Articles | Volume 36, issue 2
https://doi.org/10.5194/ejm-36-345-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/ejm-36-345-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
27 Mar 2024
Research article |
| 27 Mar 2024
| 27 Mar 2024
Metamorphic evolution of sillimanite gneiss in the high-pressure terrane of the Western Gneiss Region (Norway)
Geological Survey of Norway, P.O. Box 6315 Torgarden, 7491 Trondheim, Norway
Johannes Jakob
Geological Survey of Norway, P.O. Box 6315 Torgarden, 7491 Trondheim, Norway
Related authors
Synnøve Elvevold, Joachim Jacobs, Leif-Erik Rydland Pedersen, Øyvind Sunde, Ane K. Engvik, and Per Inge Myhre
Eur. J. Mineral., 35, 969–985, https://doi.org/10.5194/ejm-35-969-2023, https://doi.org/10.5194/ejm-35-969-2023, 2023
Short summary
Short summary
The present study of mafic rocks from Jutulsessen, Gjelsvikfjella, extends the presence of high-pressure rocks in the Maud Belt in Dronning Maud Land, Antarctica. The physical conditions necessary for the development of these rocks were attained during continent–continent collision along the East African–Antarctic Orogen. The new data in this study largely confirm the geodynamic implication outlined by others for the region.
Synnøve Elvevold, Joachim Jacobs, Leif-Erik Rydland Pedersen, Øyvind Sunde, Ane K. Engvik, and Per Inge Myhre
Eur. J. Mineral., 35, 969–985, https://doi.org/10.5194/ejm-35-969-2023, https://doi.org/10.5194/ejm-35-969-2023, 2023
Short summary
Short summary
The present study of mafic rocks from Jutulsessen, Gjelsvikfjella, extends the presence of high-pressure rocks in the Maud Belt in Dronning Maud Land, Antarctica. The physical conditions necessary for the development of these rocks were attained during continent–continent collision along the East African–Antarctic Orogen. The new data in this study largely confirm the geodynamic implication outlined by others for the region.
Related subject area
Metamorphic petrology
Sedimentary protolith and high-P metamorphism of oxidized manganiferous quartzite from the Lanterman Range, northern Victoria Land, Antarctica
Halogen-bearing metasomatizing melt preserved in high-pressure (HP) eclogites of Pfaffenberg, Bohemian Massif
Île Dumet (Armorican Massif, France) and its glaucophane eclogites: the little sister of Île de Groix
Retrogression of ultrahigh-pressure eclogite, Western Gneiss Region, Norway
Electron backscatter diffraction analysis combined with NanoSIMS U–Pb isotope data reveal intra-grain plastic deformation in zircon and its effects on U–Pb age: examples from Himalayan eclogites, Pakistan
H2O and Cl in deep crustal melts: the message of melt inclusions in metamorphic rocks
Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chlorite
Partial melting of amphibole–clinozoisite eclogite at the pressure maximum (eclogite type locality, Eastern Alps, Austria)
Petrological study of an eclogite-facies metagranite from the Champtoceaux Complex (La Picherais, Armorican Massif, France)
Corundum-bearing and spinel-bearing symplectites in ultrahigh-pressure eclogites record high-temperature overprint and partial melting during slab exhumation
Some thoughts about eclogites and related rocks
Metamorphic P–T paths of Archean granulite facies metasedimentary lithologies from the eastern Beartooth Mountains of the northern Wyoming Province, Montana, USA: constraints from quartz-in-garnet (QuiG) Raman elastic barometry, geothermobarometry, and thermodynamic modeling
Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland
Equilibrium and kinetic approaches to understand the occurrence of the uncommon chloritoid + biotite assemblage
Geochemistry and paleogeographic implications of Permo-Triassic metasedimentary cover from the Tauern Window (Eastern Alps)
Reaction progress of clay minerals and carbonaceous matter in a contact metamorphic aureole (Torres del Paine intrusion, Chile)
Partial melting of zoisite eclogite from the Sanddal area, North-East Greenland Caledonides
Taehwan Kim, Yoonsup Kim, Simone Tumiati, Daeyeong Kim, Keewook Yi, and Mi Jung Lee
Eur. J. Mineral., 36, 323–343, https://doi.org/10.5194/ejm-36-323-2024, https://doi.org/10.5194/ejm-36-323-2024, 2024
Short summary
Short summary
The manganese-rich siliceous metasediment in the Antarctic Ross orogen most likely originated from Mn-nodule-bearing chert deposited not earlier than ca. 546 Ma. Subduction-related metamorphism resulted in the production of highly oxidized assemblages involving Mn3+ and rare-earth-element-zoned epidote-group mineral and Mn2+-rich garnet. A reduced environment was responsible for the Mn olivine-bearing assemblages from silica-deficient composition.
