Metamorphism of Pelitic Rocks (Metapelites). A well-documented example of a Barrovian-type metamorphic zoning is exposed on the island of Naxos, Greece (see later). Kyanite and sillimanite are also present and make the Sure Formation distinct from the Jaishidanda Formation. Metamorphic facies. Rocks which contain certain minerals can therefore be linked to certain tectonicsettings, times and places in the geological history of the area. The duration of granulite (G) and ultra–high temperature (UHT) conditions in regional metamorphism is critical to arguments regarding the tectonic settings of … Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. Some of the gneisses are confined to the lower plates of two Cretaceous metamorphic core complexes in the South Island (stars in Figure 2). If both chlorine and CO2 contents are high, then it is likely that immiscible CO2-rich and chlorine-rich fluids would coexist at high P and T (Duan et al., 1995; Schmidt and Bodnar, 2000), consistent with fluid inclusion evidence for multi-phase granulite facies fluids (Touret, 1985; Crawford and Hollister, 1986). Granulite facies metapelite, biotite gneiss and metabasic gneiss in Namaqualand contain coarse‐grained, discordant, unfoliated, anhydrous segregations, surrounded by a finer grained, foliated matrix that commonly includes hydrous minerals. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL: https://www.sciencedirect.com/science/article/pii/B9780128020210000085, URL: https://www.sciencedirect.com/science/article/pii/B0123693969003191, URL: https://www.sciencedirect.com/science/article/pii/S0166263504800057, URL: https://www.sciencedirect.com/science/article/pii/B9780128098394000047, URL: https://www.sciencedirect.com/science/article/pii/B978012804441400002X, URL: https://www.sciencedirect.com/science/article/pii/B0123693969003920, URL: https://www.sciencedirect.com/science/article/pii/B9780128044414000067, URL: https://www.sciencedirect.com/science/article/pii/B0080437516030231, URL: https://www.sciencedirect.com/science/article/pii/B0123693969003907, URL: https://www.sciencedirect.com/science/article/pii/B9780124095489095476, Clark, Collins, Kinny, Timms, & Chetty, 2009, Regionally extensive metamorphic overprints include Devonian and Cretaceous polymetamorphic amphibolite–, Several studies have attempted to correlate and compare the widespread mid-Mesoproterozoic, Henderson, Collins, Payne, Forbes, & Saha, 2014, Vijaya Kumar, Ernst, Leelanandam, Wooden, & Groves, 2009, Bose, Dunkley, Dasgupta, Das, & Arim, 2011. 6.12) in the following stages: (1) 1.7–1.5 Ga: Archean cratons (Dharwar, Bastar, and Napier) became sutured by fringing orogens (Karimnagar-Bhopalpatnam, CITZ, EGMB, Kemp Land), followed by narrow divergence of the Napier Craton from the Indian composite, (2) 1.3–0.9 Ga: initial 1.3 Ga convergence of India and Antarctica proceeding to final 1.0–0.9 Ga collision during the assembly of Rodinia. Leucogranulites from the Bohemian Massif. Tourmaline is associated with leucocratic granite variety. They also observed that reaction textures and geothermobarometry indicate high-temperature decompression of the upper portion of the Tibetan Slab to nearly 4 kb from a higher pressure. In view of this, a feasible explanation for the inferred stability of the supercontinent during the early Palaeoproterozoic and for the scarcity of subduction events along its margins, may lie in the assumption of intensive recycling of juvenile oceanic and young arc-related crust within the oceanic hemisphere (cf. Geochemical signatures of metasedimentary rocks of high-pressure granulite facies and their relation with partial melting: Carvalhos Klippe, Southern Brasília Belt, Brazil. 10. The P–T–t evolution of the exhumed Himalayan metamorphic core in the Likhu Khola region, East Central Nepal. Variations in fluid activity across the Etive thermal aureole, Scotland: evidence from cordierite volatile contents. The above-mentioned features indicate that the EGMB-south may represent an exotic terrane accreted to the Indian craton at c. 1.6 Ga, as a fragment of the Napier Complex of Antarctica and simultaneously connected to parts of Proterozoic Australia. Finally, Muir et al. The geochemistry and geochronology of the upper granulite facies Kliprand dome: comparison of the southern and northern parts of the Bushmanland Domain of the Namaqua Metamorphic Province, southern Africa and clues to its evolution. The