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Journal articles on the topic 'Whiteschist'

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Published: 10 December 2022

Last updated: 29 January 2023

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1

Marger, Katharina, Cindy Luisier, Lukas P. Baumgartner, Benita Putlitz, Barbara L. Dutrow, Anne-Sophie Bouvier, and Andrea Dini. "Origin of Monte Rosa whiteschist from in-situ tourmaline and quartz oxygen isotope analysis by SIMS using new tourmaline reference materials." American Mineralogist 104, no. 10 (October 1, 2019): 1503–20. http://dx.doi.org/10.2138/am-2019-7012.

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Abstract A series of tourmaline reference materials are developed for in situ oxygen isotope analysis by secondary ion mass spectrometry (SIMS), which allow study of the tourmaline compositions found in most igneous and metamorphic rocks. The new reference material was applied to measure oxygen isotope composition of tourmaline from metagranite, meta-leucogranite, and whiteschist from the Monte Rosa nappe (Western Alps). The protolith and genesis of whiteschist are highly debated in the literature. Whiteschists occur as 10 to 50 m tube-like bodies within the Permian Monte Rosa granite. They consist of chloritoid, talc, phengite, and quartz, with local kyanite, garnet, tourmaline, and carbonates. Whiteschist tourmaline is characterized by an igneous core and a dravitic overgrowth (XMg > 0.9). The core reveals similar chemical composition and zonation as meta-leucogranitic tourmaline (XMg = 0.25, δ18O = 11.3–11.5‰), proving their common origin. Dravitic overgrowths in whiteschists have lower oxygen isotope compositions (8.9–9.5‰). Tourmaline in metagranite is an intermediate schorl-dravite with XMg of 0.50. Oxygen isotope data reveal homogeneous composition for metagranite and meta-leucogranite tourmalines of 10.4–11.3‰ and 11.0–11.9‰, respectively. Quartz inclusions in both meta-igneous rocks show the same oxygen isotopic composition as the quartz in the matrix (13.6–13.9‰). In whiteschist the oxygen isotope composition of quartz included in tourmaline cores lost their igneous signature, having the same values as quartz in the matrix (11.4–11.7‰). A network of small fractures filled with dravitic tourmaline can be observed in the igneous core and suggested to serve as a connection between included quartz and matrix, and lead to recrystallization of the inclusion. In contrast, the igneous core of the whiteschist tourmaline fully retained its magmatic oxygen isotope signature, indicating oxygen diffusion is extremely slow in tourmaline. Tourmaline included in high-pressure chloritoid shows the characteristic dravitic overgrowth, demonstrating that chloritoid grew after the metasomatism responsible for the whiteschist formation, but continued to grow during the Alpine metamorphism. Our data on tourmaline and quartz show that tourmaline-bearing white-schists originated from the related meta-leucogranites, which were locally altered by late magmatic hydrothermal fluids prior to Alpine high-pressure metamorphism.

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2

JOHNSON, S. P. "High fO2 Metasomatism During Whiteschist Metamorphism, Zambezi Belt, Northern Zimbabwe." Journal of Petrology 43, no. 2 (February 1, 2002): 271–90. http://dx.doi.org/10.1093/petrology/43.2.271.

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3

BEANE, R. J., and C. K. FIELD. "Kyanite deformation in whiteschist of the ultrahigh-pressure metamorphic Kokchetav Massif, Kazakhstan." Journal of Metamorphic Geology 25, no. 2 (February 2007): 117–28. http://dx.doi.org/10.1111/j.1525-1314.2007.00692.x.

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4

Rolfo, Franco, Roberto Compagnoni, Shutong Xu, and Laili Jiang. "First report of felsic whiteschist in the ultrahigh-pressure metamorphic belt of Dabie Shan, China." European Journal of Mineralogy 12, no. 4 (July 17, 2000): 883–98. http://dx.doi.org/10.1127/0935-1221/2000/0012-0883.

