF] Das | A preliminary study of thermal metamorphism in the Champaner Group of rocks in Panchmahals and Vadodara districts of Gujarat[END_REF] provide information on the metamorphic conditions in the Precambrian rocks from the Southern Aravalli Mountain Belt of which the GC sector is the southernmost part. Based on fluid inclusion studies in quartz and conventional thermo-barometry, [START_REF] Bakker | Fluid inclusions as metamorphic process indicators in the Southern Aravalli Mountain Belt (India)[END_REF] determined P-T conditions of 2-1.5 kbar and 600-620 °C for metamorphism in the biotite-garnet schists from the Lunavada Supergroup (sample locations unknown). According to [START_REF] Das | A preliminary study of thermal metamorphism in the Champaner Group of rocks in Panchmahals and Vadodara districts of Gujarat[END_REF], the greenschist facies supracrustal rocks of the Champaner Group (in the GC sector) experienced Early Neoproterozoic thermal metamorphism induced by the emplacement of the ~0.95 Ga Godhra granite; however, no quantitative P-T estimates were provided by the authors. In this section, we provide metamorphic P-T conditions (Fig. 8) and metamorphic P-T path reconstructions from the mica schists (AW 46B, 91; Fig. 9) and an amphibolite (AW 45) in the 1.03-0.95 Ga supracrustal unit, and 1.7-1.6

Ga anatectic biotite-sillimanite-garnet-cordierite gneisses (AW 142A,AW 372;Figs. 10,11).

Sample locations are in

. Supracrustal unit

The P-T estimates for the supracrustal rocks are obtained in white mica-chlorite schists AW 46B

and AW 91 (Fig. 8a), and an amphibolite AW 45 (Fig. 8b). For the mica schists, temperatures were estimated using the thermometers garnet-phengite (Krogh and Raheim, 1979;[START_REF] Green | Fe-Mg partitioning between coexisting garnet and phengite at high pressure, and comments on a garnet-phengite geothermometer[END_REF], biotite-muscovite [START_REF] Hoisch | A muscovite-biotite geothermometer[END_REF], biotite-muscovite-chlorite [START_REF] Powell | A new geobarometer for the assemblage biotite-muscovite-chlorite-quartz[END_REF]) and garnet-biotite [START_REF] Ferry | Experimental calibration of the partitioning of Fe and Mg between biotite and garnet[END_REF][START_REF] Perchuk | Correction of the biotite-garnet thermometer in case of the Mn=Mg+Fe isomorphism in garnet[END_REF][START_REF] Perchuk | Experimental investigation of exchange equilibria in the system cordierite-garnet-biotite[END_REF][START_REF] Bhattacharya | Non-ideal mixing in the phlogopite-annite binary: constraints from experimental data on Mg-Fe partitioning and a reformulation of the biotite-garnet geothermometer[END_REF][START_REF] Kaneko | Recalibration of mutually consistent garnet-biotite and garnetcordierite geothermometers[END_REF][START_REF] Holdaway | Garnetbiotite geothermometry revised: new Margules parameters and a natural specimen data set from Maine[END_REF][START_REF] Holdaway | Application of new experimental and garnet Margules data to the garnetbiotite geothermometer[END_REF][START_REF] Hodges | Geothermometry, geobarometry and the Al2SiO5 triple point at Mt Moosilauke, New Hampshire[END_REF][START_REF] Indares | Biotite-garnet geothermometry in the granulite facies: the influences of Ti and Al in biotite[END_REF][START_REF] Ganguly | Mixing properties of aluminosilicate garnets: constraints from natural and experimental data, and applications to geothermo-barometry[END_REF][START_REF] Perchuk | Precambrian granulites of the Aldan shield, eastern Siberia, USSR[END_REF]William and Grambling, 1990;[START_REF] Hoinkes | Effect of grossular-content in garnet on the partitioning of Fe and Mg between garnet and biotite-an empirical investigation on staurolite-zone samples from the Austroalpine Schneeberg complex[END_REF]. Pressures were estimated from the garnet-muscovite-plagioclase-quartz (GMPQ; [START_REF] Hoisch | Empirical calibration of six geobarometers for the mineral assemblage quartz+ muscovite+ biotite+ plagioclase+ garnet[END_REF] and garnet-biotite-muscoviteplagioclase-quartz (GBMPQ; [START_REF] Hodges | Error estimation and empirical geothermobarometry for pelitic systems[END_REF][START_REF] Hoisch | Empirical calibration of six geobarometers for the mineral assemblage quartz+ muscovite+ biotite+ plagioclase+ garnet[END_REF] barometers. The garnetbiotite thermometers yield temperatures in the range 420-500 °C; while garnet-phengite thermometers yield somewhat higher temperatures, 470-550 °C (all T values rounded to nearest ten). The biotite-muscovite thermometers yield temperatures in the range 530-650 °C. Pressure estimates obtained from the GBMPQ and GMPQ barometers for phengite-rich muscovite yield high pressures, 10-15 kbar in the temperature range 500-550 °C. The biotite-muscovite-chlorite equilibrium [START_REF] Powell | A new geobarometer for the assemblage biotite-muscovite-chlorite-quartz[END_REF]) was applied to both the mica schist samples for the entire range of Si contents in the samples (Si: 3.08-3.27 apfu in AW 46B, and Si: 3.10-3.24 apfu for AW 91) to calculate the lnKd values using the formulations of the authors. The P-T loci for the barometric formulation for the different lnKd values (Fig. 8a) correspond to the whole range of Si contents in the phengites from the samples. Since the compositions of chlorite and plagioclase in each of the samples are similar, the wide variation in pressure at any temperature is a function

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Journal Pre-proof of the Si contents of the white micas. Clearly, the highest pressure in each sample is obtained for the micas with the highest celadonite component. In other words, phengite richer D2 micas equilibrated at a high pressure relative to the micas defining the D3 fabrics (Fig. 5f). Based on the results of the thermo-barometric computations, the P-T box (Fig. 8a) deduced from the intersections of the mineral thermo-barometers involving phengite-rich mica assemblages is our preferred estimate of the peak P-T conditions experienced by the mica schists. The preferred P-T conditions (12 ± 1.5 kbar, 500 ± 50 °C) fall in the kyanite stability field (Fig. 8a).

In the amphibolite AW 45, temperatures were obtained using the Al-rich amphiboleplagioclase thermometers of [START_REF] Blundy | Calcic amphibole equilibria and a new amphibole-plagioclase geothermometer[END_REF] and [START_REF] Holland | Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry[END_REF]. In the calculations, the cation site allocations for amphiboles were done as per Appendix B of [START_REF] Holland | Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry[END_REF]. The two thermometers (T a and T b ) followed by [START_REF] Holland | Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry[END_REF] are based on the reactions edenite + 4quartz = tremolite + albite and edenite + albite = richterite + anorthite, respectively. The T a thermometer of Holland and Blundy (1994) yields higher

temperatures (580-720 °C) compared to the T b thermometric formulation (400-600 °C). The pressure conditions were estimated for AW 45 using the plagioclase-hornblende-quartz barometer of Bhadra and Bhattacharya (2007). The magnesiohornblende compositions yield pressure between 4.4 and 6.0 kbar at 550 °C; by comparison, the ferrohornblende and ferrotschermakite compositions yield larger variations in P values in the range 3.8-7.1 kbar at T = 550 °C. The intersections of the thermo-barometers yield two P-T boxes, e.g., 450 ± 30 °C, 5 ± 2 kbar corresponding to the T a thermometer and 650 ± 50 °C, 8 ± 2 kbar corresponding to the T b thermometer.