Alessia Borghini, Silvio Ferrero, Patrick J. O'Brien, Bernd Wunder, Peter Tollan, Jarosław Majka, Rico Fuchs, and Kerstin Gresky
Eur. J. Mineral., 36, 279–300, https://doi.org/10.5194/ejm-36-279-2024, https://doi.org/10.5194/ejm-36-279-2024, 2024
Short summary
Short summary
We studied primary granitic and halogen-rich melt inclusions trapped in mantle rocks in the Bohemian Massif (Germany) in order to retrieve important information about the nature of the melt and the source rock. The melt was produced by the partial melting of metasediments during the deepest stages of subduction and interacted with the mantle. This work is an excellent example of transfer of crustal material, volatiles in particular, in the mantle during the subduction of the continental crust.
Gaston Godard, David C. Smith, Damien Jaujard, and Sidali Doukkari
Eur. J. Mineral., 36, 99–122, https://doi.org/10.5194/ejm-36-99-2024, https://doi.org/10.5194/ejm-36-99-2024, 2024
Short summary
Short summary
Petrological and mineralogical studies of mica schists, orthogneisses and glaucophane eclogites from Dumet Island (Armorican Massif, NW France) indicate that this occurrence, which has undergone high-pressure metamorphism up to 16 kbar and 620 °C, is similar to that of Groix Island. There are about 10 similar occurrences within the Ibero-Armorican Arc, forming a discontinuous high-pressure belt, but most of them have remained unnoticed due to a high degree of retrogression.
Dirk Spengler, Adam Włodek, Xin Zhong, Anselm Loges, and Simon J. Cuthbert
Eur. J. Mineral., 35, 1125–1147, https://doi.org/10.5194/ejm-35-1125-2023, https://doi.org/10.5194/ejm-35-1125-2023, 2023
Short summary
Short summary
Rock lenses from the diamond stability field (>120 km depth) within ordinary gneiss are enigmatic. Even more when these lenses form an alternating exposure pattern with ordinary lenses. We studied 10 lenses from W Norway and found that many of them have a hidden history. Tiny needles of quartz enclosed in old pyroxene cores are evidence for a rock origin at great depth. These needles survived the rocks' passage to the surface that variably obscured the mineral chemistry – the rocks' memory.
Hafiz U. Rehman, Takanori Kagoshima, Naoto Takahata, Yuji Sano, Fabrice Barou, David Mainprice, and Hiroshi Yamamoto
Eur. J. Mineral., 35, 1079–1090, https://doi.org/10.5194/ejm-35-1079-2023, https://doi.org/10.5194/ejm-35-1079-2023, 2023
Short summary
Short summary
Zircon preserves geologic rock history. Electron backscatter diffraction (EBSD) analysis is useful to visualize deformed domains in zircons. Zircons from the Himalayan high-pressure eclogites were analzyed for EBSD to identify intra-grain plastic deformation. The U–Pb isotope age dating, using Nano-SIMS, showed that plastic deformation likely affects the geochronological records. For geologically meaningful results, it is necessary to identify undisturbed domains in zircon via EBSD.
Silvio Ferrero, Alessia Borghini, Laurent Remusat, Gautier Nicoli, Bernd Wunder, and Roberto Braga
Eur. J. Mineral., 35, 1031–1049, https://doi.org/10.5194/ejm-35-1031-2023, https://doi.org/10.5194/ejm-35-1031-2023, 2023
Short summary
Short summary
Garnet often entraps small droplets of deep melts generated during mountain building processes. Using high-resolution techniques, we studied these droplets in order to provide hard numbers for the quantification of volatile budgets during crustal evolution, show how even melts formed at >1000°C contain water, and clarify how water behaves during metamorphism and melting at the microscale. Moreover, we provide the very first data on chlorine in natural melts from crustal reworking.