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5

FAN, Hongrui. "Fluid inclusions in whiteschist in the ultrahigh-pressure metamorphic belt of Dabie Shan, China." Chinese Science Bulletin 47, no. 12 (2002): 1028. http://dx.doi.org/10.1360/02tb9231.

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6

Fan, Hongrui, Jingbo Liu, Jinghui Guo, Kai Ye, and Bolin Cong. "Fluid inclusions in whiteschist in the ultrahigh-pressure metamorphic belt of Dabie Shan, China." Chinese Science Bulletin 47, no. 12 (June 2002): 1028–32. http://dx.doi.org/10.1007/bf02907576.

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7

Hwang, Shyh-Lung, Pouyan Shen, Hao-Tsu Chu, and Tzen-Fu Yui. "A New Occurrence and New Data on Akdalaite, a Retrograde Mineral from UHP Whiteschist, Kokchetav Massif, Northern Kazakhstan." International Geology Review 48, no. 8 (August 2006): 754–64. http://dx.doi.org/10.2747/0020-6814.48.8.754.

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8

John, Timm, Volker Schenk, Klaus Mezger, and Francis Tembo. "Timing andPTEvolution of Whiteschist Metamorphism in the Lufilian Arc–Zambezi Belt Orogen (Zambia): Implications for the Assembly of Gondwana." Journal of Geology 112, no. 1 (January 2004): 71–90. http://dx.doi.org/10.1086/379693.

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9

Chen, Yi-Xiang, Kun Zhou, Yong-Fei Zheng, and Hans-Peter Schertl. "Zircon geochemical constraints on the protolith nature and metasomatic process of the Mg-rich whiteschist from the Western Alps." Chemical Geology 467 (September 2017): 177–95. http://dx.doi.org/10.1016/j.chemgeo.2017.08.013.

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10

Tian, Ye, Yilin Xiao, Yi-Xiang Chen, He Sun, Haiyang Liu, Fengtai Tong, Jie-Hua Yang, and Hans-Peter Schertl. "Serpentinite-derived low δ7Li fluids in continental subduction zones: Constraints from the fluid metasomatic rocks (whiteschist) from the Dora-Maira Massif, Western Alps." Lithos 348-349 (December 2019): 105177. http://dx.doi.org/10.1016/j.lithos.2019.105177.

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11

Parkinson, Chris D. "Coesite inclusions and prograde compositional zonation of garnet in whiteschist of the HP-UHPM Kokchetav massif, Kazakhstan: a record of progressive UHP metamorphism." Lithos 52, no. 1-4 (April 2000): 215–33. http://dx.doi.org/10.1016/s0024-4937(99)00092-4.

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12

Chen, Yi-Xiang, Wenning Lu, Yongsheng He, Hans-Peter Schertl, Yong-Fei Zheng, Jia-Wei Xiong, and Kun Zhou. "Tracking Fe mobility and Fe speciation in subduction zone fluids at the slab-mantle interface in a subduction channel: A tale of whiteschist from the Western Alps." Geochimica et Cosmochimica Acta 267 (December 2019): 1–16. http://dx.doi.org/10.1016/j.gca.2019.09.020.

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13

Franz, Leander, Rolf L. Romer, and Christian de Capitani. "Protoliths and phase petrology of whiteschists." Contributions to Mineralogy and Petrology 166, no. 1 (March 26, 2013): 255–74. http://dx.doi.org/10.1007/s00410-013-0874-5.

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14

Schreyer, Werner. "Experimental Studies on Metamorphism of Crustal Rocks Under Mantle Pressures." Mineralogical Magazine 52, no. 364 (March 1988): 1–26. http://dx.doi.org/10.1180/minmag.1988.052.364.01.