The difference (~200 °C) in temperature between the T a and T b may stem from the fact that the temperatures are calculated from reactions that involve low-Al end member components

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Journal Pre-proof such as tremolite and richterite in the high-Al amphiboles. The activities of these end member components in the Al-rich amphiboles are extremely small, and problems relating to site allocation of elements are likely to induce uncertainties in estimating temperature. In any case, the higher set of temperature values in the amphibolites appear erroneous because at these conditions, the metamorphosed arenites and argillaceous rocks within the supracrustal units are expected to experience melting, and white mica and chlorite are unlikely to be stable. These features are lacking in the supracrustal unit. The low-T, high-P metamorphic conditions obtained from the schists (Fig. 8a) are different from the low-P conditions retrieved from the amphibolites (Fig. 8b). The P-T conditions obtained for the amphibolites using the T a thermometers may correspond with post-peak conditions retrieved from the schists. Also, several researchers suggest that in contractional orogens, metamorphic P-T paths are seldom identical; instead, the P-T paths are diverse because individual crustal domains or tectonic slices within the orogen evolve along distinctive metamorphic P-T paths [START_REF] Selverstone | Metamorphic P-T paths from pelitic schists and greenstones in the southwest Tauern Window, Eastern Alps[END_REF] and references therein).

Anatectic basement gneisses

P-T estimates for the basement gneisses were obtained based on several thermometers and barometers applicable to the garnet-cordierite-plagioclase-sillimanite-biotite-quartz bearing mineral assemblage in samples AW 142A (Fig. 8c) and AW 372 (Fig. 8d). The P-T values in the two rocks were obtained from the two thermometers, e.g., garnet-cordierite [START_REF] Thompson | Mineral reactions in pelitic rocks; I, Prediction of PTX (Fe-Mg) phase relations[END_REF][START_REF] Holdaway | Fe-Mg cordierite stability in high-grade pelitic rocks based on experimental, theoretical, and natural observations[END_REF][START_REF] Bhattacharya | Fe-Mg mixing in cordierite; constraints from natural data and implications for cordierite-garnet geothermometry in granulites[END_REF][START_REF] Perchuk | Precambrian granulites of the Aldan shield, eastern Siberia, USSR[END_REF][START_REF] Wells | Chemical and thermal evolution of Archaean sialic crust, southern West Greenland[END_REF] and garnet-biotite (authors mentioned above). Pressures were estimated from the garnetaluminosilicate-silica-plagioclase (GASP; [START_REF] Newton | Thermodynamics of the garnet-plagioclase-Al 2 SiO 5-quartz geobarometer[END_REF][START_REF] Hodges | Geothermometry, geobarometry and the Al2SiO5 triple point at Mt Moosilauke, New Hampshire[END_REF] J o u r n a l P r e -p r o o f

Journal Pre-proof [START_REF] Ganguly | Mixing properties of aluminosilicate garnets: constraints from natural and experimental data, and applications to geothermo-barometry[END_REF][START_REF] Hodges | Error estimation and empirical geothermobarometry for pelitic systems[END_REF][START_REF] Koziol | Recalibration of the garnet-plagioclase-Al2SiO5-quartz (GASP) geobarometer and applications to natural processes[END_REF][START_REF] Koziol | Redetermination of the anorthite breakdown reaction and improvement of the plagioclase-garnet-Al2SiO5-quartz geobarometer[END_REF]) and garnet-cordierite-sillimanite-quartz (GCSQ; [START_REF] Thompson | Mineral reactions in pelitic rocks; I, Prediction of PTX (Fe-Mg) phase relations[END_REF][START_REF] Perchuk | Precambrian granulites of the Aldan shield, eastern Siberia, USSR[END_REF][START_REF] Holdaway | Fe-Mg cordierite stability in high-grade pelitic rocks based on experimental, theoretical, and natural observations[END_REF][START_REF] Wells | Thermal evolution of metamorphic rocks in the Central Highlands of Scotland[END_REF][START_REF] Wells | Chemical and thermal evolution of Archaean sialic crust, southern West Greenland[END_REF] barometers. The P-T estimates were obtained using compositions of (a) garnet (core) and biotite (inclusion) and (b) garnet (rim) and nearest neighbour biotite/cordierite in the matrix. For the GASP barometer, the compositions of matrix plagioclase were adopted. The pairs of garnet (core) and biotite (inclusion) yielded higher temperatures (>670 °C), whereas the garnet (rim) and matrix biotite/cordierite nearest-neighbour pairs (not in grain contact) furnished lower temperatures, typically <670 °C. The pressure estimates obtained from each of the two barometers did not vary outside the errors associated with the barometric formulations, i.e., ± 1 kbar. The maximum P-T conditions obtained from the intersections of the thermo-barometers ranged between 4.5-6.2 kbar, 625-725 °C (mean value 5.4 ± 0.8 kbar, 675 ± 50 °C) for AW 142A, and 4.0-6.5 kbar, 600-750 °C (mean value 5.2 ± 1.2 kbar, 675 ± 80 °C) for AW 372. The HT-LP conditions obtained for the 1.7-1.6 Ga pre-D2 high-grade metamorphism in the anatectic gneisses are compared with the 1.03-0.93 Ga D2-D3 metamorphism in the mica schists and amphibolites (for T a values) in the supracrustal unit in Fig. 8e.

P-T path reconstruction

P-T paths are reconstructed for the mica schist sample AW 44 (Fig. 9) and two anatectic gneisses, AW 142A and AW 372 (Fig. 10, 11). The bulk rock compositions were obtained by splintering, repeated coning and quartering and pulverising 4-5 kg of the rocks. For reconstructing the P-T paths, the three samples are selected because the rocks do not contain multi-component solid solution (such as hornblende) to avoid problems in reconstructing J o u r n a l P r e -p r o o f

Journal Pre-proof topologies of phase fields arising from uncertainties in complex a-X relationships. Also we selected the mineral assemblages in which Fe-Ti oxide phases either occur in accessory amount <1 vol% of whole rock (as in the mica-chlorite schist AW 44; Supplementary Material 3 ) or are lacking as in the anatectic gneisses AW 142A and AW 372 (Fig. 2a,b). In addition, ilmenite in the sample AW 44 is a solid solution between ilmenite (FeTiO 3 ) and pyrophanite (MnTiO 3 ) in the molar ratio 0.92 and 0.08 respectively (Table 3), and with negligible amounts of geikielite (MgTiO 3 ) and haematite (Fe 2 O 3 ). The sample (AW 44) with low abundance of Fe-Ti oxide with low Fe 2 O 3 content is to ensure the f(O2) conditions need not be retrieved for P-T path reconstruction. This is especially crucial for AW 44 because the mineral assemblage does not permit robust thermo-barometric formulations to be applied, and therefore f(O 2 ) cannot be determined in the absence of P-T estimates. In the other mica schist samples, either magnetite and/or ilmenite are present in somewhat higher proportion, and ilmenite contains higher mole fractions of Fe 2 O 3 in solid solution with ilmenite.

The P-T pseudosections were constructed using the Perple_X software of Connolly (2005; http://www.perplex.ethz.ch/) version 6.9.0 along with the database hp62ver.dat and solution_model_690.dat files. A uniform set of a-X relations was used for the solid solution minerals for the samples. However, for white mica, two different solution models were used to account for the diverse compositions of white mica in the mica schist (AW 44) and the anatectic gneisses (AW 142A, 372). The P-T paths were obtained for the bulk rock compositions based on the phase topology relations, and by comparing, as closely as possible, the theoretical and the measured compositions of minerals, and direction of change in the volume% of critical minerals.

Mica schist (AW 44)

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In constructing the NCKFMASHTi P-T pseudosection, the following minerals (in parenthesis)

and independent phase components [in square brackets] were adopted: Garnet (Gt [START_REF] Holland | Calculation of phase relations involving haplogranitic melts using an internally consistent thermodynamic dataset[END_REF] for garnet, phengite, chlorite, staurolite, orthopyroxene and chloritoid. The solution models for K-feldspar and plagioclase are adopted from [START_REF] Waldbaum | Mixing properties of sanidine crystalline solutions: II. Calculations based on volume data[END_REF] and Newton et al. (1981), respectively. In the computation, the model proposed by [START_REF] White | Progress relating to calculation of partial melting equilibria for metapelites[END_REF] for biotite was considered. For talc and carpholite, the a-X models listed in the solution_model_690.dat files were adopted.