amphibolite to granulite facies rocks overlying the MCT occupies a vast expanse of Bhutan and is named the Thimphu Group/Great Himalayan Zone/HHC/Tibetan Slab (Fig. The spatial and temporal patterning of the deep crust and implications for the process of melt extraction. Accessory Mineral Behaviour in Granulite Migmatites: a Case Study from the Kerala Khondalite Belt, India. The assemblage is typical of what is formed in conditions corresponding to an area on the two dimensional graph of temperature vs. pressure (See diagram in Figure 1). The reworking of granulite facies rocks of the region was correlated and a possible linkage between both the domains was suggested (Dasgupta & Sengupta, 2003). 7.3 Plate Tectonics and Metamorphism – Physical Geology Thus, if we know the facies of metamorphic rocks in the region, we can determine what the geothermal gradient must have been like at the time the metamorphism occurred. Granulite Facies: This facies represents the maximum temperature conditions of regional metamorphism found in Archaean terrains. The LSL is positioned at the central region of the HHC, much higher up from the MCT. Pan-African extension and near-isothermal exhumation of a granulite facies terrain, Dronning Maud Land, Antarctica - Volume 141 Issue 6. Exhumation of the Haast Schist belt was episodic, with most of the schist being at the surface by 105 Ma and deeper levels being exhumed along the Alpine Fault from 20 Ma to the present day. The proof of the presence of a single continuous belt of rocks also comes from the occurrences of the trails of the coevally metamorphosed Archaean granite-greenstone belt rocks showing a metamorphic state compatible with the enclosing granulite bodies along with the Peninsular Gneiss, meta-basaltic dykes of different generations, and their granulitic equivalents well within the massifs of Biligirirangan, Coorg, and Nilgiri Hills in the south (Rama Rao, 1940; Janardhan, 1983). The granulite-facies metamorphism with peak P-T conditions at 718–729 ºC and 0.46–0.53 GPa is characterized by an anticlockwise P-T path. In the early 1980s it was realized that the Mesozoic Rangitata Orogeny was probably a composite of an older subduction-related event and a younger extension-related event. At higher levels, the granite gneiss rock is replaced by augen gneiss, which contains large feldspar porphyroblasts, and biotite content is more than in the lower level Sure gneiss. An interesting information favouring continuity of Dharwar belt further south comes from the study of trace element chemistry of charnockites and the associated granites (Mahabeleshwar and Peucat, 1988; Mahabeleshwar et al., 1995). They may represent a continuation of the Calvert and Isa superbasins that has subsequently been displaced dextrally during the Mesoproterozoic (Figure 3). (HP) granulite facies and ultrahigh temperature is sparsely pre-served but widely distributed in Phanerozoic orogenic belts and Precambrian cratons (e.g. Mesoproterozoic granulites of the Shillong–Meghalaya Plateau: Evidence of westward continuation of the Prydz Bay Pan-African suture into Northeastern India. 2012; and references therein). The cordierite‐bearing anatectic rocks of the higher Himalayan crystallines (eastern Nepal): low‐pressure anatexis, melt productivity, melt loss and the preservation of cordierite. Santosh & Kusky 2010; Santosh alet. . Minor quartzite bands and few-meter-thick layers of amphibolite are reported to occur at different tectonic levels of the Naspe Formation. 248-257. The so-commonly observed high T, low P phase (M2) at the high levels of the HHC, according to them, might have an initial stage of higher T and P. Pecher and Le Fort (1986) incorporated the work of Gansser (1983) in their metamorphic map of Central Himalaya (see Fig. It has been regarded as consisting of three tectonic events and dates from ∼1850 to ∼1690 Ma. Lithology Tectonic setting Tectonometamorphic history Heat-production rate (μW m-3) Area wtd. The preservation of anhydrous assemblages and the restricted distribution of late hydrous minerals suggest that retrograde reaction between hydrous melt and solids did not occur and that H2O in the melt was released as vapour on crystallization. Anatectic melt volumes in the thermal aureole of the Etive Complex, Scotland: the roles of fluid‐present and fluid‐absent melting. Besides, the mafic granulite lenses hosted within the opx–ksp gneiss also show a metamorphic