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  • 1.
    Boskabadi, Arman
    et al.
    Univ Texas Dallas, Dept Geosci, ROC 21,800 West Campbell Rd, Richardson, TX 75080 USA.;Stockholm Univ, Dept Geol Sci, Stockholm, Sweden..
    Pitcairn, Iain K.
    Stockholm Univ, Dept Geol Sci, Stockholm, Sweden..
    Broman, Curt
    Stockholm Univ, Dept Geol Sci, Stockholm, Sweden..
    Boyce, Adrian
    Scottish Univ Environm Res Ctr, E Kilbride, Lanark, Scotland..
    Teagle, Damon A. H.
    Univ Southampton, Natl Oceanog Ctr Southampton, Southampton, Hants, England..
    Cooper, Matthew J.
    Univ Southampton, Natl Oceanog Ctr Southampton, Southampton, Hants, England..
    Azer, Mokhles K.
    Natl Res Ctr, Dept Geol, Cairo, Egypt..
    Stern, Robert J.
    Univ Texas Dallas, Dept Geosci, ROC 21,800 West Campbell Rd, Richardson, TX 75080 USA..
    Mohamed, Fathy H.
    Univ Alexandria, Dept Geol, Fac Sci, Alexandria, Egypt..
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics. AGH Univ Sci & Technol, Fac Geol Geophys & Environm Protect, Krakow, Poland..
    Carbonate alteration of ophiolitic rocks in the Arabian-Nubian Shield of Egypt: sources and compositions of the carbonating fluid and implications for the formation of Au deposits2017In: International Geology Review, ISSN 0020-6814, E-ISSN 1938-2839, Vol. 59, no 4, p. 391-419Article, review/survey (Refereed)
    Abstract [en]

    Ultramafic portions of ophiolitic fragments in the Arabian-Nubian Shield (ANS) show pervasive carbonate alteration forming various degrees of carbonated serpentinites and listvenitic rocks. Notwithstanding the extent of the alteration, little is known about the processes that caused it, the source of the CO2 or the conditions of alteration. This study investigates the mineralogy, stable (O, C) and radiogenic (Sr) isotope composition, and geochemistry of suites of variably carbonate altered ultramafics from the Meatiq area of the Central Eastern Desert (CED) of Egypt. The samples investigated include least-altered lizardite (Lz) serpentinites, antigorite (Atg) serpentinites and listvenitic rocks with associated carbonate and quartz veins. The C, O and Sr isotopes of the vein samples cluster between -8.1 parts per thousand and -6.8 parts per thousand for delta C-13, +6.4 parts per thousand and +10.5 parts per thousand for delta O-18, and Sr-87/Sr-86 of 0.7028-0.70344, and plot within the depleted mantle compositional field. The serpentinites isotopic compositions plot on a mixing trend between the depleted-mantle and sedimentary carbonate fields. The carbonate veins contain abundant carbonic (CO2 +/- CH4 +/- N-2) and aqueous-carbonic (H2O-NaCl-CO2 +/- CH4 +/- N-2) low salinity fluid, with trapping conditions of 270-300 degrees C and 0.7-1.1kbar. The serpentinites are enriched in Au, As, S and other fluid-mobile elements relative to primitive and depleted mantle. The extensively carbonated Atg-serpentinites contain significantly lower concentrations of these elements than the Lz-serpentinites suggesting that they were depleted during carbonate alteration. Fluid inclusion and stable isotope compositions of Au deposits in the CED are similar to those from the carbonate veins investigated in the study and we suggest that carbonation of ANS ophiolitic rocks due to influx of mantle-derived CO2-bearing fluids caused break down of Au-bearing minerals such as pentlandite, releasing Au and S to the hydrothermal fluids that later formed the Au-deposits. This is the first time that gold has been observed to be remobilized from rocks during the lizardite-antigorite transition.