The bulk rock composition for which the NCKFMASHTi pseudosection (Fig. 9a 3). For the mineral assemblage in AW 44, the P-T window was narrowed down to 5-15 kbar, 410-550°C (Fig. 9b). This P-T window (Fig. 11b) is contoured for Si (apfu) in phengite, the Ab content in plagioclase and X Mg Chl (=Mg/Mg+Fe). At the D1-D2

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Journal Pre-proof peak-P, T conditions (Fig. 9b), the relevant phase field comprising white mica, chlorite, clinozoisite, sphene, plagioclase and rutile is limited at higher pressure by lawsonite, glaucophane and chloritoid bearing assemblage, and garnet bearing assemblages occur at the high-T side. In the mica schists, lawsonite, glaucophane and chloritoid are lacking, and garnet is rare. At the peak P-T conditions of 10-12 kbar and 450-550 °C, consistent with the peak P-T estimates (Fig. 8), the computed chemical compositions of the minerals are: Si in phengite [3.24 apfu to 3.20 apfu], X Mg Chl [0.48-0.52], and X Ab in plagioclase lies in the range 0.84-0.80. The pseudosection reconstruction (Fig. 11b) shows rutile to be stable in the relevant phase field; the theoretically determined volume % of rutile is ≤ 0.08 for the peak assemblage. Also, rutile is lacking in any of the mica schists, and the stable Ti-bearing phase in AW 44 is ilmenite, present in < 1 vol% of the rock (Supplementary Material 3 ). A P-T pseudosection was also constructed for the same bulk composition (Fig. 9c) in the NCKFMASH system. The phase topologies and the isopleths change marginally with respect to those in the Ti-bearing system (Fig. 9b).

Apparently the inclusion of TiO 2 as a system component effectively stabilised low vol% of rutile and/or ilmenite, resulting in insignificant changes in the phase topologies and the compositional isopleths. The minor disparities between the theoretical and the measured compositional parameters possibly stem from the small errors in the bulk rock estimation and/or the standard state thermodynamic data as well as a-X relations in the multi-component solid solution phases adopted in the computations. We also extended the NCKFMASHTi system to include Mn. But as garnet stability expands due to the preferential partitioning Mn relative to the associated minerals [START_REF] White | The effect of Mn on mineral stability in metapelites revisited: New a-x relations for manganese-bearing minerals[END_REF], garnet appears as a stable phase in almost all phase assemblages in the P-T of interest for AW 44. This is inconsistent with the rarity of garnet in the mica schists, and hence the Mn-NCKFMASHTi system is not considered.

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The retrograde path in AW 44 is difficult to constrain due to the lack of adequate post-D2 mineral assemblages. However the Si-poorer D3 phengite (Table 3; Fig. 5g) interleaved with chlorite and clinozoisite are stable at lower pressure (Fig. 9b), and clearly such assemblages are indicative of decompression following the attainment of the peak-P conditions. The overall P-T path is deemed to be clockwise with decompression ± cooling in the retrograde sector (Fig. 9b).

A decompression ± cooling path in the retrograde sector of the clockwise P-T path (Fig. 9b) also explains the sporadic occurrence of post-D3 biotite in the mica schists (Tables 1,2), although biotite is lacking in AW 44. However, a counter-clockwise P-T path is inconsistent with the structural setting of the supracrustal unit, and also the path does not explain the absence of biotite interleaved with chlorite, phengite-rich mica, chlorite and quartz in the D1-D2 fabrics in any of the mica schists examined, including AW44. This is because biotite in equilibrium with chlorite and lower-Si mica is stable at lower pressure relative to the higher-P biotite-free celadonite richer mica bearing assemblages (Fig. 9b).

Basement anatectic gneisses (AW 142A, AW 372)

Since the gneisses are mineralogically heterogeneous with leucocratic layers comprising 35-40 vol% of the bulk rock (Fig. 3b,d), care was taken to splinter the rock into large blocks so that the leucosome:melanosome proportion was maintained as closely as possible. About 4 kg of the samples were used for obtaining bulk rock compositions. The details in methodology for determining the chemical compositions of the rock powders are provided in the Appendix. The , fa8L, zr8L, abL, sil8L, anL, kspL, wi8L, q8L, h2oL].

Quartz is taken to be in excess. The solution models used are those of [START_REF] Holland | Calculation of phase relations involving haplogranitic melts using an internally consistent thermodynamic dataset[END_REF] for garnet, staurolite, orthopyroxene, clinopyroxene, olivine and melt, [START_REF] White | The effect of Mn on mineral stability in metapelites revisited: New a-x relations for manganese-bearing minerals[END_REF] for cordierite, [START_REF] White | Progress relating to calculation of partial melting equilibria for metapelites[END_REF] for biotite, [START_REF] Waldbaum | Mixing properties of sanidine crystalline solutions: II. Calculations based on volume data[END_REF] for K-feldspar, Newton et al. (1981) for plagioclase, [START_REF] Coggon | Mixing properties of phengitic micas and revised garnet-phengite thermobarometers[END_REF] and [START_REF] Auzanneau | Titanium in phengite: a geobarometer for high temperature eclogites[END_REF] for muscovite.

In the P-T pseudosection reconstructions, the fluid was assumed to be pure H 2 O, and the amount of H 2 O was constrained by the LOI values in the two gneisses. The LOI value primarily corresponds to the amount of H 2 O structurally held in the hydrous minerals (biotite) in the gneisses. The LOI values are expected to be lower than the amount of H 2 O initially present in the rocks (pre to syn-D1a) for two reasons. First, the leucosomes occur as continuous layers, and this demonstrates that undefined amounts of melt were able to segregate, and migrate along interconnected D1a porosity networks [START_REF] Holness | Melt segregation from silicic crystal mushes: a critical appraisal of possible mechanisms and their microstructural record[END_REF]. It is possible therefore that a fraction of the melt may have escaped during and prior to the D1a deformation. Also, melt escape would

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Journal Pre-proof render the chemical composition of the rock more restitic relative to the protolith. Second, H 2 O is strongly partitioned into the melt phase during melting, and therefore the H 2 O dissolved in the melt is likely to have escaped as well. Thus the P-T pseudosection reconstructed using the analyzed bulk rock composition, and the LOI value, are likely to reflect the effects of post-D1a sub-solidus metamorphic modifications experienced by the melt-extracted restitic gneisses. It follows that the supra-solidus pre/syn-D1a P-T history can be qualitatively proposed.

The Mn-NCKFMASHTi and the Mn-NCKFMASH P-T pseudosections for AW 142A (Fig. 10a,b) and AW 372 (Fig. 11a,b) are shown in the P-T window (4.6-7 kbar, 660-820°C)

for the mineral assemblages of interest involving quartz, biotite, plagioclase, garnet, cordierite, sillimanite, alkali feldspar and melt (Figs. 10a,b,11a,b). The phase topologies for the Mn-NCKFMASHTi and the Mn-NCKFMASH P-T pseudosections for each of the two rocks are similar, except that ilmenite appears in less than 1 vol% in the Ti-bearing system for AW 142 and AW 372, both of which lack Fe-Ti oxide phases. Therefore we have retrieved the possible P-T paths from the compositional contours for X Fe , X Mn and X Ca in garnet (Fig. 7), the compositions of biotite, cordierite, plagioclase (Supplementary Material 4-5 ) and relative changes in the volume, rather than the absolute modal values, of the minerals (garnet, cordierite and melt) based on reaction textures. These textures relate to (a) the growth of garnet due to incongruent melting reactions at the expense of biotite, sillimanite, cordierite and feldspar, and (b) the increase in the vol% of cordierite via sub-solidus reactions that consume biotite, garnet and sillimanite (Fig. 2a,b).

