Metamorphic Evolution of the Garnet Amphibolite Schist from Mawat Ophiolite, Kurdistan Region, Northeast Iraq: Geochemistry, Mineral Chemistry and Thermodynamic Approach

Abstract


Introduction
The Zagros orogenic belt (ZOB) in the Kurdistan region of Iraq was a response to the convergencecollision cycle of the Arabian and Iranian plates during the Cretaceous to Eocene (Takin, 1972;
The Imbricate Zone in the Kurdistan Region of Iraq comprises various tectonic slices, including Qulqula radiolarite, Mawat Ophiolite Complex, and Walash-Naopurdan volcano-sedimentary groups (Agard et al., 2005;Jassim and Goff, 2006;Ali et al., 2013).It is bound to the east by the Main Zagros Reverse Fault and to the west by the High Zagros Fault (Berberian, 1995).Geochronological studies of the liner ophiolite belt in the Imbricated Zone from southeast to northwest in the Kurdistan region of Iraq reveal a synchronous formation time in addition to their cogenetic nature (Aswad and Elias, 1988;Ali et al., 2012;Mohammad and Cornell, 2017;Mohammad et al., 2021).
The whole Mawat complex consists of two successive thrust sheets (Fig. 2).The main one is the Upper Cretaceous Mawat Ophiolite, and the other is the Paleogene Walash-Nouprdan Groups.The boundary between both units is tectonic and represented by high-deformed mylonitic gabbro in the area (Azizi et al., 2013).It was displaced about 25 km southwest ward onto the Tertiary clastic Red Bed Series.The upper Mawat ophiolite is the largest ophiolite block, with the entire Imbricated zone having an exposed surface area of about 250 km 2 .Field relationships show that the ophiolite is apparently overturned with local thrust faults within the sequence units, from thin and highly deformed and pillow basalts at the base, through 2km thick metagabbros, to peridotite at the top of the sequence.The gabbro consists of lower-level gabbro consists mainly of cumulate gabbro, which is felsic minerals separated from gabbro by local metamorphism and deformation, and it is over thrusted upon the pillow basalt.Layers based on grain size and composition are both present, which may suggest magmatic or metamorphic differentiation.The upper level gabbro is more varied.It includes strongly deformed and mylonitized gabbro, hornblende pegmatoid, and uralitized gabbro (Mohammad et al., 2016).The intensity of dynamic deformation diminishes from mafic to ultramafic units, restricting the greatest area of deformation to the gabbro's marginal zone.
Fig. 1.Geological map represents the main tectonic units from the NE Iran to SW Iraq: 1) The Urumieh-Dokhtar magmatic assemblage, 2) the Sanandaj-Sirjan zone, 3) Imbricate Zone, and 4) the Zagros Fold-Thrust Belt (Le Garzic et al., 2019), the location of the ophiolites in Kurdistan Region of Iraq The lower Paleogene Walash-Naopurdan thrust over the red bed series (Al-Mehaidi, 1975), and this unit was classified into two sequences: the first is the Naopurdan sequence, which is comprised of flysch sediments, and the second is the Walash (Fig. 2a).These rocks consist of volcanic and sedimentary successions.The volcanic units include diabase, metadiabase, spilitic basalt, and other andesites, while the sedimentary units include carbonates, mud rocks, and siltstone.The isotopic analysis revealed that the volcanic unit of Walash was formed from upper mantle rocks and the age of walash 43 Ma (Koyi, 2009;Ali et al., 2013).The study area is in the Kurdistan region, around 30 kilometers north of Sulaimani city and 1 kilometer north of Konjrin village.It is located at 35°19'53" and 35°49'46" N, and 45°02'57.53" and 45°29'07" E. The area is occupied by three types of gabbroic rocks: marginal gabbro, which is situated near the main shear zone, more deformed due to thrusting, light green to dark green in color, and has a medium to low toughness.The second is layered gabbro, which covers most Mawat Ophiolite and has both grain size and compositional layers.The third is pegmatoid gabbro near the ultramafic section, which occurrs as dikes (Al-Saffi et al., 2012).On the field scale observation, the mafic unit of the Mawat complex generated mylonitic fabric and crushed gabbro with varied strain rates in brittle and ductile zones, with clearly visible stretched lineation and sigmoid.
The garnet amphibolite schist occurs as a lenticular body within metagabbro (sheared gabbro) in the shear zone of the Mawat ophiolite (Fig. 3d), which is situated between two tectonic slices, being bounded by the Mawat ophiolite in the east and the Walash Nouprdan volcano sedimentary rock unit in the west.This rock consists of fine to medium grains of chlorite and amphibole with large grains of garnet.The garnet amphibolite schist, with a maximum width of about 5 m and a 15 m length, is hosted by the patch of metagabbro (Fig. 3d).Dark red and brownish-red dodecahedron garnet crystals ranging in size from a few millimeters to 3 cm, scattered within garnet chlorite schist are common (Fig. 3c).This garnet amphibolite schist has previously not been recognized in this area.A lenticular garnet amphibolite schist located within the metagabbro of Mawat Ophiolite and a pod of metagabbro rock with the same physical, optical, and chemical characteristics as surrounding rocks (Fig. 3e), located within the center of the garnet amphibolite schist display as a result of the metamorphism of gabbro to schist and remain a part of it as granite veins nearby.The enclosing metagabbro rock underwent intensive deformation and metamorphosis.A thin layer of felsic minerals appears within the metagabbro, close to the garnet amphibolite schist and metagabbro contact (Fig. 3b).