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AbstractMetamorphic rocks of undoubted crustal origin have been described in recent years, principally from Mediterranean collision zones that have been subjected to PT conditions along very low geothermal gradients (∼ 7°C/km) and have reached pressures up to 30 kbar. MgAl-rich metapelites develop particularly diagnostic high-pressure minerals and mineral assemblages that have been and are being studied experimentally in model systems involving the components K2O, MgO, Al2O3, TiO2, SiO2, P2O5, and H2O up to pressures of 50 kbar and temperatures of 1000°C.In the present review the following synthetic phases and phase assemblages are discussed, emphasizing their water-pressure-temperature stability fields (approximated in parentheses here), their reaction relationships, and their known or potential occurrences in metamorphic rocks. Sudoite (0 to ∼ 12 kbar, 150? to 380°C) occurs in very low-grade metapelites. Mg-carpholite (∼ 7 to ∼ 45 kbar, ∼ 200 to 600°C) is found in subducted metabauxites, metapelites, and related quartz veins. Mg-chloritoid (18 to 45 kbar?; 400 to 760°C) has not been found in nature as pure or nearly pure end-member; it requires silica-deficient environments. Yoderite, known in nature only from a single talc-kyanite schist occurrence, has only a small stability field (9 to 18 kbar?, 700 to 870°C?), cannot coexist with quartz, but may be stabilized by Fe3+. Pyrope (∼ 15 to at least 50 kbar, ∼ 700°C to melting), with or without relic coesite inclusions, occurs spectacularly in quartzites. Mg-staurolite (∼ 14 to some 90 kbar?, 700 to 1000°C), recently discovered as inclusions in pyrope, requires silica-deficiency. MgMgAl-pumpellyite is a new synthetic phase in which Mg totally replaces Ca of normal pumpellyite; because of its very high-pressure, low-temperature stability (∼ 37 to at least 55 kbar, < 400 to 780°C) it may not form within our globe. Ellenbergerite, the new high-pressure mineral forming inclusions in pyrope, apparently exhibits a rather composition-dependent stability with Ti-ellenbergerite, requiring higher pressures (> 20 kbar) than P-bearing, Ti-free members; a pure hydrous Mg-phosphate with ellenbergerite structure was synthesized at 10 kbar. Phengites, the widespread MgSi-substituted muscovites, require increasingly high water pressures (up to ∼ 20 kbar) for higher degrees of substitution, but the Al-celadonite end-member is not stable under any conditions; the compositions of phengites coexisting with limiting assemblages such as phlogopite, K-feldspar, and an SiO2 phase are useful geobarometers. The common assemblage Mg-chlorite + Al2SiO5 (mainly kyanite) has an extensive stability field ranging from near zero to 31 kbar at temperatures varying from some 320 to ∼ 760°C depending on pressure. The whiteschist assemblage talc + kyanite (6 to ∼ 45 kbar, 550 to 810°C) plays an important role in collision zone metamorphism as it forms from the greenschist assemblage chlorite + quartz at low grades but is also known to break down into pyrope + coesite at the highest grade observed thus far. The assemblage talc-phengite (11 to at least 35 kbar, 300? to 820°C depending on pressure), on the other hand, is well known from subducted metapelites. At pressures of 15–20 kbar and temperatures of 400–650°C a very K,Mg-rich, siliceous fluid forms as a consequence of the mutual reaction of the minerals K-feldspar and phlogopite (biotite) which are very common in crustal rocks including granites. Such fluids are bound to cause metasomatism in neighbouring mantle rocks which, upon subsequent increase of temperature, produce post-collisional ultrapotassic, lamproitic melts.

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15

Grew, Edward S., Andrei K. Litinenko, and Nikolai N. Pertsev. "In search of whiteschists and kornerupine in the southwestern Pamirs, USSR." Episodes 13, no. 4 (December 1, 1990): 270–74. http://dx.doi.org/10.18814/epiiugs/1990/v13i4/007.

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16

Hubbard, M. S., E. S. Grew, K. V. Hodges, M. G. Yates, and N. N. Pertsev. "Neogene cooling and exhumation of upper-amphibolite-facies `whiteschists' in the southwest Pamir Mountains, Tajikistan." Tectonophysics 305, no. 1-3 (May 1999): 325–37. http://dx.doi.org/10.1016/s0040-1951(99)00012-8.