The garnet core composition in our samples (Fig. 7a) matches well with the theoretical isopleths of X Fe Grt , X Mn Grt , X Ca Grt and X Mg Grt values (Fig. 10a) obtained from the Mn-NCKFMASH P-T pseudosection (Fig. 10b); however the rim compositions of garnets (X Fe

Grt

J o u r n a l P r e -p r o o f

Journal Pre-proof :0.77, X Mg Grt :10 for AW 142A and X Fe Grt :0.75, X Mg Grt :12 for AW 372) in our samples deviate from the X Fe Grt and X Mg Grt compositional contours within the P-T window (Figs. 10b,11b). The qualitative prograde segment of the P-T path has been inferred to extend from a garnet-free field leading up to the core composition of the garnet (Alm73-74Prp17Grs5Sps5) in sample AW 142. For AW 372, since there is no Grt free field, the prograde segment has been constructed in the direction of increasing modal abundance of Grt and melt and decreasing modal abundance of Crd leading up to the core Grt composition of Alm71-72Prp16Grs4Sps8-9. This is done to account for the pre-to syn-D1a anatexis that produced garnet at the expense of biotite-sillimanite-cordierite inclusions hosted in the garnets (Fig. 2a,b).

The retrograde segment of the P-T path for both AW 142 and AW 372 has been constructed starting from the garnet core composition (Alm73-74Prp17Grs5Sps5 in AW 142, and Alm71-72Prp16Grs4Sps8-9 in AW 372) in the overall direction of increase in the X Fe Grt and X Mn Grt contents, increase in the modal abundance of Crd and decrease in modal abundance of Grt. This path accounts for the decrease in volume of garnet due to post-D1b decomposition to double layered biotite-plagioclase aggregates (in AW 142), and the stabilisation of cordierite mantles around garnet via the model FAS reaction, 2Fe3Al2Si3O12 (in Grt) + 4Al2SiO5 (Sill) + 5SiO2 (Qtz) → 3Fe2Al4Si5O18 (in Crd) in AW 372. The P-T path so obtained describes a U-shaped clockwise pattern in both samples (Fig. 10b,11b). The reconstructed clockwise P-T path, with the peak P-T anatectic conditions during D1a at 5 kbar, 720 °C is followed by a retrograde sector involving decompression (Fig. 10b,11b). The clockwise geometry in the anatectic gneisses is similar to the P-T paths retrieved in the basement gneisses in the Chottanagpur Gneiss Complex and the southern and central domains of Satpura Mobile Belt (summarised in [START_REF] Banerjee | Tectonics of the Greater India Proterozoic Fold Belt, with emphasis on the nature of curvature of the belt in west-central India[END_REF] eastwards within the CITZ vis-à-vis the southern arm of the GIPFOB (Fig. 1).

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DISCUSSION

Time of accretion

The significant findings in this study have been the documentation of LT-HP metamorphic conditions along a clockwise P-T path in the supracrustal rocks using multiple mineral thermobarometric formulations and NCKFMASH P-T pseudosection analyses in quartz-chlorite-whitemica-biotite-albite-clinozoisite ± garnet assemblages. The clockwise LT-HP metamorphism retrieved from AW 44 (Fig. 9) is unique because the metamorphic path is synkinematic with topto-the-south D 2 thrusting associated with convergence between two regional orogens, e.g. the N/NNE-striking Aravalli-Delhi Fold Belt (ADFB) in the north that terminates against the western end of the E-W striking Central Indian Tectonic Zone (CITZ). The timing of the P-T path in the GC sector may be constrained within reasonable limits. The supracrustal rocks affected by the top-to-the-south thrusting and LT-HP metamorphism was intruded by the 0.95-0.93 Ga blastoporphyritic syn-D3 granitoids (Banerjee et el., 2022a, b) and post-dated the emplacement of the ~1.03 Ga granitoids (Banerjee et el., 2021a). In addition, the dates retrieved from the idioblastic metamorphic monazites in a mica schist (Banerjee et al., 2022a) range between 1.05-0.92 Ga (Banerjee et al., 2022a). We argue, therefore, that the syn-thrusting clockwise LT-HP metamorphism in the supracrustal rocks (Fig. 9b) occurred in the Early Neoproterozoic, 1.03-0.95 Ga U-Pb dates (Banerjee et al., 2022a, accompanying article).

Lack of pervasive LT-HP metamorphism in the basement gneisses

The clockwise P-T path at HT-LP granulite facies conditions (Figs. 10,11) retrieved for the anatectic gneisses is among the first to be documented in the Godhra-Chhota Udepur sector. The

J o u r n a l P r e -p r o o f

Journal Pre-proof path is similar to those retrieved for similar rocks in the CGC and the SMB crustal domains in the CITZ (summarised in [START_REF] Banerjee | Tectonics of the Greater India Proterozoic Fold Belt, with emphasis on the nature of curvature of the belt in west-central India[END_REF]. LA-ICP-MS U-Pb (Zircon) dating by [START_REF] Banerjee | Early Neoproterozoic tectonics in the Godhra -Chhota Udepur sector: Evidence for two-stage accretion in the Greater India Proterozoic Fold Belt (GIPFOB)[END_REF] and in the accompanying article (Banerjee et al., 2022a) demonstrates that this high-grade metamorphism in the anatectic gneisses occurred during the Late Paleoproterozoic

(1.7-1.6 Ga). This P-T path is distinct from the Early Neoproterozoic clockwise P-T path with low-T, high-P peak metamorphic conditions recorded in the supracrustal rocks (Fig. 8e). But the P-T paths in the anatectic gneisses do not record the overprinting effects of the younger Early Neoproterozoic LT-HP path in the closely associated supracrustal rocks (Fig. 9b) in the tectonic mélange. However, sporadic occurrences of randomly oriented fibrolites of chlorite, phengitic micas and rare paragonite replacing biotite-cordierite-plagioclase assemblages (Fig. 2e) indicate that the basement gneisses experienced the D2-D3 low-T metamorphic effects, but compelling evidence for the overprinting effects of the low-T metamorphism induced by the Early Neoproterozoic crustal thickening in the anatectic basement gneisses is lacking.

The HT-LP metamorphism in the ~1.65 Ga basement gneisses predates the Early Neoproterozoic LT-HP metamorphic event by at least 600 million years, and therefore, the basement anatectic gneisses are likely to have cooled sufficiently prior to being remetamorphosed at the lower temperature. This implies that the decompression paths in the ~1.65

Ga gneisses and the 1.03-0.93 Ga supracrustal rocks were not time equivalent, and instead the decompression paths are two distinct metamorphic events separated by ~600 million years. It also stands to reason that LT-HP metamorphic over-printing in the gneisses would require the stabilization of hydrous minerals at the expense of high-T anhydrous minerals. -Dry‖ high-grade rocks in the middle to lower crust are mechanically strong [START_REF] Jackson | Metastability, material strength, and the support of mountain belts[END_REF], and cratons can sustain large stresses in continental collision zones (Yang et al., 2020). In such cratonic rocks,

J o u r n a l P r e -p r o o f

Journal Pre-proof the stabilization of low-T hydrous minerals is likely to be facilitated if crustal weakening is induced by fluid infusion [START_REF] Jamtveit | [END_REF] and/or grain size reduction (Yang et al., 2020) as in zones of high shear strain. [START_REF] Jamtveit | [END_REF]