  • 2.
    Budzyn, Bartosz
    et al.
    Polish Acad Sci, Res Ctr Krakow ING PAN, Inst Geol Sci, Senacka 1, PL-31002 Krakow, Poland..
    Harlov, Daniel E.
    Geoforschungszentrum Potsdam, D-14473 Potsdam, Germany.;Univ Johannesburg, Dept Geol, POB 524, ZA-2006 Auckland Pk, South Africa..
    Kozub-Budzyn, Gabriela A.
    AGH Univ Sci & Technol, Fac Geol Geophys & Environm Protect, Al A Mickiewicza 30, PL-30059 Krakow, Poland..
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics. AGH Univ Sci & Technol, Fac Geol Geophys & Environm Protect, Al A Mickiewicza 30, PL-30059 Krakow, Poland..
    Experimental constraints on the relative stabilities of the two systems monazite-(Ce) - allanite-(Ce) - fluorapatite and xenotime-(Y) - (Y,HREE)-rich epidote - (Y,HREE)-rich fluorapatite, in high Ca and Na-Ca environments under P-T conditions of 200-1000 MPa and 450-750 A degrees C2017In: Mineralogy and Petrology, ISSN 0930-0708, E-ISSN 1438-1168, Vol. 111, no 2, p. 183-217Article in journal (Refereed)
    Abstract [en]

    The relative stabilities of phases within the two systems monazite-(Ce) - fluorapatite - allanite-(Ce) and xenotime-(Y) - (Y,HREE)-rich fluorapatite - (Y,HREE)-rich epidote have been tested experimentally as a function of pressure and temperature in systems roughly replicating granitic to pelitic composition with high and moderate bulk CaO/Na2O ratios over a wide range of P-T conditions from 200 to 1000 MPa and 450 to 750 A degrees C via four sets of experiments. These included (1) monazite-(Ce), labradorite, sanidine, biotite, muscovite, SiO2, CaF2, and 2 M Ca(OH)(2); (2) monazite-(Ce), albite, sanidine, biotite, muscovite, SiO2, CaF2, Na2Si2O5, and H2O; (3) xenotime-(Y), labradorite, sanidine, biotite, muscovite, garnet, SiO2, CaF2, and 2 M Ca(OH)(2); and (4) xenotime-(Y), albite, sanidine, biotite, muscovite, garnet, SiO2, CaF2, Na2Si2O5, and H2O. Monazite-(Ce) breakdown was documented in experimental sets (1) and (2). In experimental set (1), the Ca high activity (estimated bulk CaO/Na2O ratio of 13.3) promoted the formation of REE-rich epidote, allanite-(Ce), REE-rich fluorapatite, and fluorcalciobritholite at the expense of monazite-(Ce). In contrast, a bulk CaO/Na2O ratio of similar to 1.0 in runs in set (2) prevented the formation of REE-rich epidote and allanite-(Ce). The reacted monazite-(Ce) was partially replaced by REE-rich fluorapatite-fluorcalciobritholite in all runs, REE-rich steacyite in experiments at 450 A degrees C, 200-1000 MPa, and 550 A degrees C, 200-600 MPa, and minor cheralite in runs at 650-750 A degrees C, 200-1000 MPa. The experimental results support previous natural observations and thermodynamic modeling of phase equilibria, which demonstrate that an increased CaO bulk content expands the stability field of allanite-(Ce) relative to monazite-(Ce) at higher temperatures indicating that the relative stabilities of monazite-(Ce) and allanite-(Ce) depend on the bulk CaO/Na2O ratio. The experiments also provide new insights into the re-equilibration of monazite-(Ce) via fluid-aided coupled dissolution-reprecipitation, which affects the Th-U-Pb system in runs at 450 A degrees C, 200-1000 MPa, and 550 A degrees C, 200-600 MPa. A lack of compositional alteration in the Th, U, and Pb in monazite-(Ce) at 550 A degrees C, 800-1000 MPa, and in experiments at 650-750 A degrees C, 200-1000 MPa indicates the limited influence of fluid-mediated alteration on volume diffusion under high P-T conditions. Experimental sets (3) and (4) resulted in xenotime-(Y) breakdown and partial replacement by (Y,REE)-rich fluorapatite to Y-rich fluorcalciobritholite. Additionally, (Y,HREE)-rich epidote formed at the expense of xenotime-(Y) in three runs with 2 M Ca(OH)(2) fluid, at 550 A degrees C, 800 MPa; 650 A degrees C, 800 MPa; and 650 A degrees C, 1000 MPa similar to the experiments involving monazite-(Ce). These results confirm that replacement of xenotime-(Y) by (Y,HREE)-rich epidote is induced by a high Ca bulk content with a high CaO/Na2O ratio. These experiments demonstrate also that the relative stabilities of xenotime-(Y) and (Y,HREE)-rich epidote are strongly controlled by pressure.