age of ∼255 Ma (Chen et al., 2006). Harlov et al., 1997; Smit and Van Reenen, 1997). In most of the Rodinian reconstructions, the eastern margin of India is juxtaposed against East Antarctica with the Rayner complex being correlated with the EGMB (e.g., Yoshida, Funaki, & Vitanage, 1992). The upper segment of the sequence contains migmatitic gneisses, leucogranite, and high-grade metasedimentaries, while the lower part is composed of quartzite, schists, paragneiss, and granite orthogneiss. Equilibria involving melt and solid phases are effective buffers of aH2,o. ... granulite facies of high-pressure influences during In the Gawler Craton, Archaean gneissic rocks of the Sleaford and Mulgathing complexes were deformed, metamorphosed to, Reference Module in Earth Systems and Environmental Sciences, Most metamorphic terranes, especially in the internal parts of continents, are composed of greenschist, amphibolite, and. We thus postulate that Palaeoproterozoic history can be subdivided into five periods: (1) 2.51–2.44 Ga superplume activity and displacement of Fennoscandia; (2) 2.44–2.0 (2.11) Ga quiescent within-plate development complicated by local plume-and plate tectonics-related processes (see also section 3.7); (3) a 2.0–1.95 Ga superplume event (see also sections 3.2 and 3.3); (4) 1.95–1.75 (1.71) Ga combined plume-and plate tectonics-related evolution, resulting in the partial disruption of the continental crust, and formation of accretionary orogens along some margins of the supercontinent, and rebirth of the supercontinent entity, and (5) < 1.75 Ga post-and anorogenic magmatism and metamorphism. McGraw-Hill. Carbonation of Cl‐rich scapolite boudins in Skallen, East Antarctica: evidence for changing fluid condition in the continental crust. Archaean granulite facies metamorphism in the extreme south of the craton have been reviewed by Hansen et al (1995), among others. The ridges are composed of volcanic mountains that erupt basalt onto the surface of the ocean and by that process create new oceanic crust. Granulite facies amphibole (pargasite) in the olivine gabbro is distinguished from the amphibolite facies amphibole of dykes and gneiss by sodium content that reaches 4.2wt%. Ruby, the red gem variety of corundum, forms during amphibolite- and granulite-facies metamorphism or melting of mixed Al-rich and Si-poor protoliths, 10–40 km deep in the crust. Ukwang, E. E. and Ekwueme, B. N. (2009). time and in different tectonic settings? As the ocean ridges are the predominant conduits for heat loss, it is extremely unlikely that plate tectonics should have stopped and restarted again several times (see also section 3.6). Clockwise, low- metamorphism of the Aus granulite terrain, southern Namibia, during the Mesoproterozoic Namaqua Orogeny. Metamorphism probably took place in the deep parts of a Jurassic–Early Cretaceous accretionary wedge. Geological Magazine, 126, 215-247. In a certain sense, they can be interpreted as the beginning of a new Meso-Neoproterozoic evolutionary cycle. The Sure gneiss is reported to be a two-mica granite gneiss, which is locally migmatitic. The thermal pulse recorded at c. 1600 Ma in the EGMB-south is similar to the reworking of the NRBF in East Antarctica and may indicate a connection involving the EGMB-south and Napier-Rayner complex at this time (Bose, Dunkley, Dasgupta, Das, & Arim, 2011). This new understanding will result directly in decreasing the number of orogenic belts that can be interpreted plausibly as sutures. The Archaean architecture of the complex was completed by intrusion of granite sheets and pegmatites around 2,550 Ma, mainly in the Outer Hebrides. Lamb and Valley, 1984; Crawford and Hollister, 1986; B. R. Frost and C. D. Frost, 1987; Newton, 1995; Aranovich and Newton, 1996, 1997, 1998, and numerous references cited therein). In the northern part of the Oman Mountains in the Bani Hamid area, United Arab Emirates, ~870 m of granulite facies rocks (enstatite + spinel ± diopside quartzites, garnet … Metamorphism and partial melting of high-pressure pelitic granulites from the Qianlishan Complex: Constraints on the tectonic evolution of the Khondalite Belt in the North China Craton. Department of Earth Sciences, University of Cambridge, Downing Street, Rondebosch, 7700 South Africa. This means that assemblages of both facies occur in the same metabasalt. The Namaqualand Metamorphic Complex contains granulite facies rocks formed