J o u r n a l P r e -p r o o f

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The profusion of post-D2, syn-D3 Early Neoproterozoic syn-collisional S-type granitoids (Banerjee et al., 2022a, b) emplaced in the thickened accretion zone in excess of ~40 km needs to be explained. Additionally, some of the granitoids were deformed (D3) when hot, although the deformation outlasted granitoid emplacement. These features have also been noted in the Chottanagpur Gneiss Complex [START_REF] Sequeira | The anatomy and origin of a syn-convergent Grenvillian-age metamorphic core complex, Chottanagpur Gneiss Complex, Eastern India[END_REF][START_REF] Sequeira | The ~1.4 Ga A-type granitoids in the -Chottanagpur crustal block‖ (India), and its relocation from Columbia to Rodinia[END_REF] far to the east (Fig. 1a) of the present study area, within the CITZ. Clearly, there needs to be a mechanism that would initiate melting in the basement gneisses and induce ascent of voluminous granitoids in the absence of demonstrable crustal extension. We ascribe the features to a subduction polarity reversal [START_REF] Willett | Subduction of Asian lithospheric mantle beneath Tibet inferredfrom models of continental collision[END_REF][START_REF] Wang | A neoarchean subduction polarity reversal event in the North China Craton[END_REF]. In this process, the crustal thickening occurred during the initial phase of northward subduction of the CITZ below the ADFB lithologies in the north (Fig. 12). We suggest this led to the interleaving of the CITZ gneisses dominant in the south with the Archean basement rocks equivalent to BGC-I in the ADFB to the north (accompanying article; Banerjee et al., 2022a).

In the next step, the expansive emplacement of 0.95-0.93 Ga S-type granitoids (Banerjee et al., 2022a) in the thickened crust in a down-going plate needs to be explained. The emplacement of these granitoids would require elevated temperatures at the source region of the granitoids. We suggest, following [START_REF] Willett | Subduction of Asian lithospheric mantle beneath Tibet inferredfrom models of continental collision[END_REF], that the delamination of the down-going CITZ slab during continued crustal convergence led to the initiation of melting. But slab delamination broadly contemporaneous with crustal shortening would necessitate a reversal in the subduction polarity, i.e. the over-ridden CITZ plate evolved into an over-riding plate. Slabdelamination and south-directed subduction in its wake caused top-to-the-south thrusting of the supracrustal rocks and parts of the ADFB domain, and asthenospheric upwelling triggered melting of the tectonically interleaved CITZ and the ADFB lithologies (Fig. 12). The crustally-

J o u r n a l P r e -p r o o f

Journal Pre-proof derived melts ascended along a network of orogen-parallel post-D2 to syn-D3 channels (D3 transpressional shear zones) through a feed-back relationship between melt localisation and strain partitioning in a rheologically heterogeneous partially molten crust experiencing shortening [START_REF] Brown | The mechanism of ascent and emplacement of granite magma during transpression: A syntectonic granite paradigm[END_REF]Bhadra et al., 2007;[START_REF] Jamieson | Synconvergent ductile flow in variable strength continental crust: Numerical models with application to the western Grenville orogen: Tectonics[END_REF]. Experimental studies and theoretical considerations [START_REF] Vigneresse | Rheological transitions during partial melting and crystallization with application to felsic magma segregation and transfer[END_REF] suggest that difference in the dynamic viscosity in a partially molten crust is likely to vary in excess of several orders of magnitude. Strain-induced by crustal shortening would be preferentially partitioned within the magma-bearing zones (cf. Vigneresse and Tikoff, 1999) and assist in magma ascent and nucleation of the D3 shear zones. This would explain the flow-textured granitoids deformed at supra-solidus conditions (Banerjee et al. 2022a, b); the crustal shortening event outlasted granitoid emplacement, and the deformation continued at sub-solidus state in the D3 granitoids, the supracrustal rocks and the basement gneisses.

CONCLUDING REMARKS

The results of this study integrated with those of [START_REF] Banerjee | Tectonics of the Greater India Proterozoic Fold Belt, with emphasis on the nature of curvature of the belt in west-central India[END_REF]Banerjee et al. ( , 2022a, b, b) provide a regional tectonic framework for CITZ-ADFB accretion based on a large body of new structural, chronological, geochemical and metamorphic data that did not exist before from the crucial Godhra-Chhota Udepur sector. The tectonic restoration model proposed here is based on the findings in the Precambrian rocks exposed in the Godhra-Chhota Udepur sector. However, the veracity of the proposed model needs to be corroborated from an analysis of superposed deformations and kinematics of mesoscale structures, robust geochronology and quantitative metamorphic phase equilibrium analyses of critical rocks in the Lunavada Group of the ADFB J o u r n a l P r e -p r o o f high-P terrains [START_REF] Velde | Si+ 4 content of natural phengites[END_REF][START_REF] Kurata | Low-grade progressive metamorphism of pelitic schists of the Sazare area, Sanbagawa metamorphic terrain in central Sikoku, Japan[END_REF][START_REF] Coombs | Pumpellyite-actinolite facies schists of the Taveyanne Formation near Loèche, Valais, Switzerland[END_REF][START_REF] Dempster | Zoning and recrystallization of phengitic micas: implications for metamorphic equilibration[END_REF][START_REF] Chopin | Coesite and pure pyrope in high-grade blueschists of the Western Alps: a first record and some consequences[END_REF][START_REF] Banno | Chromian sodic pyroxene, phengite and allanite from the Sanbagawa blueschists in the eastern Kii Peninsula, central Japan[END_REF]Itaya and Fukui, 1993;[START_REF] Carswell | Metamorphic evolution, mineral chemistry and thermobarometry of schists and orthogneisses hosting ultra-high pressure eclogites in the Dabieshan of central China[END_REF][START_REF] Miyashita | K-Ar age and chemistry of phengite from the Sanbagawa schists in the Kanto Mountains, central Japan, and their implication for exhumation tectonics[END_REF][START_REF] Ishwar-Kumar | A Rodinian suture in western India: New insights on India-Madagascar correlations[END_REF][START_REF] Park | Mg-Phengite in Carbonate Rock Syngenetically Formed from Hydrothermal Fluid: Micro-Textural Evidence and Mineral Chemistry[END_REF][START_REF] Ren | Grenvillian and early Paleozoic polyphase metamorphism recorded by eclogite and host garnet mica schist in the North Qaidam J o u r n a l P r e -p r o o f Journal Pre-proof orogenic belt[END_REF].

Figure captions

(f) BSE image and X-ray element maps of Al. Si, Fe and K in mica schist AW 46B.

Arrow heads show the location of white micas. the observations made in this study and those in the accompanying article (Banerjee et al., 2022a) at the Godhra-Chhota Udepur sector.

Table caption

Table 1: Electron probe micro analytical data and structural formula of selected white mica (and quartz for reference only) in mica schists (AW 46B, AW 82A and AW 91). 6. 9 7 6. 9 4 6. 9 5 6. 9 6 6. 9 3 6. 9 4 6. 9 6 6. 9 4 6. 9 6 6. 9 0 6. 9 2 6. 9 8

  g. Si = 3.04-3.07 apfu, Ti = <0.02 apfu, X Fe [= Fe 2+ /(Fe 2+ + Mg)] = 0.44-0.52, X K [=K/(K+Na)] =0.85-0.90 in AW 142A (based on 14 spot analysis; and Si = 3.02-3.09 apfu, Ti = <0.02 apfu,J o u r n a l P r e -p r o o fJournal Pre-proof X Fe [= Fe 2+ /(Fe 2+ + Mg)] = 0.44-0.52, X K [=K/(K+Na)] =0.89-0.94 in AW 372 (based on 8 spot analysis). On the other hand, 4 spot analyses on paragonite yielded, Si = 3.05-3.11 apfu, Ti = <0.01 apfu, X Fe [= Fe 2+ /(Fe 2+ + Mg)] = 0.45-0.79, X K [=K/(K+Na)] =0.09-0.16. Clearly, the white micas in the two samples are phengitic, and by implication the high-grade anatectic gneisses experienced the collateral effects of low-T, high-P metamorphism that characterise the supracrustal rocks.

Fig. 1 .