Materials and Methods
Twenty-six samples were collected from the study area in four field trips from October 2020 to March 2021.Twenty samples from garnet amphibolite schist and six from host rock metagabbro were selected on the basis of a parent modal mineral variation and color changes (Fig. 2b).Four hundred grams of garnet were separated from the garnet amphibolite schist, ranging in size from a few millimeters to several centimeters for single mineral geochemistry, inclusions, and petrography studies.<1 1 3 <1 1 <1 <1 1 2 3 1  Forty thin sections and five polished sections of garnet amphibolite schist and metagabbro were prepared in different directions to show a three-dimensional mineral distribution in the rocks.Using transmitted light microscopy for petrographic study.Three powder rock samples were analyzed using the Malvern Panalytical X-Ray Diffractometer (XPERT-PRO diffractometer) instrument at the University of Sulaimani-Department of Geology.
For whole-rock analyses based on a careful petrographic study of thin sections of garnet amphibolite schist and gabbro, 11 representative samples were chosen for major, trace, and rare earth element (REE) analysis.The analysis was done by X-Ray fluorescence (XRF), ICP-AES, and ICP-MS analysis at the ALS laboratory, Sevilla, Spain.The geochemical results are given in Tables (1, 2 and 6).Chemical compositions of representative minerals from the garnet amphibolite schist associated with Mawat ophiolite are analyzed at TU Bergakademie Freiberg using a JEOL-JXA 8900RL electron microprobe.Operation conditions involve the acceleration voltage was 15 kV and the beam current was 20 nA with the beam focused on a 2 µm diameter spot.Representative mineral compositions of garnet, plagioclase, amphibole, chlorite, and iron oxide are given in Tables (3, 4, and 5).
Geo-Pseudo 3 Section (Xiang and Connolly, 2021) thermodynamic software was used to figure out and predict stable mineral assemblages and their modal percentages based on the geochemistry of the whole rock.

Host rock
Petrographic examination reveals that the main minerals constitute of the host rock (Fig. 4a) consist of anhedral plastically deformed plagioclase (40-45% vol.), coarse grain amphibole (30-35% vol.), medium deformed grains of pyroxene (10-15% vol.), pale green chlorite (0-5% vol.), and subhedral to anhedral iron oxide (2-5% vol.).Mylonitic texture is the typical texture in the rock.Porphyroblastic and poikilitic textures with phenocrysts of amphibole containing smaller grains of plagioclase are common (Fig. 4b), suggesting the protolith probably was coarse-grained gabbro.In the middle of the garnet chlorite schist, the relict assemblage of host rock has been preserved as a small pod.It is made up of the identical assemblage of minerals that the protolith was metagabbro.The pod could be unmetamrphosed protolith of garnet chlorite schist.