  • 3. Ciesielczuk, J.
    et al.
    Kruszewski, L.
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Comparative mineralogical study of thermally-altered coal-dump waste, natural rocks and the products of laboratory heating experiments2015In: International Journal of Coal Geology, ISSN 0166-5162, E-ISSN 1872-7840, Vol. 139, no SI, p. 114-141Article in journal (Refereed)
    Abstract [en]

    Research on rocks formed due to pyrometamorphism of waste in burning coal-mine dumps (BCMD) mainly in the Upper Silesian Coal Basin has enabled identification of a large number of different mineral species. These species are usually well-known minerals, e.g., olivines, plagioclases and clinopyroxenes. However, their crystal chemistry is often unique. Mineralogical- and chemical similarities between the BCMD and non-anthropogenic geological environments are outlined here. To better understand the crystallization processes of the minerals occurring in the BCMD, three types of heating experiments were performed. For these, ten protolith (thermally-unchanged) dump samples, mostly shales and carbonate rocks, were heated alone and mixed together and with a CaF2 flux. Quantitative chemical analyses of the synthesized mixtures have shown that they are mineralogically similar to the rocks found in the BCMD. They are also similar in terms of their crystal chemistry, e.g., synthesized clinopyroxenes are rich in diopside and esseneite components and may capture phosphorus, plagioclase is rich in anorthite and contains iron and magnesium, and wüstite exists as a solid solution with periclase and is doped with calcium and other elements. Highly variable amounts of indialite–ferroindialite were formed in some samples due to solid-phase transformations or melt crystallization, depending on the experimental conditions and the protolith used.

  • 4. Dallmann, W.K.
    et al.
    Elvevold, S.
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Piepjohn, K.
    Tectonics and Tectonothermal events2015In: Geoscience Atlas of Svalbard, Norwegian Polar Institute, Tromso , 2015, p. 175-223Chapter in book (Refereed)
  • 5. Fassmer, Kathrin
    et al.
    Klonowska, Iwona
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Walczak, Katarzyna
    Andersson, Barbro
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Froitzheim, Nikolaus
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Fonseca, Raul
    Munker, Carsten
    Janák, Marian
    Slovak Academy of Sciences.
    Whitehouse, Martin
    Middle Ordovician subduction of continental crust in the Scandinavian Caledonides: an example from Tjeliken, Seve Nappe Complex, Sweden2017In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 172, no 11-12, article id 103Article in journal (Refereed)
    Abstract [en]