 1 Analytical details of the whole rock analysis are presented in Appendix B. J o u r n a l P r e -p r o o f

  ) was constructed in the P-T window, 2-20 kbar and 450-650°C is composed of (in wt%) SiO 2 = 57.81, TiO 2 = 0.83, Al 2 O 3 = 19.24, FeO = 6.95, MnO = 0.10, MgO = 3.96, CaO = 0.50, K 2 O = 4.75, Na 2 O = 0.75, H 2 O (loss on ignition, LOI) = 5.40 (Total = 99.79 wt%). The quoted LOI value is computed after drying out absorbed H 2 O. The representative ranges of compositions of minerals in AW 44 (Table 3) are the following: D2 muscovite [Si = 3.24-3.26 apfu], D3 muscovite [Si = 3.14-3.19 apfu]; muscovite [Fe = 0.11-0.15 apfu], chlorite [Mg/(Mg + Fe) = 0.42-0.44]; plagioclase [Ab = 0.85 mol%]; clinozoisite (Al/3 = 0.90], and ilmenite [ilmenite: pyrophanite = 0.92:0.08] (Table

  major element compositions (in wt %) for the rocks are as follows: AW 142A [SiO 2 = 61.64, TiO 2 = 0.75, Al 2 O 3 = 16.20, FeO = 9.90, MnO= 0,03, MgO = 3.96, CaO = 0.95, K 2 O = 4.16, Na 2 O = 0.82, H 2 O (LOI) = 2.30 (Total = 100.71 wt%)]; and AW 372 [SiO 2 = 61.52 TiO 2 = 0.60, J o u r n a l P r e -p r o o f Journal Pre-proof Al 2 O 3 = 16.52, FeO 10.00, MnO= 0,39, MgO = 2.69, CaO = 2.33, K 2 O = 3.10, Na 2 O = 1.72, H 2 O(loss on ignition, LOI) = 1.73 (Total = 100.60 wt%)]. For the P-T pseudosection reconstructions, the compositions of AW 142A (Fig.2a, 3b, d) and AW 372 (Fig.2b) were approximated to the Mn-NCKFMASHTi and Mn-NCKFMASH systems. In the reconstruction of the pseudosections, the following minerals (in parenthesis) and independent phase components [in square brackets] were considered: Garnet (Gt) [

  demonstrate that the Caledonian eclogites formed at the expense of the Proterozoic granulites in the Bergen Arc (western Norway) due to pressure perturbations and fluid-induced weakening of the stressed lower crust; the authors conclude that the eclogitization was not the result of burial metamorphism alone. Following their argument, we suggest that the lack of D2 axial planar fabric in the gneisses and the absence of fabric-defining low-T hydrous minerals (vis-à-vis paucity of fluids) are likely to have contributed to the unresponsive nature of the high-grade rocks to the Early Neoproterozoic low-T metamorphic event in the older gneisses. Another factor that may have contributed to the passivity of the basement gneisses to the Early Neoproterozoic hydration event is the preferential partitioning of D2 strain in the rheologically weak supracrustal rocks (dominated by weak to shear mica schists and meta-carbonate rocks) interleaved with the mechanically strong older high-grade gneisses. Grain size reduction and enhanced fluid mobility are expected to be high in the gneisses in and adjoining the gneiss-supracrustal rock contacts and the gneisses; such structurally weak locales are likely to best exhibit retrograde overprinting. It is possible that such high-D2 strain locales within the anatectic gneisses, if preserved, could not be identified during the course of this study. Hence, stronger imprints of stabilization of low-T hydrous minerals in the gneisses remain undocumented.1.3 Dynamics of accretionFor a comprehensive reconstruction of the dynamics of accretion between ADFB and CITZ, the inferences in this work are integrated with those in earlier studies (Banerjee et al.,J o u r n a l P r e -p r o o fJournal Pre-proof 2021, 2022b) and in the accompanying article(Banerjee et al., 2022a) in the Godhra-Chhota Udepur sector. The important evidences are: (a) The D2 (thrust-dominated) and D3 (wrenchdominated) deformations constitute a progression in NNE-SSW crustal shortening that resulted in orogen-parallel stretching(Banerjee et al., 2022a, b). (b) The top-to-the-south thrust dominated D2 deformation(Banerjee et al., 2022a, b) and crustal thickening (~1.0 Ga) recorded in the supracrustal rocks (this study) led to the juxtaposition of the 1.7-1.6 Ga high-grade anatectic basement gneisses of the CITZ with the ~2.5 Ga foliated granitoids similar in age to the Berach granite and its chronological equivalents in the ADFB (accompanying article;Banerjee et al., 2022a). (c) The lack of Late Paleoproterozoic high-grade metamorphism in the ~2.5 Ga ADFB foliated granites and the absence of Archean dates in the Late Paleoproterozoic CITZ gneisses suggests the two terranes (ADFB-CITZ) were tectonically accreted at ~1.0 Ga(Banerjee et al., 2022a, b). (d) The accretion was associated with the post-D2 to syn-D3 the emplacement of extensive S-type granitoids at 0.95-0.93 Ga(Banerjee et al., 2022a, b). (e) The syn-D3 trains and imbrications among euhedral K-feldspar phenocrysts and the common occurrence of chessboard sub-grain microstructure in quartz grains(Banerjee et al., 2022a, b;[START_REF] Mamtani | Granite emplacement and its relation with regional deformation in the Aravalli Mountain Belt (India)-inferences from magnetic fabric[END_REF] suggest that the deformation in the granitoids occurred at high-T and persisted during and outlasted the emplacement of the granitoids. (f) The granitoid emplacements culminated with the nucleation of basement piercing E-striking steep-dipping D3 transpressional shear zones(Banerjee et al., 2022a, b). (g) No evidence of post-D2 extension-related structural features were observed during investigation in and around 450 field stations we visited in the GC sector. (h) ~0.95 Ga granitoids are not as yet reported within the Lunavada Group of low-grade metamorphic rocks north of the GC sector.

Fig. 1 :

 1 Fig. 1: (a) Structural-lithological map of the Godhra-Chhota Udepur sector. Localities discussed

Fig. 2 :Fig. 3 :

 23 Fig. 2: Back-scattered electron (BSE) images of melanocratic gneisses; (a) leucosome-

Fig. 5 :

 5 Fig. 5: (a, b) Photomicrographs of mica schist (AW 46B) showing (a) inter-relationship between

Fig. 6 :

 6 Fig. 6: (a) Photomicrograph of the xenoblastic garnet porphyroblast in relation to D2 and D3

Fig. 7 :Fig. 8 :

 78 Fig. 7: Chemical variations in garnet porphyroblasts in anatectic gneisses AW 142A, 372. X-ray

Fig. 9 :

 9 Fig. 9: P-T path reconstruction in white mica-chlorite schist AW 44 (mineral chemical data in

Fig. 10 :

 10 Fig. 10: (a) Mn-NCKFMASHTi and (b) Mn-NCKFMASH P-T pseudosection reconstructions in

Fig. 11 :

 11 Fig. 11: (a) Mn-NCKFMASHTi and (b) Mn-NCKFMASH P-T pseudosection reconstructions in

☒

  Figure1

Figure 4

 4 Figure4

Figure 5

 5 Figure5

Figure 6

 6 Figure6

Figure 7

 7 Figure 7

Figure 8

 8 Figure8

Figure 9 Figure 10

 910 Figure9

Figure 11

 11 Figure11

Figure 12

 12 Figure12

  Journal Pre-proof layers are studded with round to elliptical aggregates of randomly-oriented serpentine grains. In rare instances, serpentine also occurs as trans-granular vermiform veins. We suggest these circular mono-mineralic serpentine grain aggregates to be pseudomorphs of former forsterite grains. The ferromagnesian minerals in sample AW 157B are highly Mg-rich, i.e. X Fe

		Bt
	[=Fe 2+ /(Fe 2+ +Mg)] varies in the range 0.05-0.06, and in clinopyroxene, X Fe	Cpx varies in the range
	is 0.04-0.08.