Garnet amphibolite schist
The dominant mineral assemblage of the garnet amphibolite schist (retrograde eclogite) at the prograde stage is euhedral to subhedral coarse grained, highly fractured, garnet surrounded by green chlorite, and recrystallized coarse grain plagioclase surrounded by fine grains.Acicular elongated amphibole with euhedral iron oxide is common.Prismatic amphibole with preferred orientation show nematoblastic texture (Fig. 4c).In the prograde rock, the porphyroblastic garnet contains abundances patches and inclusions of acicular to prismatic colorless and light green amphibole (Fig. 4d), corroded plagioclase (Fig. 4e) and euhedral to subhedral iron oxide either as inclusion or as a matrix mineral.The retrograde mineral assemblage is garnet, chlorite and iron oxide with absent of plagioclase either as inclusion or in the matrix.Thus, the boundary between prograde and retrograde is present and absent of plagioclase (Fig. 4g and h).Moreover, the volume percentage of chlorite and amphibole increases in the rock, in addition, the sizes and numbers of inclusions of garnet decrease.The main inclusions in this stage are colorless to light green amphibole and euhedral to subhedral iron oxides (Fig. 4d).Generally undeformed porphyroblastic garnet shows "S"-shaped inclusion trails of acicular amphiboles, suggesting syn-tectonic (kinematic) types of garnet (Fig. 4f).

Granite veins
The mineralogy of nearby granite is very simple.It consists of more than 90% coarse grains of highly deformed albite with a minor amount of amphibole.The accessory is fine grain zircon.The boundary between granite and host rock is very sharp, suggesting it represents late stage intrusion.

Plagioclase
Plagioclase is the primary mineral in the garnet amphibolite schist at the prograde stage of metamorphism, as it is commonly observed in the zone near the center of garnet amphibolite schist rocks.It either occurs as patches within the garnet porphyloblast or as unhedral grains in the matrix.The chemical composition of plagioclase is mostly more anorthosite, with Xan (94-99%), Xab (1-3%), and Xor less than 6% (Fig. 5b).Microprobe data revealed high SiO2 (38.4-44.5% wt.), Al2O3 (33.6-36% wt.), , and low Na2O (0.1-0.7% wt.) and K2O (0.01-0.1% wt.) contents (Table 4).Generally, Al2O3 shows a few differences in both generations, such that it is slightly more calcium in the patches.No chemical zoning exists on grain scales.

Chlorite
Chlorite is the most dominant mineral in garnet amphibolite rock samples.The modal abundance in retrograde garnet amphibolite schist.Chemical analysis shows the composition of chlorite as follows: SiO2 (21.7-32.3%wt.),  (Table 4).According to Zane and Weiss (1998), the chlorite composition is located at the boundary solid solution between clinochlore and chamosite, suggesting identical examples of chlorite solid solution (Fig. 7b).Thus, it may indicate chamosite has been in equilibrium with pyrope components of garnet and clinochlore in equilibrium with almandine components of the garnet grains according to the following reaction (Dickenson and Hewitt, 1986).5Fe3Al2Si3O12 + 3Mg5Al2Si3O10(OH)8 = 5Mg3Al2Si3O12 + 3Fe5Al2Si3O10(OH)8 Almandine clinochlore pyrope chamosite (1)
The garnet amphibolite schist rocks show extreme depletion in SiO2 content, ranging from 26.5 to 29.3% wt. in contrast to the protolith, which has 46.6-48.4% wt.(Table 1).This may be attributed to the generation of silicic melts by the partial melting of gabbro that is significantly tied to the event of increased pressure at shear zones in the ophiolites (Koepke et al., 2004).The occurrence of an extensive network of felsic rock in sheard gabbro may support that.High values of FeO t content ranging from 30.7 to 32.4% wt. and values of Al2O3, and MgO ranging from 19.05 to 20.3% wt. and 11.35 to 14.35 wt.% respectively.This is due to very high modal volume percentage of ferromagnesian of garnet, amphibole and chlorite within the rock, in addition the rock depleted in CaO content (0.6 -1.34% wt.).The CaO depletion may be related to the absence of plagioclase in retrograde mineral assemblage.The increase of refractory elements in resitite and depletion in the melt are identifying features of the partial melting of gabbroic rock.
The field zones on the ACF diagram described the development of resitite and melt along the boundary between three contrasting rock types; garnet amphibolite schist (restite), gabbro, and plagiogranite (granite veins) (Fig. 8b).The gabbro in the ACF diagram shows it has nearly equal content to ACF.Meanwhile, the plagiogranite shifted toward the A apex of the diagram, indicating that it is depleted in FeO and MgO and enriched in SiO2 as compared to restite, assumed to be generated by partial melting of pre-existing basic rocks (Mirza and Ismail, 2007).Sometimes partial melting is related to high-temperature shearing zone (Malpas, 1979;Pedersen and Malpas, 1984;Spray and Dunning, 1991).The garnet amphibolite schist (restite) located below the field of protolith on the ACF diagram indicates that the rock is enriched by FeO, in addition to the depletion of SiO2 and CaO, in contrast to the protolith (gabbro).The depletion of CaO in restite and silicate melts may suggest that the CaO is more mobile and separate from the melting system and combines with the CO2 to produce the carbonate veins that are more common in the area.