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17

Sharp, Z. D., E. J. Essene, and J. C. Hunziker. "Stable isotope geochemistry and phase equilibria of coesite-bearing whiteschists, Dora Maira Massif, western Alps." Contributions to Mineralogy and Petrology 114, no. 1 (May 1993): 1–12. http://dx.doi.org/10.1007/bf00307861.

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18

JÖNS, NIELS, and VOLKER SCHENK. "Petrology of Whiteschists and Associated Rocks at Mautia Hill (Tanzania): Fluid Infiltration during High-Grade Metamorphism?" Journal of Petrology 45, no. 10 (August 27, 2004): 1959–81. http://dx.doi.org/10.1093/petrology/egh044.

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19

Alessio, Brandon L., and David E. Kelsey. "On yoderite: Using calculated phase equilibria to investigate its rarity in the geological record of whiteschists." Journal of Metamorphic Geology 36, no. 3 (December 15, 2017): 297–314. http://dx.doi.org/10.1111/jmg.12293.

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20

Cosca, M. A., R. Caby, and F. Bussy. "Geochemistry and 40Ar/39Ar geochronology of pseudotachylyte associated with UHP whiteschists from the Dora Maira massif, Italy." Tectonophysics 402, no. 1-4 (June 2005): 93–110. http://dx.doi.org/10.1016/j.tecto.2004.12.033.

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21

Munz, Ingrid Anne. "Whiteschists and orthoamphibole-cordierite rocks and the P-T-t path of the Modum Complex, south Norway." Lithos 24, no. 3 (May 1990): 181–99. http://dx.doi.org/10.1016/0024-4937(90)90031-u.

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22

FERRANDO, S., M. L. FREZZOTTI, M. PETRELLI, and R. COMPAGNONI. "Metasomatism of continental crust during subduction: the UHP whiteschists from the Southern Dora-Maira Massif (Italian Western Alps)." Journal of Metamorphic Geology 27, no. 9 (December 2009): 739–56. http://dx.doi.org/10.1111/j.1525-1314.2009.00837.x.

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23

Adjerid, Zouhir, Gaston Godard, and Khadidja Ouzegane. "High-pressure whiteschists from the Ti-N-Eggoleh area (Central Hoggar, Algeria): A record of Pan-African oceanic subduction." Lithos 226 (June 2015): 201–16. http://dx.doi.org/10.1016/j.lithos.2015.02.013.

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24

Grew, Edward S., Nikolai N. Pertsev, Stanislav Vrána, Martin G. Yates, Charles K. Shearer, and Michael Wiedenbeck. "Kornerupine parageneses in whiteschists and other magnesian rocks: is kornerupine + talc a high-pressure assemblage equivalent to tourmaline + orthoamphibole?" Contributions to Mineralogy and Petrology 131, no. 1 (March 30, 1998): 22–38. http://dx.doi.org/10.1007/s004100050376.

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25

Compagnoni, Roberto, and Takao Hirajima. "Superzoned garnets in the coesite-bearing Brossasco-Isasca Unit, Dora-Maira massif, Western Alps, and the origin of the whiteschists." Lithos 57, no. 4 (July 2001): 219–36. http://dx.doi.org/10.1016/s0024-4937(01)00041-x.

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26

YANG, JIAN-JUN, and ROGER POWELL. "Calculated Phase Relations in the System Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O with Applications to UHP Eclogites and Whiteschists." Journal of Petrology 47, no. 10 (July 19, 2006): 2047–71. http://dx.doi.org/10.1093/petrology/egl036.

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27

Cutten, Huntly, Simon P. Johnson, and Bert De Waele. "Protolith Ages and Timing of Metasomatism Related to the Formation of Whiteschists at Mautia Hill, Tanzania: Implications for the Assembly of Gondwana." Journal of Geology 114, no. 6 (November 2006): 683–98. http://dx.doi.org/10.1086/507614.