in two or more thermotectonic cycles during the mid-Proterozoic. On the other hand, the style of crustal evolution during the Palaeoproterozoic differs significantly not only from that in the Archaean, but also from that in the Phanerozoic. Geological Setting of the Bergen Arcs. The leucogranites intruded the country rocks, which were already heated past the second sillimanite isograds and were deformed penetratively. Anatexis during High-pressure Crustal Metamorphism: Evidence from The latest, most widespread and intense event at c.1150 Ma gave rise to low-P granulites which record an anticlockwise P-T path and were accompanied by gneissic granite and charnockite. Isotopic constraints on fluid infiltration from an eclogite facies shear zone, Holsenøy, Norway. Mount Isa) during the Proterozoic. See also Palin et al. Ukwang, E. E. and Ekwueme, B. N. (2009). 2. The geochemical characteristics of granites from the NGB indicate a dominant calc–alkaline nature consistent with their formation in a convergent margin in an island arc setting at around 2.5 Ga. Garnet-bearing paragneiss from the Biligirirangan massif in the southern Karnatak. 4.4. tectonic setting, and its relationship to other similar Australian terranes (e.g. Therefore, it is abundantly evident from the available geochronological data that the EGMB must have been affected by the Neoproterozoic-Cambrian events indicating that the EGMB was juxtaposed against east Antarctica during Gondwana assembly. 8.3). Petrology of an intrusion‐related high‐grade migmatite: implications for partial melting of metasedimentary rocks and leucosome‐forming processes. A. Feenstra, G. Franz, in Reference Module in Earth Systems and Environmental Sciences, 2015. However, muscovite is coarse grained and cuts across the schistosity and was possibly formed during the cooling phase. The second phase of the orogeny produced medium- to high-pressure/high-temperature metamorphism and associated deformation. Granulite Gallery Petrological features of granulites, charnockites and migmatites. All the tectonothermal events in the region including the UHT metamorphism can be considered as part of this accretionary process. Decompression mineral microtextures in granulites of the Irkut block (Sharyzhalgai uplift of the Siberian Platform). The steep mélanges may represent zones of strike-slip deformation. Segregation of leucogranite microplutons during syn‐anatectic deformation: an example from the Taylor Valley, Antarctica. Based on the isotopic, geological, and geochemical similarities, the proposed exotic terrane may represent an extension of the Napier Complex, Antarctica, and possibly connected to Proterozoic Australia (North Australian Craton and Gawler Craton). Roy, Ritesh Purohit, in Indian Shield, 2018. Seemingly disparate temperatures recorded in coexisting granulite facies lithologies. Contradicting the traditional usage, the recent studies help to reinterpret the ‘Fermor Line’ as a metamorphic isograd boundary marking a transition between the upper amphibolite facies and the hypersthene-bearing granulite facies metamorphism in the south (Janardhan, 1983; Srikantappa et al., 2003). Lithologic and geochemical comparisons show that supracrustal assemblages in the amphibolite- and granulite-facies terrains of southern India formed in different tectonic settings and had different sediment sources. Formation and emplacement of two contrasting late-Mesoproterozoic magma types in the central Namaqua Metamorphic Complex (South Africa, Namibia): Evidence from geochemistry and geochronology. de Wit’s intra-oceanic model; e.g., 1998). At higher temperature, amphibolite and granulite are directly replaced by eclogite (lines 5 and 6, in Figure 5). The interpretation was further extended that the EGMB-south represents a part of an exotic terrane, which was transferred to proto-India in the late Paleoproterozoic as part of a linear accretionary orogenic belt that may also have included south-west Baltica and southeastern Laurentia. The retrograde P–T–t path for low‐pressure granulites from the Reynolds Range, central Australia: petrological constraints and implications for low‐P/high‐T metamorphism. Petrological studies of metagabbros from the southwest periphery of the Biligirirangan Block reveal clockwise prograde and retrograde metamorphism in a subduction zone setting at a HP of 18–19 kbar and temperature of ~840°C (Ratheesh-Kumar et al., 2016). Tectonic