REE and trace elements
The REE concentrations of garnet amphibolite schist, metagabbro, garnet, and plagiogranite were normalized to chondrite meteorite (Fig. 9), which was used by Sun and McDonough (1989).
From the relationships between chondrite-normalized patterns for garnet amphibolite schist, associated plagiogranite, and metagabbroic rock, samples showed a gradient in the light rare earth elements (LREE) and parallel in the HREE with strongly fractionated pattern.The pattern of samples shows that the garnet amphibolite schist is depleted in LREE and gradually enriched in HREE.This is due to the compatibility of HREE in the garnet crystal structure.In contrast, plagiogranite (granite vein) samples are strongly enriched in LREE (LREE enrichment of granite reaches 8 -70 times the chondritic level) and gradually decreases to HREE, which suggests that these rocks have formed from partial melting of same rock (gabbro).The high LREE in plagiogranite is related to the dominance of albitic plagioclases.Negative Eu anomalies were observed in some samples of garnet amphibolite schist and individual garnets.They are related to the behavior of Eu with Ca up on melting, the Eu may partially inter the granitic melt and the resitite will be depleted in Eu.
The partial melting process enhances the mobilization of some important trace elements between the resitite and the melt.The analysis shows a clear comparison between garnet amphibolite schist and plagiogranite in terms of compatible elements (Ni, Co, Cr, and Sc), which are strongly enriched in garnet amphibolite schist compared to plagiogranite, while incompatible elements, especially the large ion lithophile elements (LILE) of large ionic radius, like Rb, Ba, and Sr, are depleted in resistant rock (garnet amphibolite schist).In melting, some elements tend to be concentrated in silicic melts (plagiogranite).The high-field strength elements (HFSE) such as Th, Nb, and Zr with other incompatible elements like La and Pb are highly enriched in plagiogranite, while depleted in garnet amphibolite schist.