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28

Demény, Attila, Zachary D. Sharp, and Hans-Rudolf Pfeifer. "Mg-metasomatism and formation conditions of Mg-chlorite-muscovite-quartzphyllites (leucophyllites) of the Eastern Alps (W. Hungary) and their relations to Alpine whiteschists." Contributions to Mineralogy and Petrology 128, no. 2-3 (July 25, 1997): 247–60. http://dx.doi.org/10.1007/s004100050306.

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29

Faryad, S. W. "Metamorphic evolution of the Precambrian South Badakhshan block, based on mineral reactions in metapelites and metabasites associated with whiteschists from Sare Sang (Western Hindu Kush, Afghanistan)." Precambrian Research 98, no. 3-4 (December 1999): 223–41. http://dx.doi.org/10.1016/s0301-9268(99)00051-0.

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30

Luisier, Cindy, Lukas P. Baumgartner, Benita Putlitz, and Torsten Vennemann. "Whiteschist genesis through metasomatism and metamorphism in the Monte Rosa nappe (Western Alps)." Contributions to Mineralogy and Petrology 176, no. 1 (January 2021). http://dx.doi.org/10.1007/s00410-020-01759-0.

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AbstractWhiteschists from the Monte Rosa Nappe were examined in the field as well as with petrographic, geochemical, and isotopic methods to constrain the controversial origin of these rocks in their Alpine metamorphic context. Whiteschists occur as ellipsoidal-shaped, decametric-sized bodies, within a Permian metagranite, and consist mainly of chloritoid, talc, phengite, and quartz. The transition from whiteschist to metagranite is marked by multiple sharp mineralogical boundaries defining concentric zones unrelated to Alpine deformation. The development of reaction zones, as well as the geometry of the whiteschist suggest a pervasive fluid infiltration, facilitated and canalized by reaction fingering. Whole-rock compositions of whiteschists and metagranites indicate an enrichment in MgO and H2O and depletion of Na2O, CaO, Ba, Sr, Pb, and Zn in the whiteschist relative to the metagranite. Trace- and rare-earth elements, together with all other major elements, notably K2O and SiO2, were within uncertainty not mobile. Such a K and Si saturated, Na undersaturated fluid is not compatible with previous interpretations of fluids derived from ultramafic rocks, evaporites, or Mg-enriched seawater due to mantle interactions. Together with the large variations in δD and δ18O values, this indicates large fluid fluxes during metasomatism. Calculated δD and δ18O values of fluids in equilibrium with the whiteschist support a magmatic–hydrothermal fluid source, as does the chemical alteration pattern. Bulk rock 87Sr/86Sr ratios in whiteschists confirm a pre-Alpine age of fluid infiltration. The 87Sr/86Sr ratios in whiteschists were subsequently partially homogenized in a closed system during Alpine metamorphism. In conclusion, the granite was locally affected by late magmatic–hydrothermal alteration, which resulted in sericite–chlorite alteration zones in the granite. The entire nappe underwent high-pressure metamorphism during the Alpine orogeny and the mineralogy of the whiteschist was produced during dehydration of the metasomatic assemblage under otherwise closed-system metamorphism. While each whiteschist locality needs to be studied in detail, this in-depth study suggests that many whiteschists found in granitic bodies in the Alps might be of similar origin.

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31

Vaughan-Hammon, Joshua D., Cindy Luisier, Lukas P. Baumgartner, and Stefan M. Schmalholz. "Alpine peak pressure and tectono-metamorphic history of the Monte Rosa nappe: evidence from the cirque du Véraz, upper Ayas valley, Italy." Swiss Journal of Geosciences 114, no. 1 (October 29, 2021). http://dx.doi.org/10.1186/s00015-021-00397-3.