setting is Arc collision. basins and oassive margins; thick sediments create enough t and p for recrystallization in lower layers, gradient- normal, facies- zeolite (relatively low t and p) ... facies- greenschist, amphibolite, granulite. A variety of mechanisms for generating low aH2O fluids have been proposed, including infiltration of connate brines or fluids equilibrated with metaevaporites, loss of H2O to anatectic melts leaving behind residual fluids enriched in salts and CO2 (Fyfe, 1973; Philippot, 1993), release of brines and CO2 from deep crustal intrusions (Hansen et al., 1995), and loss of H2O to retrograde rehydration reactions (Markl et al., 1998). After Veevers, J.J. (2009). Granulite facies xenoliths from the Yuhuashan complex, central Jiangxi, South China constraints on Late Palaeozoic orogeny and middle-lower crust components Columbia had a long-lived history of subduction related growth via accretion at important continental margins for nearly 500 Myr and a correlation of major accretionary belts of c. 1760–1700 Ma orogenesis around the preexisting cratons involving Laurentia, Antarctica, South Africa, and Australia including the eastern margin of India was proposed (Zhao, Sun, Wilde, & Li, 2004). Charnockitic alteration: evidence for CO2 infiltration in granulite facies metamorphism. (1989): The origins of granulites: a metamorphic perspective. Trace element geochemistry and tectonic setting characterization of granulite facies rocks from southwest Obudu Plateau, southeastern Nigeria. The 90 Ma Kigluaik pluton forms the core of a granulite facies gneiss dome and is Farther north is a granulite facies gneiss complex, the Qinling Group, which has ultramafic slivers and includes the remnants of an island arc with two bounding suture zones. Veevers (2009) summarized and illustrated the assembly and breakup history of Antarctica and India (Fig. The lower amphibolite facies rocks contain kyanite–garnet–biotite–muscovite–plagioclase–quartz–staurolite assemblage, and the higher amphibolite facies rocks bear sillimanite–muscovite–garnet–plagioclase–quartz–staurolite assemblage, and the higher amphibolite facies rocks bear sillimanite–muscovite–garnet–plagioclase–quartz ± kyanite ± staurolite ± K-feldspar. Cordierite as a sensor of fluid conditions in high‐grade metamorphism and crustal anatexis. The contribution of charnockite magmatism to achieve near-ultrahigh temperatures in the Namaqua–Natal Metamorphic Province, South Africa. Precambrian Research, Elsevier, 2005, 138, pp.183-207. Grujic et al. Metasomatism and the Chemical Transformation of Rock. Geologic setting 2.1 Regional geology The eastern Himalayan syntaxis (EHS) (Fig.1) is the eastern termination of the The northern limit of these occurrences is traditionally marked as Charnockite Line (Fermor, 1936). Regional granulite facies metamorphic terrains occur in all continents and Harley (1989) has listed more than eighty such terrains. mean1 Median ±1σ 1 Archaean gneisses 95 3000– 2500 Dominantly tona-litic to granitic gneisses Early Proterozoic (c. 2.0–1.8 Ga) amphibo-lite- to granulite-facies metamorphism. Golani (1995) divided the HHC or the Thimphu Group into three formations: Sure, Naspe, and Takhsang Formation. The latest, most widespread and intense event at c.1150 Ma gave rise to low-P granulites which record an anticlockwise P-T path and were accompanied by gneissic granite and charnockite. 8.3D). Although this history indicates the overwhelming importance of … Mafics are subordinate in the rock, and muscovite is conspicuous by its presence in the Sure gneiss. Prograde and retrograde reactions, garnet zoning patterns, and accessory phase behaviour in SW Finland migmatites, with implications for geochronology. Protolith lithostratigraphy of the Greater Himalayan Series in Langtang, Nepal: implications for the architecture of the northern Indian margin. The fundamental change in the Earth’s history at the Archaean–Palaeoproterozoic boundary was linked to the transition from Archaean “microplate tectonics” to Palaeoproterozoic “supercontinent tectonics” (or “micro-ocean tectonics” having in mind the limited size of the predominantly Red Sea-type oceans that originated within a partially disrupted supercontinent) (sections 3.4 and 3.6). The element‐partitioning observed in natural rocks suggests that dehydration melting occurs over a temperature interval during which, for most cases, aH2o is driven to lower