Thermodynamic modeling and effective bulk composition
The goal of P-T pseudosection modeling is to develop a mineral equilibrium model in which various metamorphic mineral assemblages are predicted to attain equilibrium within a given pressuretemperature (P-T) range, based on a given bulk-rock composition of interest (Holland and Powell, 1998;White et al., 2007;Clark and Hand, 2010).Table 7 shows the bulk-rock composition as determined by XRF analysis and the calculated molecular ratios for phase equilibrium modeling of the garnet amphibolite schist and protolith (metagabbro) DA3 and DA7, respectively.
The pressure-temperature pseudosection metamorphic development of the garnet amphibolite schist and effective bulk composition were constrained by a computed P-T phase diagram, Geo-Pseudo 3 Section (Xiang and Connolly, 2021), for the chemical systems Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-TiO2 and H2O (NCKFMASTH) for metagabbro and Na2O-CaO-FeO-MgO-Al2O3-SiO2 and H2O (NCFMASH) with the internally consistent thermodynamic data set, ds62, of Holland and Powell (2011), and calculation isopleths (stability field of each mineral) to obtain the metamorphic conditions.Based on the petrography and mineral chemistry investigations mentioned above, MnO and P2O5 accounted for a very small proportion of the total rock composition of metagabbro.In addition to garnet amphibolite schist, K2O and TiO2 were removed from the calculation.Furthermore, iron oxide and H2O, both supposed to be fluid phases, are thought to be in excess.The pseudosection is calculated at temperatures ranging from 500 to 1000 °C and pressures ranging from 1 to15 kbar for sample DN7 and 400 to 700 °C and pressures ranging from 0.5 to 5 kbar for sample DA3.Mineral chemistry and petrography reveal that this garnet amphibolite schist has preserved both prograde and retrograde mineral assemblages of the P-T history.The prograde mineral assemblages are amphibole, garnet, chlorite, and plagioclase; and the retrograde mineral assemblage is amphibole, garnet, chlorite, and iron oxides.The boundary between the prograde and retrograde stages is determined based on the presence or absence of plagioclase in the assemblage as stable or metastable phases.We envisage two scenarios for these mineral assemblages: The first is calculated for the garnet amphibolite schist bulk composition (Fig. 10a).Considering garnet amphibolite schist as the effective bulk composition, thermodynamic calculations cannot predict the actual mineral assemblage observed in the rock's thin sections.This might suggest that they added or removed chemical elements during metamorphism, or that the rock originated from different bulk compositions rather than the effective bulk garnet amphibolite schist composition through allochemical metamorphism.The thermodynamic model of the bulk garnet amphibolite schist composition under variable P-T conditions shows that the fayalite should be stable over the whole P-T condition in the association of variable mineral assemblages.Meanwhile, the fayalite was neither observed in garnet amphibolite schist or parent metagabbro, suggesting this scenario is less likely for origin of garnet amphibolite schist in the area and suggesting that the garnet amphibolite schist composition not reflecting the original rock composition.
The second scenario is calculated for the bulk composition of gabbro (metagabbro) (Fig. 10b), which occurs as relict lenses in the center part of the garnet amphibolite schist.For effective bulk composition, different mineral assemblages occur in various P-T conditions over the whole P-T range.At the right corner, the high temperature (800-950 °C) and low-pressure (less than 4 kbar) mineral assemblage of metagabbro were stable (main minerals of metagabbro (amph+ pl+ px)).With increasing temperature and pressure, the rock partially melts and produces a granitic melt and prograde resitite (grt+ chl+ amph+ pl+ ironoxide).The restite assemblage is stable at temperatures ranging from 620 to 650 °C and pressures ranging from 6.5 to 6.8 kbar (Fig. 10b).On separation of granitic melt to form plagiogranite later from the protolith, the restite portion of the rock (garnet amphibolite schist) underwent retrograde condition at lower condition on uplifting during the obduction of Mawat Ophiolite over the Arabian continental margin.According to the thermodynamic modeling, the current mineral assemblage (grt+ chl+ amph+ iron oxide) is unstable and the pressure is greater than 4 kbar and the temperature is less than 600 °C.The rock's thermodynamic modeling reveals an anticlockwise metamorphic evolution (Fig. 10b).The presence of extensive veins of plagiogranite in addition to resitite mineral assemblages supports the second scenario for the origin of garnet amphibolite schist in the area.

Mineral Stability Fields
We computed the stability of observed phases for effective metagabbro bulk compositions as follow:

Stability of Garnet
The Xalm isopleths of the garnet growth during the P-T path were contoured (Fig. 11a) and they are increasing with decreasing temperature and pressure from Xalm 0.2 at a high temperature of more than 800 °C and a high pressure of more than 8 kbar to Xalm 0.7 at a lower pressure.On the other hand, XPrp increases with increasing temperature and pressure, which means pyrope is mostly formed when rock is partially melted.The contours show that garnet is unstable below 6 to 8 kbar.This shows the garnet is directly unstable below the mineral assemblage (amph+ chl+ gt+ pl) condition, and the garnet may be replaced by chlorite.According to the phase diagram, garnet is possibly stable at low and high temperatures with different endmembers at high temperature pyrope is stable and at medium and low temperature almandine is stable.

Stability of Plagioclase
The thermodynamic modeling stability contours indicate plagioclase is unstable at high pressure (Fig. 11b), and the isopleth of Xan is increasing at temperatures ranging from 600 to 800 °C.Plagioclase is stable in the P-T condition of (gt+ chl+ amph+ pl) assemblage at 620 to 650 °C and 6.5 to 6.8 kbar with Xan larger than 0.9.As a result, plagioclase is absent from the retrograde mineral assemblage.This suggests that the current P-T conditions of the rock pressure are greater than 4 kbar, because plagioclase formed with Xan is less than 0.9 at lower pressures.