    The Seve Nappe Complex of the Scandinavian Caledonides is thought to be derived from the distal passive margin of Baltica which collided with Laurentia in the Scandian Phase of the Caledonian Orogeny at 430-400 Ma. Parts of the Seve Nappe Complex were affected by pre-Scandian high-and ultrahigh-pressure metamorphism, in a tectonic framework that is still unclear, partly due to uncertainties about the exact timing. Previous age determinations yielded between similar to 505 and similar to 446 Ma, with a general trend of older ages in the North (Norrbotten) than in the South (Jamtland). New age determinations were performed on eclogite and garnet-phengite gneiss at Tjeliken in northern Jamtland. Thermodynamic modelling yielded peak metamorphic conditions of 25-27 kbar/680-760 degrees C for the garnet-phengite gneiss, similar to published peak metamorphic conditions of the eclogite (25-26 kbar/650-700 degrees C). Metamorphic rims of zircons from the garnet-phengite gneiss were dated using secondary ion mass spectrometry and yielded a concordia age of 458.9 +/- 2.5 Ma. Lu-Hf garnet-whole rock dating yielded 458 +/- 1.0 Ma for the eclogite. Garnet in the eclogite shows prograde major-element zoning and concentration of Lu in the cores, indicating that this age is related to garnet growth during pressure increase, i.e. subduction. The identical ages from both rock types, coinciding with published Sm-Nd ages from the eclogite, confirm subduction of the Seve Nappe Complex in Northern Jamtland during the Middle Ordovician in a fast subduction-exhumation cycle.

  • 6.
    Gee, David Godfrey
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Per-Gunnar, Andréasson
    Lund University.
    Lorenz, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Frei, Dirk
    Stellenbosch University.
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Detrital zircon signatures of the Baltoscandian margin along the Arctic Circle Caledonides in Sweden: The Sveconorwegian connection2015In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 265, p. 40-56Article in journal (Refereed)
    Abstract [en]

    New evidence is presented here that the Sveconorwegian Orogen continued northwards from type areas in southwestern Scandinavia along the Baltoscandian outer margin into the high Arctic. The Silver Road (Silvervägen) profile through the Scandinavian Caledonides, located in Sweden along the Arctic Circle at 66–67◦ N, provides a full section through the tectonostratigraphy of the Baltoscandian margin from the Autochthon, via the Lower Allochthon to the upperment parts of the Middle Allochthon. Metamorphic grade increases upwards through the nappes, being low greenschist facies at lowest levels and increas- ing to eclogite grade in the highest parts of the Seve Nappe Complex, the latter being related to early Ordovician subduction of the Baltoscandian outermost margin. The sedimentary rocks range in age from Neoproterozoic to Ordovician and provide evidence of the changes of environment from the Baltoscan- dian platform, westwards out over the Cryogenian rifted margin to the continent-ocean transition zone; also the Ordovician foreland basin. Twelve samples of psammites from the different tectonostratigraphic levels have yielded U/Pb detrital zircon age-signatures that reflect the changing character of their pro- venance. Autochthonous sandstones are derived from late Paleoproterozoic (1800–1950 Ma) crystalline rocks in the vicinity to the east of the thrust front. Ediacaran-early Cambrian quartzites of the Lower Allochthon also yield mainly late Paleoproterozoic zircon signatures, but with subordinate Mesopro- terozoic and late Archaean populations, whilst mid Ordovician, W-derived foreland basin turbidites are dominated by Sveconorwegian (950–1100 Ma) signatures, with subordinate older Mesoproterozoic to latest Paleoproterozoic populations. All samples from the lower parts of the Middle Allochthon (lacking dolerite dykes) have signatures that are dominated by latest Paleoproterozoic and early Mesoproterozoic ages, with subordinate populations down to Sveconorwegian ages; the latter dominate the overlying Särv nappes and also the Seve Nappe Complex, where c. 945 Ma rhyodacites have been previously reported. This evidence of Sveconorwegian source rocks in the hinterland, taken together with previously pub- lished detrital zircon data farther south and north of the Arctic Circle, clearly favours the interpretation that the Sveconorwegian Orogen, during the Neoproterozoic, extended along the entire Baltoscandian outer margin into the high Arctic.