Benoît Dubacq, Guillaume Bonnet, Manon Warembourg, and Benoît Baptiste
Eur. J. Mineral., 35, 831–844, https://doi.org/10.5194/ejm-35-831-2023, https://doi.org/10.5194/ejm-35-831-2023, 2023
Short summary
Short summary
Minerals in a vein network from the Aravis limestone (Haute-Savoie, France) include carbonates, quartz, fluorite and phyllosilicates, crystallized at around 7 km depth and 190 °C. The mineralogy has been studied with emphasis on the chlorite types: chamosite (iron-rich), cookeite (lithium-rich) and sudoite. The presence of the three chlorite types sheds light on their phase diagrams, and observed cationic substitutions confirm the need for more systematic measurement of lithium in chlorite.
Simon Schorn, Anna Rogowitz, and Christoph A. Hauzenberger
Eur. J. Mineral., 35, 715–735, https://doi.org/10.5194/ejm-35-715-2023, https://doi.org/10.5194/ejm-35-715-2023, 2023
Short summary
Short summary
We investigate rocks called eclogite, which are related to subduction and the collision of continents. Our samples show evidence of limited melting at high pressure corresponding to about 70 km depth, which may play an important role in the exhumation of these rocks and the differentiation of the crust. However, due to their composition and metamorphic evolution, melt production is limited, suggesting that similar rocks are unlikely to contribute strongly to subduction-related magmatism.
Thomas Gyomlai, Philippe Yamato, and Gaston Godard
Eur. J. Mineral., 35, 589–611, https://doi.org/10.5194/ejm-35-589-2023, https://doi.org/10.5194/ejm-35-589-2023, 2023
Short summary
Short summary
The La Picherais metagranite is a key example of undeformed high-pressure quartzofeldspathic rock from the Armorican Massif. Through petrological observations and thermodynamic modelling, this study determines that the metagranite was pressured above 1.7 GPa and the associated mafic lenses at ~ 2.1 GPa. This metagranite provides an opportunity to study the degree of transformation of quartzofeldspathic rocks at high pressure, which may have a significant impact on the dynamics of subduction.
Pan Tang and Shun Guo
Eur. J. Mineral., 35, 569–588, https://doi.org/10.5194/ejm-35-569-2023, https://doi.org/10.5194/ejm-35-569-2023, 2023
Short summary
Short summary
In this study, unusual corundum- and spinel-bearing symplectites after muscovite were found in ultrahigh-pressure eclogites from the Dabie terrane, China. The results indicate that these symplectites formed by the low-pressure partial melting of muscovite during slab exhumation. We stress that the occurrence of corundum- and spinel-bearing symplectites after muscovite in eclogites provides important implications for fluid and melt actions in exhumed slabs.
Michael Brown
Eur. J. Mineral., 35, 523–547, https://doi.org/10.5194/ejm-35-523-2023, https://doi.org/10.5194/ejm-35-523-2023, 2023
Short summary
Short summary
The past 40 years have been a golden age for eclogite studies, supported by an ever wider range of instrumentation and enhanced computational capabilities, linked with ongoing developments in the determination of the temperatures and pressures of metamorphism and the age of these rocks. These data have been used to investigate the spatiotemporal distribution of metamorphism and secular change but not without controversy in relation to the emergence of plate tectonics on Earth.
Larry Tuttle and Darrell J. Henry
Eur. J. Mineral., 35, 499–522, https://doi.org/10.5194/ejm-35-499-2023, https://doi.org/10.5194/ejm-35-499-2023, 2023
Short summary
Short summary
Quartz inclusions in garnet are used to constrain the metamorphic pressure–temperature history of multiple ~2.8 Ga metasedimentary rocks from Montana, USA. Inclusion studies along with mineral and whole rock chemistry suggests that the rocks of interest experienced a clockwise metamorphic P–T history that included isobaric heating to peak metamorphic temperatures once inclusions were entrapped. These findings place fundamental constraints on the P–T evolution of this important geologic setting.