Stability of Chlorite
The clinochlore isopleth P-T constraint methods (Fig. 11c), which also provide the phase equilibrium condition, demonstrate the effect of P-T on mineral distribution.Chlorite is the dominant stable mineral at low temperatures and absent or unstable at high temperatures, according to the isopleth of clinochlore on the phase diagram, and it forms at both high and low pressure.The clinochlore isopleth depicts the highest volume of clinochlore present at the stable zone of mineral assemblage (grt+ chl+ amph+ pl) at temperatures ranging from 600 to 650 °C and pressures ranging from 6 to 8 kbar.Garnet appears to be unstable at temperatures less than 600 °C and low pressure, and is replaced by chlorite.Omer et al. 2023, 56 (1A), 127-148 146

Combination of minerals with stability fields.
The stability zones of different minerals (garnet, chlorite and plagioclase) indicate that the mineral assemblages (grt+ chl+ amph+ pl) are stable, ranging from 600 to 650 °C and pressures ranging from 6 to 8 kbar (Fig. 11d).The coexistence of these stable assemblages only restricted to certain P-T-t path on the psudosection diagram, may suggest the protolith reached the eclogite facies later retrograded to upper amphibolite.The garnet isopleth shows that the garnet is stable at high temperature, whereas plagioclase and chlorite are stable at low temperature.

Conclusions
The garnet amphibolite schist in the research area is associated with the mafic unit of the Mawat Ophiolite.Two metamorphic stages are recognized for the garnet amphibolite schist, consisting prograde stage, emphasized by garnet (almandine)+ chlorite (clinochlore)+ amphibole (grunerite)+ plagioclase (anorthite)+ iron oxides, retrograde stage indicated by garnet (almandine), chlorite (chamosite), amphibole (cummingtonite), and iron oxide.The pod of the metagabbro preserved in the center of the rock is primarily composed of plagioclase, amphibole, pyroxene, and iron oxide.Thermodynamic modeling, combined with petrographic observations and the construction of isopleths on the pseudosection in the model system NCKFMASTH, constrain the possible anticlockwise P-T-t path for the garnet amphibolite schist.The early prograde stage, the temperature is more than 800 °C and the pressure is 8-10 kbar, which caused the rock to partially melt.The resitite rock with the (grt+ chl +amph +pl +iron oxide) assemblage is stable at temperatures ranging from 620 to 650 °C and pressures ranging from 6.5 to 6.8 kbar.The current mineral assemblage in the state is unstable.The geochemical data and thermodynamic modeling indicate that gabbro is the protolith of garnet amphibolite schist.

Fig. 2 .
Fig. 2. a) Geological map of the Mawat ophiolite depicting different units of the area (Al-Mehaidi, 1975); b) A sketch illustrates the sample locations of the garnet amphibolite schist and associated rocks

Fig. 3 .
Fig. 3. a) Google earth image of the study area showing different units; b) Granitic veins in the vicinity of garnet amphibolite schist; c) Photographs show different size of dark red and brownish-red dodecahedron garnet; d) lenticular garnet amphibolite schist within metagabbro; e) the pod of meta gabbro in the center of the garnet amphibolite schist.

Fig. 4 .
Fig. 4. Photomicrograph showing the main textural and minerals in garnet amphibolite schist and metagabbro; a) Main mineral constituent of gabbro; b) Poikiloblastic textures with porphyroblasts of amphibole containing smaller grains of plagioclase; c) Nematoblastic texture; d and e) inclusions of amphibole, plagioclase and iron oxide within porphyroblasts of garnet; f) Porphyroblastic garnet show "S"-shaped inclusion trails; and g and h) scaned thin sections of prograde and retrograde minerals assemblage.

Fig. 10 .
Fig. 10.P-T pseudo-sections calculated based on the effective bulk compositions illustrating the metamorphic evolution of garnet amphibolite schist indicate the P-T conditions; a) using bulk composition of garnet amphibolite schist sample DA3 and; b) using bulk composition of metagabbro (protolith) sample DA7

Fig. 11 .
Fig. 11.Pseudo-section of the rock using bulk composition of metagabbro calculated with Geo-Pseudo 3 Section in the model system NCKFMASTH.(a) Pseudo-section with isopleths of almandine garnet, (b) Pseudo section with isopleths of plagioclase based on anorthite endmember, c) Pseudo section with isopleths of chlorite based on clinochlore endmember, d) stability zone of different minerals on the P-T diagram show stable assemblage of garnet amphibolite schist.

Table 3 .
Representative analysis of garnet from garnet amphibolite schist of the Mawat ophiolite

Table 5 .
Representative analysis of amphibole from garnet amphibolite schist in Mawat ophiolite.

Table 7 .
Bulk-rock composition of the garnet amphibolite schist and metagabbro from the Mawat ophiolite area used for thermodynamic modeling.