The carbonate-rich J o u r n a l P r e -p r o o f 3.2 Mica-chlorite schists

(AW 44, AW 46B, AW 91 and AW 82A)

The mica schists are dominated by quartz, chlorite and white mica, modally subordinate amount of clinozoisite, and accessory amounts of biotite, sphene and ilmenite. Garnet is a rare mineral observed locally in only one sample.

[START_REF] Das | A preliminary study of thermal metamorphism in the Champaner Group of rocks in Panchmahals and Vadodara districts of Gujarat[END_REF]

reported kyanite, andalusite and cordierite from several localities. The alumino-silicate polymorphs and cordierite are lacking in the mica schist samples examined from the supracrustal unit, but cordierite associated with garnet, sillimanite and biotite was observed in the melanocratic gneisses in several localities (see below).

Table 2

 2

	); chlorite in AW 44 is still less ferroan with

  3+ /(Fe 2+ + Fe 3+ ) varies in the range 0.01-0.05 and <0.01, respectively (Fe 3+ in amphiboles computed followingLeake et al.'s 1997 formulation). X Fe [=Fe 2+ /(Fe 2+ + Mg)] in chlorite are intermediate to the amphiboles, e.g. 0.46-0.50. In clinozoisite, Fe 3+ /(Al 3+ + Fe 3+ ) varies between 0.09 and

0.15. Plagioclase is albite in composition, with An mol% < 4.

  Alm 77 Prp 10 Grs 4 Sps 9 in AW 142A, and Alm 75 Prp 12 Grs 4 Sps 9

The interior of the garnet grains are chemically homogenous, i.e., Alm 73-74 Prp 17 Grs 5 Sps 5 in AW 142A, and Alm 71-72 Prp 16 Grs 4 Sps 8-9 in AW 372. Towards the garnet margin, garnet in both samples becomes progressively richer in X Fe and X Mn , poorer in X Mg , and X Ca remains nearly constant (Fig.

7

). At the margin, garnet compositions are

  )[alm, py, grs, sps], phengite (Pheng)[pa, cel, fcel, mu], chlorite (Chl)[mnchl, daph, ames, afchl, clin], biotite (Bio)[fbi, tbi1, ann, phl, east], plagioclase (Pl) [abh, an], K-feldspar (Kfs)[San], staurolite(St) [mst, fst, mnst], talc (T) [ta, fta, tats], orthopyroxene (Opx) [mgts, en, mots, feots, fs], chloritoid (Ctd) [mnctd, fctd, mctd], carpholite (Carp)[mcar, fcar]. SiO 2 and pure H 2 O were taken to be in excess. The solution models used are those of

Table 2 :

 2 Electron probe micro analytical data and structural formulae of biotite[11(O, OH, F, Cl)

	basis], chlorite [14(O) basis], clinozoisite [12.5(O) basis] and plagioclase [8(O) basis] for
	samples AW 46B and AW 91 and garnet [8 (O) basis] in AW 91.

Table 3 :

 3 Electron probe micro analytical data and structural formula of selected white mica (and quartz for reference only), chlorite plagioclase, clinozoisite and ilmenite in mica schist AW 44. Yang, J., Kaus, B. J. P., li, Y.,Leloup, P. H., Popov, A. A., Lu, G., Wang, K., Zhao, L., 2020.

										Journal Pre-proof
			Lower crustal rheology controls the development of large offset strike-slip faults during
			the		Himalayan-Tibetan	orogeny.	Geophysical	Research	Letters		47.
			https://doi.org/10.1029/2020GL089435
	Table 1: Electron probe micro-analytical data and structural formulae of phengitic micas [11(O,OH,F,Cl) basis ]
	and quartz [4(O) basis] from sample AW 46B, AW 91 and AW 82A AW 46B AW 91 P h P h P h P h P h P h Q z P h P h P h P h P h SiO2 46 .6 47 .5 47 .5 46 .9 47 .8 48 .8 99 .8 47 .9 48 .3 48 .0 48 .9 46 .5 TiO2 0. 44 0. 48 0. 44 0. 51 0. 47 0. 44 bd l 0. 40 0. 29 0. 23 0. 26 0. 20 Al2 O3 34 .7 33 .7 28 .7 32 .0 30 .4 30 .5 bd l 31 .0 32 .0 32 .6 32 .1 31 .3 Cr2 O3 0. 04 0. 06 0. 06 0. 03 bd l bd l bd l 0. 02 bd l 0. 04 bd l 0. 07 FeO 3. 07 3. 02 4. 23 4. 02 4. 90 4. 76 0. 02 3. 67 2. 97 CaO bd l bd l 0. 08 0. 11 0. 02 bd l 0. 02 0. 06 0. 01 0. 05 bd l 0. 03 Na2 O 1. 01 0. 68 0. 22 0. 45 0. 38 0. 50 bd l 0. 30 0. 42 0. 30 0. 24 0. 22 K2O 9. 88 10 .2 10 .0 8. 98 10 .2 10 .2 0. 01 10 .1 10 .7 10 .7 10 .9 10 .0 BaO 0. 36 0. 37 0. 26 0. 32 0. 33 0. 31 bd l 0. 22 0. 21 0. 20 0. 18 0. 15 ZnO bd l bd l 0. 05 bd l bd l bd l 0. 01 0. 05 bd l bd l bd l bd l J o u r n a l P r e -p r o o f P h Q z P h P h 47 .0 99 .3 46 .8 47 .2 0. 40 0. 02 0. 21 0. 24 30 .3 0. 19 33 .7 33 .8 0. 08 bd l --1. 52 0. 02 0. 92 0. 99 bd l 0. 08 bd l bd l 0. 39 bd l 0. 32 0. 33 10 .7 bd l 10 .7 10 .8 0. 21 bd l --bd l bd l --	AW 82A P h P h 47 P h .0 47 .6 47 .4 0. 15 0. 57 1. 51 33 .4 32 .5 31 .6 ---0. 97 1. 27 1. 33 bd l bd l bd l 0. 35 0. 35 0. 27 10 .6 10 .5 10 .4 ------	P h 46 .7 0. 23 34 .1 -0. 84 bd l 0. 34 10 .6 --	Qz 10 0.6 bdl 0.0 1 -0.0 1 0.0 1 bdl 0.0 3 --
	P2O 5	0. 01	bd l	bd l	bd l	bd l	bd l	0. 04	bd l	bd l	bd l	0. 02	bd l	bd l	bd l	0. 02	0. 01	bd l	bd l	0. 04	bd l	bdl
	Tot	96	96	93	94	96	97	99	95	96	96	97	92	92	99	95	96	95	96	95	96	10
	al		.7	.9	.4	.5	.2	.4	.9	.7	.5	.3	.3	.8	.8	.4	.5	.5	.4	.4	.2	.0	0.6
			3.	3.												0.	3.	3.	3.	3.	3.	3.	1.0
	Si		08	13												99	13	13	15	16	18	11	0
			0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.0
	Ti		02	02	02	03	02	02	00	02	01	01	01	01	02	00	01	01	01	03	08	01	0
			2.
	Al		71
	Cr		0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	-	-	-	-	-	-	-
	Fe	2+	0. 17	0. 17	0. 24	0. 23	0. 28	0. 26	0. 00	0. 21	0. 16	0. 14	0. 16	0. 16	0. 13	0. 01	0. 16	0. 17	0. 16	0. 20	0. 15	0. 17	0.0 0
	Mn	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	0. 00	-	-	-	-	-	-	-

Table 2 :

 2 Electron probe micro-analytical data and structural formulae of biotite [11(O, OH, F, Cl) basis], chlorite [14(O) basis], garnet [8 (O) basis], epidote [12.5(O) basis] and plagioclase [8(O) basis] for samples AW 46B and AW 91