  • 7.
    Klonowska, Iwona
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Janák, Marian
    Slovak Academy of Sciences.
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences. AGH - University of Science and Technology, Department of Mineralogy, Petrography and Geochemistry.
    Petrik, Igor
    Slovak Academy of Sciences.
    Froitzheim, Nikolaus
    University of Bonn.
    Gee, David
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Sasinkova, Vlasta
    Slovak Academy of Sciences.
    Microdiamond on Åreskutan confirms regional UHP metamorphism in the Seve Nappe Complex of the Scandinavian Caledonides2017In: Journal of Metamorphic Geology, ISSN 0263-4929, E-ISSN 1525-1314, Vol. 35, p. 541-564Article in journal (Refereed)
    Abstract [en]

    Metamorphic diamond in crustal rocks provides important information on the deep subduction of continental crust. Here, we present a new occurrence of diamond within the Seve Nappe Complex (SNC) of the Scandinavian Caledonides, on angstrom reskutan in Jamtland County, Sweden. Microdiamond is found insitu as single and composite (diamond+carbonate) inclusions within garnet, in kyanite-bearing paragneisses. The rocks preserve the primary peak pressure assemblage of Ca,Mg-rich garnet+phengite+kyanite+rutile, with polycrystalline quartz surrounded by radial cracks indicating breakdown of coesite. Calculated P-T conditions for this stage are 830-840 degrees C and 4.1-4.2GPa, in the diamond stability field. The ultrahigh-pressure (UHP) assemblage has been variably overprinted under granulite facies conditions of 850-860 degrees C and 1.0-1.1GPa, leading to formation of Ca,Mg-poor garnet+biotite+plagioclase+K-feldspar+sillimanite+ilmenite+quartz. This overprint was the result of nearly isothermal decompression, which is corroborated by Ti-in-quartz thermometry. Chemical Th-U-Pb dating of monazite yields ages between 445 and 435Ma, which are interpreted to record post-UHP exhumation of the diamond-bearing rocks. The new discovery of microdiamond on angstrom reskutan, together with other evidence of ultrahigh-pressure metamorphism (UHPM) within gneisses, eclogites and peridotites elsewhere in the SNC, provide compelling arguments for regional (at least 200km along strike of the unit) UHPM of substantial parts of this far-travelled allochthon. The occurrence of UHPM in both rheologically weak (gneisses) and strong lithologies (eclogites, peridotites) speaks against the presence of large tectonic overpressure during metamorphism.

  • 8.
    Majka, Jaroslaw
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics. AGH Univ Sci & Technol, Fac Geol Geophys & Environm Protect, Al Mickiewicza 30, PL-30059 Krakow, Poland..
    Mazur, Stanislaw
    Polish Acad Sci, Inst Geol Sci, Ul Senacka 1, PL-31002 Krakow, Poland..
    Kosminska, Karolina
    AGH Univ Sci & Technol, Fac Geol Geophys & Environm Protect, Al Mickiewicza 30, PL-30059 Krakow, Poland..
    Dudek, Krzysztof
    AGH Univ Sci & Technol, Fac Geol Geophys & Environm Protect, Al Mickiewicza 30, PL-30059 Krakow, Poland..
    Klonowska, Iwona
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Pressure-temperature estimates of the blueschists from the Kopina Mt., northern Bohemian Massif, Poland - constraints on subduction of the Saxothuringian continental margin2016In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 28, no 6, p. 1047-1057Article in journal (Refereed)
    Abstract [en]