values. Silica-undersaturated spinel granulites in the Daqingshan complex of the Khondalite Belt, North China Craton: Petrology and quantitative P–T–X constraints. Other workers consider the formation of orthopyroxene to be typical of granulite facies conditions, although this occurs at significantly higher temperatures (100–150 ¯C higher) than does formation of K-feldspar + Al-silicate. Generally, the rocks of the South Delhi Terrane are marked by amphibolite facies metamorphism and multiple stages of folding. The long-term high-temperature history of the central Namaqua Metamorphic Complex: Evidence for a Mesoproterozoic continental back-arc in southern Africa. The creation of the first supercontinent at the end of the Archaean (section 3.2), covering a significant part of the Earth’s surface, must have played an essential role in the reorganisation of the convection cell system in the underlying mantle. In several outcrops especially in the northern part, south of the east–west trending ‘isograd line’, the charnockite occurs either in the form of small lenses or as diffused stains of charnockitic mass described as ‘patchy charnockite’ within the intensely deformed tonalite-trondhjemite-granodiorite gneisses (Fig. The Haast Schist of Jurassic–Cretaceous pumpellyite–actinolite to amphibolite facies overprints the Caples, Bay of Islands, and Rakaia terranes. Also, unlike in the LSL, the compositional zoning in the rim and a homogeneous compositional picture in the core region of garnet, according to Swapp and Hollister (1991), suggest that such P-T conditions were achieved during cooling from a temperature of at least 650°C (probably near 700°C). The mass balance of dehydration melting in typical biotite gneiss and metapelite shows that the proportion of melt in the product assemblage at T± 850°C is relatively small (10–20%), and probably insufficient to mobilize a partially melted rock body. These early Mesoproterozoic tectonic fabrics and metamorphic assemblages were cut at c. 1480–1450 Ma by newly formed and reactivated crustal-scale shear zones (Swain et … With the recognition that much of the intrusion, metamorphism, and deformation in the Buller and Takaka terranes (‘Tuhua Orogen’) occurred during the Cretaceous (of ‘Rangitata’ age), the orogen terminology became obsolete. Tyler, in Encyclopedia of Geology, 2005. Sensitive High Resolution Ion Microprobe (SHRIMP) U–Pb isotope analyses of zircon from a charnockite and a charnockite-hosted leucosome reveal that the felsic magmatism occurred at 2.53 Ga, which was followed by high-grade metamorphism and anatexis at 2.48 Ga (Clark, Collins, Kinny, Timms, & Chetty, 2009). Barrovian Facies Series (medium -P regional) 4. Some Remarks on Melting and Extreme Metamorphism of Crustal Rocks. Outcrop features of granulite-facies migmatites; Vein-like and patchy charnockite in southern India; Metamorphic history of the Namaqualand granulites. The Neoarchean and Paleoproterozoic granulite-gneiss complexes of the northern East European Craton, including their tectonic setting, accompanying igneous and sedimentary rocks, character of metamorphism and deep structure are considered in this paper. The original eclogite-facies mineral assemblage in the mafic rocks has been strongly overprinted by granulite facies metamorphism at 750 C and 0.7–0.8 GPa. Working off-campus? In this paper, we summarize the Proterozoic tectonother- mal evolution of the Broken Hill Block in light of structural, metamorphic and geochronological analysis conducted within a high-temperature shear zone located in the south of the terrane (Forbes et al., 2005, 2007). Both muscovite and quartz are significantly present in the highest grade. Experimental Study of the Melting Reaction and Genetic Mechanism of Mineral Phase Transformation in Granulite Facies Metamorphism. The rocks were subject to deformation at middle to lower crustal levels under granulite and upper amphibolite facies conditions during the Scourian event between c.2,650 Ma to 2,480 Ma. 8.3). Most ruby deposits formed during Ediacaran-Cambrian (ca. Swapp and Holister (1991) studied the amphibolite and sillimanite–granulite facies rocks of Gansser (1983). The third phase of the orogeny took place between 1745 and 1690 Ma and involved deformation, medium-grade metamorphism, and further granite intrusion (Figure 4). Learn more. Spatially‐focussed melt formation in aluminous metapelites from Broken Hill, Australia.