	SiO2 TiO2 Al2O3 Cr2O3 Fe2O3 FeO MnO MgO	AW 46B Ep 37. 8 0.1 2 23. 1 0.0 5 12. 8 11. 5 0.4 0 0.0 1 J o u r n a l P r e -p r o o f AW 91 Chl Ch l Ep Pl Pl Grt core Grt rim Bt Bt 39.1 25.4 Bt 25. 8 37. 6 68.5 68.2 37.0 37.8 38.8 37.9 2.21 0.05 0.0 9 bdl 0.02 0.01 0.09 0.03 1.51 1.64 16.7 20.4 21. 1 23. 3 19.7 19.7 20.8 21.4 17.7 17.7 0.11 bdl 0.0 3 0.0 8 0.01 0.01 0.04 bdl bdl 0.08 ---13. 0 ------19.4 25.1 25. 1 11. 7 0.12 0.05 29.6 31.5 20.1 20.7 0.12 0.24 0.2 9 0.2 6 bdl bdl 5.34 3.17 0.12 0.16 9.76 14.0 14. 6 0.0 3 bdl bdl 1.49 1.77 8.61 8.63	Ch l 24. 9 0.0 6 20. 7 0.0 6 -28. 8 0.4 9 11. 3	Ch l 26. 7 0.0 6 20. 5 0.0 1 -27. 4 0.4 6 11. 7	Pl 68.0 67.1 Pl bdl bdl 20.0 20.4 bdl bdl --0.09 0.26 bdl bdl bdl 0.06
	CaO	0.64 0.06	0.0 2	23. 7	23. 3	0.16 0.29	5.55	5.59	0.38 0.28	0.0 2	0.2 1	0.71 0.33
	Na2O	0.17 0.02	0.0 3	0.0 1	bdl 12.5 12.4	0.06	0.03	0.09 0.09	0.0 1	0.0 1	12.2 11.7
	K2O	7.13 0.06	0.0 4	bdl bdl 0.06 0.09	bdl	0.03	7.94 8.20	0.0 3	0.4 7	0.10 0.46
	BaO	bdl	bdl	bdl bdl	0.0 4	0.03	bdl	0.01	bdl	bdl	bdl	bdl bdl	bdl	bdl
	ZnO	0.06 0.00	0.0 0	0.0 2	bdl	bdl	bdl	0.04	0.07	0.05 0.03 bdl	0.1 9	bdl	bdl
	P2O5	bdl	bdl	bdl bdl bdl 0.01	bdl	0.05	0.04	bdl	bdl	0.0 1	0.0 2	0.01	bdl
	Total	95.4 85.3	87. 0	96. 8	96. 3	101. 1	100. 8	100.0	101.5 95.4 95.4	86. 4	87. 7	101. 1	100. 2
	Si	2.91 2.75	2.7 3	3.0 1	3.0 1	2.97 2.97	2.99	3.00	2.91 2.87	2.7 2	2.8 5	2.95 2.94

Table 3

 3

			: Electron probe micro-analytical data and structural formulae of phengitic micas [11(O,OH,F,Cl) basis ],
	quartz [4(O) basis, chlorite [14(O) basis], garnet [8 (O) basis], epidote [12.5(O) basis], plagioclase [8(O) basis],
	ilmenite [3(O) basis], sphene [5(O) basis] and apatite [26(O) basis] for mica schist sample AW 44
		D	D	D	D	D	D	D	D	D	D	D	D	D
		3 M ic	3 M ic	3 M ic	3 M ic	3 M ic	3 M ic	2 M ic	2 M ic	2 M ic	2 M ic	2 M ic	2 M ic	2 M ic	Il m	Il m	P l	C h l	C h l	C h l	C h l	S p h	E p	Q t z	Q t z	A p
		a	a	a	a	a	a	a	a	a	a	a	a	a
	Si O 2	4 8. 0	4 8. 1	4 8. 3	4 7. 9	4 8. 0	4 7. 9	5 0. 0	4 9. 2	4 9. 6	4 9. 1	4 9. 7	4 9. 3	4 8. 9	0 . 0 2	0 . 0 1	6 4 . 6	2 4 . 2	2 5 . 2	2 4 . 7	2 5 . 8	3 0 . 1	3 7 . 8	9 8 . 5	9 8 . 7	0 . 0 2
	Ti	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.	0.
	O	4	3	3	4	3	2	1	2	2	2	3
	2	1	1	4	4	1	9	6	7	5	0	6

3.

--------

Acknowledgements

This work constitutes a part of the Doctoral dissertation of the first author. The author acknowledges the Indian Institute of Technology Kharagpur for providing her with fellowship for the work. We put on record the help provided by Debarun Dutta in organising the initial fieldwork in the areas neighboring Godhra and Chhota Udepur during the pandemic. NS acknowledges the School of Earth, Ocean and Atmospheric Sciences, Goa University for the collaborative work. EPMA analyses were performed using the Science and Engineering Research Board (SERB) funded (IRPHA grant no. IR/S4/ESF-16/2009) National Facility in the Department of Earth Sciences, Indian Institute of Technology Bombay (India). PN acknowledges financial support through a Core Research Grant (CRG grant no. CRG/2019/000812) by the SERB. The manuscript was greatly benefitted from the incisive comments and the observations of two anonymous journal reviewers. We acknowledge the Editorial handling of the manuscript by Nadia Malaspina.

APPENDIX A. Mineral chemistry

Mineral chemical analyses were carried out with a CAMECA SX-FIVE Electron Probe Microanalyzer at the Department of Earth Sciences, IIT Bombay (India). The analyses were performed using an accelerating voltage of 15 kV with a beam current of 20 nA. The elements (Si K a , Ti K a , Al K a , Fe K a , Mg K a , Mn K a , Na K a , Ca K a , K K a , P K a , Zn K a , and Ba L a ) were J o u r n a l P r e -p r o o f Journal Pre-proof calibrated using Natural and synthetic mineral standards. Matrix absorption corrections were performed using the X-PHI method [START_REF] Merlet | Quantitative Electron Probe Microanalysis: New Accurate Φ (ρz) Description[END_REF]. The peak and background counts were measured for 20 s and 10 s, respectively. The overlap correction of Ba L a on Ti K a was corrected using the CAMECA Peak Sight software (version 6.1).

B. Whole rock geochemistry

Whole rock major element analyses of samples AW 142A [Figs. (2a,3b,d,and 7a)] and AW 44 (Supplementary Material 3 ) was performed at ACME Lab, Bureau Veritas, Vancouver, Canada.

The protocol is listed in Appendix C of the accompanying article (Banerjee et al., 2022a).

The bulk rock composition for sample AW 372 (Fig. 2b,7b,c) was analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES; SPECTRO-ARCOS simultaneous ICP) at the Sophisticated Analytical Instrument Facility, IIT Bombay. The rock chips were cleaned and powdered to a grain size of <75 µm with a HERZOG pulverizing mill.

The powders of lithium metaborate (0.75 g) and lithium tetraborate (0.50 g) were mixed with 0.25 g of rock power in a platinum crucible, and fused at 1050 °C for 10 minutes in a muffle furnace. On cooling to 800 °C, the ignited mixture was transferred to a 100 ml glass beaker containing 80 ml of 1N HCl solution. After dissolving completely, the samples and standards were diluted (10 times) and transferred to a 100 ml volumetric flask. The instrument calibration was performed using the USGS reference materials (SDC-1, BIR-1, BHVO-2, BCR-2, GSP-2, RGM-2). Standard AGV-2 was run as an unknown to monitor drift in the instrument during analyses. Loss on ignition (LOI) values were estimated by heating rock powders at 950 °C for 10 minutes, then after cooling down to room temperature in a desiccator.

J o u r n a l P r e -p r o o f

Supplementary Material

Supplementary Material 1 : Electron probe micro-analytical data and structural formulae of