Jan Schönig, Carsten Benner, Guido Meinhold, Hilmar von Eynatten, and N. Keno Lünsdorf
Eur. J. Mineral., 35, 479–498, https://doi.org/10.5194/ejm-35-479-2023, https://doi.org/10.5194/ejm-35-479-2023, 2023
Short summary
Short summary
When and how modern-style plate tectonics initiated is a matter of debate. Although the earliest unequivocal evidence for ultrahigh-pressure metamorphism is Neoproterozoic, similar processes have been proposed for Paleoproterozoic rocks of western Greenland. We intensely screened the area by studying detrital heavy minerals, garnet chemistry, and mineral inclusion assemblages in garnet. Our results raise considerable doubts on the existence of Paleoproterozoic ultrahigh-pressure rocks.
Sara Nerone, Chiara Groppo, and Franco Rolfo
Eur. J. Mineral., 35, 305–320, https://doi.org/10.5194/ejm-35-305-2023, https://doi.org/10.5194/ejm-35-305-2023, 2023
Short summary
Short summary
The coexistence of chloritoid and biotite in medium-pressure Barrovian terranes is uncommon, with chloritoid usually occurring at lower temperatures than biotite. A petrologic approach using equilibrium thermodynamic modelling points out how metapelites can attain H2O-undersaturated conditions even at medium pressure and amphibolite-facies conditions and consequently can be affected by kinetic barriers, which need to be taken into account.
Gerhard Franz, Martin Kutzschbach, Eleanor J. Berryman, Anette Meixner, Anselm Loges, and Dina Schultze
Eur. J. Mineral., 33, 401–423, https://doi.org/10.5194/ejm-33-401-2021, https://doi.org/10.5194/ejm-33-401-2021, 2021
Short summary
Short summary
Metamorphic rocks contain information about their original rocks and thus provide insight into the earlier stages of a region of interest. Here, we used the whole-rock chemical composition and stable boron isotopes of a suite of rocks from the Alps (Italy–Austria), which were deposited in a restricted intramontane basin before the Alpine orogeny. It is possible to reconstruct the depositional conditions for these sediments, which are now common metamorphic rocks such as schists and gneisses.
Annette Süssenberger, Susanne Theodora Schmidt, Florian H. Schmidt, and Manuel F. G. Weinkauf
Eur. J. Mineral., 32, 653–671, https://doi.org/10.5194/ejm-32-653-2020, https://doi.org/10.5194/ejm-32-653-2020, 2020
Wentao Cao, Jane A. Gilotti, and Hans-Joachim Massonne
Eur. J. Mineral., 32, 405–425, https://doi.org/10.5194/ejm-32-405-2020, https://doi.org/10.5194/ejm-32-405-2020, 2020
Short summary
Short summary
Zoisite eclogites from the Sanddal area, North-East Greenland, contain numerous textures, such as cusps and neoblasts, which are interpreted as melt-related textures. Mineral chemistry and thermodynamic modeling demonstrate that they were partially melted through the breakdown of hydrous minerals, phengite, paragonite and zoisite. Pressure–temperature phase diagrams show that the eclogites reached a maximum depth of ∼70 km and were partially melted near that depth and during exhumation.
Cited articles
Andersen, T. B., Jamtveit, B., Dewey, J. F., and Swensson, E.: Subduction and eduction of continental crust: major mechanisms during continent-continent collision and orogenic extensional collapse, a model based on the south Caledonides, Terra Nova, 3, 303–310, 1991.
Austrheim, H., Corfu, F., Bryhni, I., and Andersen, T. B.: The Proterozoic Hustad igneous complex; a low strain enclave with a key to the history of the Western Gneiss Region of Norway, Precambrian Res., 120, 149–175, 2003.
Barrow, G.: On the geology of lower Dee-side and the southern Highland Border, P. Geologist. Assoc., 23, 274–290, 1912.
Boullier, A.-M. and Bouchez, J.-L.: Le quartz en rubans dans les mylonites, B. Soc. Géol. Fr., 7, 253–262, 1978.