    The blueschist occurrence at the Kopina Mt. is situated at the eastern margin of the Karkonosze Izera Massif in the West Sudetes of the northern Bohemian Massif. Metabasic rocks with continental crust affinity occur as lenses within the prevailing metasediments. The metabasites consist mainly of garnet, blue amphibole, epidote, chlorite-I, titanite, hematite and quartz forming the high-pressure assemblage. Synkinematic garnet exhibits prograde zoning, a feature allowing for assessment of the prograde course of the pressure temperature (P-T) path. Phase equilibrium modelling has been used to estimate prograde and peak metamorphic conditions. Based on the P-T pseudosections, calculated in the system Na2O-CaO-K2O-FeO-MgO-MnO- Al2O3-SiO2-H2O-TiO2-O-2 (NCKFMMnASHTO), the garnet + glaucophane + epidote + chlorite + white mica(?) + Fe oxide + quartz titanite assemblage was formed between 12-15 kbar and 480-520 degrees C. These results are based on garnet and Na-amphibole compositional isopleths. Garnet shows a prograde zoning expressed by the rapid rim-ward decrease of spessartine, moderate increase of almandine and as light increase of other components. It is inferred here that white mica must have decomposed to secondary albite chlorite-II K-feldspar. The obtained results point to the formation of the Kopina blueschists along a low-temperature P-T gradient of 8-10 degrees C/km, typical of rocks from a subduction exhumation channel. We postulate that the Kopina blueschists were formed in a subduction system developed along the eastern termination of the Saxothuringian Ocean and operating beneath the Tepla Barrandian upper plate. When combined with previous data on continental crust affinity for the protolith, our results demonstrate a derivation of the Kopina blueschists from subducted part of the Saxothuringian margin.

  • 9.
    Woodard, Jeremy
    et al.
    Univ KwaZulu Natal, Sch Agr, Geol Sci, Earth & Environm Sci, Private Bag X 54001, Durban, South Africa..
    Tuisku, Pekka
    Univ Oulu, Dept Geosciences, Oulu 90014, Finland..
    Kaerki, Aulis
    Univ Oulu, Dept Geosciences, Oulu 90014, Finland..
    Lahaye, Yann
    Geol Survey Finland, POB 96, Espoo 02151, Finland..
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics. AGH Univ Sci & Technol, Fac Geol, Geophys & Environm Protect, Mickiewicza 30, PL-30059 Krakow, Poland..
    Huhma, Hannu
    Geol Survey Finland, POB 96, Espoo 02151, Finland..
    Whitehouse, Martin J.
    Swedish Museum Nat Hist, Lab Isotope Geol, Box 50007, S-10405 Stockholm, Sweden..
    Zircon and monazite geochronology of deformation in the Pielavesi Shear Zone, Finland: multistage evolution of the Archaean-Proterozoic boundary in the Fennoscandian Shield2017In: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 174, no 2, p. 255-267Article in journal (Refereed)
    Abstract [en]

    The Raahe-Ladoga Shear Complex is a major crustal structure representing the Archaean-Palaeoproterozoic boundary in the Fennoscandian Shield. The complex developed during the Svecofennian Orogeny (c. 1.9 - 1.8 Ga) beginning with regional thrust tectonic phases D-1 and D-2, followed by large-scale shearing events D-3 and D-4. The Pielavesi Shear Zone is a vertical north-south-trending shear zone within the Raahe-Ladoga Shear Complex formed during regional D-3 shearing and later reactivated during the regional D-4 phase. Three north-south-trending elongate granitoid intrusions were selected as representative of silicic melts that intruded the transtensional Pielavesi Shear Zone during the regional D-3 phase. The oriented magmatic fabric of the granitoids indicates that they intruded coeval to the deformation event. The zircon U-(Th)-Pb secondary ionization mass spectrometry (SIMS) ages of these intrusions (1888 +/- 4, 1884 +/- 6 and 1883 +/- 5 Ma) overlap within error and provide a direct age for the regional D-3 deformation. epsilon(Hf(T)) (-1.1 to + 3.4) and epsilon(Nd(T)) (-1.2 to + 0.4) values from these granitoids are both consistent with a predominantly juvenile source affected by a minor Archaean component. U-(Th)-Pb SIMS analyses of metamorphic monazite formed within a crosscutting blastomylonite provide an age for the regional D-4 phase and associated fluid activity of 1793 +/- 3 Ma.

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