Butler, J. P., Jamieson, R. A., Steenkamp, H. M., and Robinson, P.: Discovery of coesite-eclogite from Nordøyane UHP domain, Western Gneiss Region, Norway: field relations, metamorphic history, and tectonic significance, J. Metamorph. Geol., 31, 147–163, 2013.
Caddick, M. J., Konopasek, J., and Thompson, A. B.: Preservation of Garnet Growth Zoning and the Duration of Prograde Metamorphism, J. Petrol., 51, 2327–2347, 2010.
deCapitani, C. and Petrakakis, K.: The computation of equilibrium assemblage diagrams with Theriak/Domino software, Am. Mineral., 95, 1006–1016, 2010.
Chen, J., Jin, Z., Liu, W., Wang, Y., and Jufeng, Z.: Rheology of dry K-feldspar aggregate at high temperature and high pressure: An experimental study, Tectonophysics, 817, 229072, https://doi.org/10.1016/j.tecto.2021.229072, 2021.
DesOrmeau, J. W., Gordon, S. M., Kylander-Clark, A. R. C., Hacker, B. R., Bowring, S. A., Schoene, B., and Samperton, K. M.: Insights into (U)HP metamorphism of the Western Gneiss Region, Norway: A high-spatial resolution and high-precision zircon study, Chem. Geol., 414, 138–155, 2015.
Dobrzhinetskaya, L. F., Eide, E. A., Larsen, R. B., Sturt, B. A., Trønnes, R., Smith, D. C., Taylor, W. R., and Posukhova, T. V.: Microdiamond in high-grade metamorphic rocks of the Western Gneiss Region, Norway, Geology, 7, 597–600, 1995.
Engvik, A. K. and Andersen, T. B.: Evolution of Caledonian deformation fabrics under eclogite and amphibolite facies at Vårdalsneset, Western Gneiss Region, Norway, J. Metamorph. Geol., 18, 241–257, 2000.
Engvik, A. K., Austrheim, H., and Andersen, T. B.: Structural, mineralogical and petrophysical effects on deep crustal rocks of fluid-limited polymetamorphism, Western Gneiss Region, Norway, J. Geol. Soc. Lond., 157, 121–134, 2000.
Engvik, A. K., Willemoes-Wissing, B., and Lutro, O.: High-temperature, decompressional equilibration of the eclogite facies orogenic root, Western Gneiss Region, Norway, J. Metamorph. Geol., 36, 529–545, 2018.
Engvik, A. K., Mertens, C., and Trepmann, C. A.: Episodic deformation and reactions in mylonitic high-grade metamorphic granulites from Dronning Maud Land, Antarctica, J. Struct. Geol., 141, 104196, https://doi.org/10.1016/j.jsg.2020.104196, 2020.
Faryad, S. W. and Ježek, J.: Compositional zoning in garnet and its modification by diffusion during pressure and temperature changes in metamorphic rocks; an approach and software, Lithos, 332–333, 287–295, 2019.
Gaidies, F., de Capitani, C., and Abart, R.: THERIA_G: a software program to numerically model prograde garnet growth, Contrib. Mineral. Petr., 155, 657–671, 2008.
Gillen, C.: Metamorphic Geology, George Allen & Unwin, London, 1982.
Griffin, W. L., Austrheim, H., Braasted, K., Bryhni, I., Krill, A. G., Krogh, E. J., Mørk, M. B. E., Quale, H., and Tørudbakken, B.: High-pressure metamorphism in the Scandinavian Caledonides, in: The Caledonide Orogen – Scandinavia and Related Areas, edited by: Gee, D. G., and Sturt, B. A., John Wiley & Sons Ltd, Chichester, 783–802, 1985.
Hacker, B. R.: Ascent of the ultrahigh-pressure Western Gneiss Region, Norway, Geol. Soc. Am. Spec. Pap., 419, 171–184, 2007.
Hacker, B. R., Andersen, T. B., Kylander-Clark, A. R. C., Johnston, S., Peterman, E., Walsh, E. O., and Young, D.: High-temperature deformation during continental-margin subduction and exhumation: The ultrahigh-pressure Western Gneiss Region of Norway, Tectonphysics, 480, 149–171, 2010.
Hippertt, J., Rocha, A., Lana, C., Egydio-Silva, M., and Takeshita, T.: Quartz plastic segregation and ribbon development in high-grade striped gneisses, J. Struct. Geol., 23, 67–80, 2001.
Holland, T. J. B. and Powell, R.: An improved and extended internally consistent thermodynamic dataset for phases of petrological interest, involving a new equation of state for solids, J. Metamorph. Geol., 29, 333–383, 2011.
Holmberg, J., Bukala, M., Jeanneret, P., Klonowska, I., and Majka, J.: Decompressional equilibration of the Misund granulite from Otrøy, Western Gneiss Region, Norway, Geol. Carpath., 70, 471–482, 2019.
Krogh, E. J.: Evidence for a Precambrian continent-continent collision in western Norway, Nature, 267, 17–19, 1977.
Krogh, T. E., Kamo, S. L., Robinson, P., Terry, M. P., and Kwok, K.: U-Pb zircon geochronology of eclogites from the Scandian Orogen, Northern Western Gneiss Region, Norway: 14–20 million years between eclogite crystallization and return to amphibolite facies conditions, Can. J. Earth Sci., 48, 441–472, 2011.
Larsen, R. B., Eide, E. A., and Burke, E. A. J.: Evolution of metamorphic volatiles during exhumation of microdiamond-bearing granulites in the Western Gneiss Region, Norway, Contrib. Mineral. Petr., 133, 106–121, 1998.
March, S., Hand, M., Tamblyn, R., Carvalho, B. B., and Clark, C.: A diachronous record of metamorphism in metapelites of the Western Gneiss Region, Norway, J. Metamorph. Geol., 40, 1121–158, 2022.
Mandal, N., Fujino, K., and Samanta, S. K.: Development of quartz ribbons in quartzofeldspathic granulites, P. Indian A.S.-Earth, 106, 225–236, 1997.
McLelland, J., Morrison, J., Selleck, B., Cunningham, B., Olson, C., and Schmidt, K.: Hydrothermal alteration of late- to post-tectonic Lyon Mountain granitic Gneiss, Adirondack Mountains, New York: Origin of quartz-sillimanite segregations, quartz-albite lithologies, and associated Kiruna-type low-Ti Fe-oxide deposits, J. Metamorph. Geol., 20, 175–190, 2002.
Martin, C., Duchene, S., Luais, B., Goncalves, P., Deloule, E., and Fournier, C.: Behavior of trace elements in relation to Lu-Hf and Sm-Nd geochronometers during metamorphic dehydration-hydration in the HP domain of Vårdalsneset, Western Gneiss Region, Norway, Contrib. Mineral. Petr., 159, 437–458, 2010.
Munz, I. A., Wayne, D., and Austrheim, H.: Retrograde fluid infiltration in the high-grade Modum Complex, South Norway; evidence for age, source and REE mobility, Contrib. Mineral. Petr., 116, 32–46, 1994.
Nabelek, P. I.: Quartz-sillimanite leucosomes in high grade schist, Black Hills, South Dakota: a perspective on the mobility of aluminium in high grade metamorphic rocks, Geology, 25, 995–998, 1997.
Oppikofer, T., Bunkholt, H., Ganerød, G. V., and Engvik, A. K.: Mannen unstable rock slope (Møre and Romsdal): Geological and engineering geological logging of drill core KH-02-11 & grain size distribution and XRD analyses of fine-grained breccias, Norges geologiske undersøkelse, NGU Report 2012.036, 2012.
Pouchou, J. P. and Pichoir, F.: Cameca PAP program, Rech. Aerospatiale, 3, 167–192, 1984.
Roberts, D.: The Scandinavian Caledonides: event chronology, palaeogeographic settings and likely modern analogues, Tectonophysics, 365, 283–299, 2003.
Røhr, T. S., Bingen, B., Robinson, P., and Reddy, S. M.: Geochronology of Palaeoproterozoic augen gneisses in the Western Gneiss Region, Norway: evidences for Sveconorwegian zircon neocrystallization and Caledonian zircon deformation, J. Geol., 121, 105–128, 2012.
Saintot, A., Elvebakk, H., Ganerød, G. V., Oppikofer, T., and Farsund, T.: Mannen unstable rock-slope (Romsdal, Møre & Romsdal County): Logging of drill hole and core KH-01-10 coupled to the geomorphologic interpretation of 1 m resolution digital elevation model and terrestrial lidar scan displacement analysis, Norges geologiske undersøkelse, NGU Report 2011.026, 2011.
Smith, D. C.: Coesite in clinopyroxene in the Caledonides and its implications for geodynamics, Nature, 310, 641–644, 1984.
Spry, P. G., Mcfadden, S., Teale, G. S., Alers, B., Shalloe, J. M., and Glenn, J. M.: Nodular sillimanite rocks as field indicators to metamorphosed massive sulphide deposits, Ore Geol. Rev., 141, 104632, https://doi.org/10.1016/j.oregeorev.2021.104632, 2022.
Terry, M. P., Robinson, P., Hamilton, M. A., and Jercinovic, M. J.: Monazite geochronology of UHP and HP metamorphism, deformation, and exhumation, Nordøyane, Western Gneiss Region, Norway, Am. Mineral., 85, 1651–1664, 2000.
Thinkham, D. K.: Dr. Douglas K. Tinkham, Overview, https://dtinkham.net last access: 19 June 2023.
Tucker, R. D., Råheim, A., Krogh, T. E., and Corfu, F.: Uranium-lead zircon and titanite ages from the northern portion of the Western Gneiss Region, south-central Norway, Earth Planet. Sc. Lett., 81, 203–211, 1987.
Tucker, R. D., Robinson, P., Solli, A., Gee, D. G., Thorsnes, T., Krogh, T. E., Nordgulen, Ø., and Bickford, M. E.: Thrusting and extension in the Scandinavian hinterland, Norway: New U-Pb ages and tectonostratigraphic evidences, Am. J. Sci., 304, 477–532, 2004.
Tveten, E., Lutro, O., and Thorsnes, T.: Geologisk kart over Noreg: berggrunnskart Ålesund: M 1 : 250.000, Norges geologiske undersøkelse, 1998.
Vernon, R. H.: Formation of late sillimanite by hydrogen metasomatism (base leaching) in some high-grade gneisses, Lithos, 12, 143–145, 1979.
Vernon, R. H.: K-feldspar augen in felsic gneisses and mylonites – deformed phenocrysts or porphyroblasts?, GFF, 112, 157–167, 1990.
Vrijmoed, J. C., Van Roermund, H. L. M., and Davies, G.: Evidence for diamond-grade ultra-high pressure metamorphism and fluid interaction in the Svartberget Fe-Ti garnet periodotite-websterite body, Western Gneiss Region, Norway, Miner. Petrol., 88, 381–405, 2006.
Wain, A. L.: New evidence for coesite in eclogite and gneisses: Defining an ultrahigh-pressure province in the Western Gneiss region of Norway, Geology, 25, 927–930, 1997.
Walsh, E. O. and Hacker, B. R.: The fate of subducted continental margins: Two-stage exhumation of the high-pressure to ultrahigh-pressure Western Gneiss Region, Norway, J. Metamorph. Geol., 22, 671–687, 2004.
Walsh, E. O., Hacker, B. R., Gans, P. R., Grove, M., and Gehrels, G.: Protolith ages and exhumation histories of (ultra)high-pressure rocks across the Western Gneiss Region, Norway, Geol. Soc. Am. Bull., 119, 289–301, 2007.
Walsh, E. O., Hacker, B. R., Gans, P. B., Wong, M. S., and Andersen, T. B.: Crustal exhumation of the Western Gneiss Region UHP terrane, Norway:
Whitney, D. L. and Evans, B. W.: Abbreviations for names of rock-forming minerals, Am. Mineral., 95, 185–187, 2010.
Short summary
The paper documents sillimanite gneiss in the Western Gneiss Region (WGR) and its presence, composition, formation and metamorphic evolution. Peak metamorphism is modelled to T = 750 °C and P around 0.6 GPa. Subsequent retrogression consumes garnet and shows mineral replacement and melt crystallization involving sillimanite, white mica, K-feldspar and quartz. The petrological evolution is in accordance with the investigated eclogites and HP granulites in the northwestern part of WGR.
The paper documents sillimanite gneiss in the Western Gneiss Region (WGR) and its presence,...