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AbstractThe Monte Rosa nappe consists of a wide range of lithologies that record conditions associated with peak Alpine metamorphism. While peak temperature conditions inferred from previous studies largely agree, variable peak pressures have been estimated for the Alpine high-pressure metamorphic event. Small volumes of whiteschist lithologies with the assemblage chloritoid + phengite + talc + quartz record peak pressures up to 0.6 GPa higher compared to associated metapelitic and metagranitic lithologies, which yield a peak pressure of ca. 1.6 GPa. The reason for this pressure difference is disputed, and proposed explanations include tectonic mixing of rocks from different burial depths (mélange) or local deviations of the pressure from the lithostatic value caused by heterogeneous stress conditions between rocks of contrasting mechanical properties. We present results of detailed field mapping, structural analysis and a new geological map for a part of the Monte Rosa nappe exposed at the cirque du Véraz field area (head of the Ayas valley, Italy). Results of the geological mapping and structural analysis shows the structural coherency within the western portions of the Monte Rosa nappe. This structural coherency falsifies the hypothesis of a tectonic mélange as reason for peak pressure variations. Structural analysis indicates two major Alpine deformation events, in agreement with earlier studies: (1) north-directed nappe emplacement, and (2) south-directed backfolding. We also analyze a newly discovered whiteschist body, which is located at the intrusive contact between Monte Rosa metagranite and surrounding metapelites. This location is different to previous whiteschist occurrences, which were entirely embedded within metagranite. Thermodynamic calculations using metamorphic assemblage diagrams resulted in 2.1 ± 0.2 GPa and 560 ± 20 °C for peak Alpine metamorphic conditions. These results agree with metamorphic conditions inferred for previously investigated nearby whiteschist outcrops embedded in metagranite. The new results, hence, confirm the peak pressure differences between whiteschists and the metagranite and metapelite. To better constrain the prograde pressure–temperature history of the whiteschist, we compare measured Mg zoning in chloritoid with Mg zoning predicted by fractional crystallization pseudo-section modelling for several hypothetical pressure–temperature paths. In order to reach a ca. 0.6 GPa higher peak pressure compared to the metapelite and metagranite, our results suggest that the whiteschist likely deviated from the prograde burial path recorded in metapelite and metagranite lithologies. However, the exact conditions at which the whiteschist pressure deviated are still contentious due to the strong temperature dependency of Mg partitioning in whiteschist assemblages. Our pseudo-section results suggest at least that there was no dramatic isothermal pressure increase recorded in the whiteschist.

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32

"Interplay between fluid circulation and Alpine metamorphism in the Monte Rosa whiteschist from white mica and quartz in situ oxygen isotope analysis by SIMS." American Mineralogist, June 1, 2021. http://dx.doi.org/10.2138/am-2020-7523.

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33

Campomenosi, Nicola, Marco Scambelluri, Ross J. Angel, Joerg Hermann, Mattia L. Mazzucchelli, Boriana Mihailova, Francesca Piccoli, and Matteo Alvaro. "Using the elastic properties of zircon-garnet host-inclusion pairs for thermobarometry of the ultrahigh-pressure Dora-Maira whiteschists: problems and perspectives." Contributions to Mineralogy and Petrology 176, no. 5 (April 22, 2021). http://dx.doi.org/10.1007/s00410-021-01793-6.

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AbstractThe ultrahigh-pressure (UHP) whiteschists of the Brossasco-Isasca unit (Dora-Maira Massif, Western Alps) provide a natural laboratory in which to compare results from classical pressure (P)–temperature (T) determinations through thermodynamic modelling with the emerging field of elastic thermobarometry. Phase equilibria and chemical composition of three garnet megablasts coupled with Zr-in-rutile thermometry of inclusions constrain garnet growth within a narrow P–T range at 3–3.5 GPa and 675–720 °C. On the other hand, the zircon-in-garnet host-inclusion system combined with Zr-in-rutile thermometry would suggest inclusion entrapment conditions below 1.5 GPa and 650 °C that are inconsistent with the thermodynamic modelling and the occurrence of coesite as inclusion in the garnet rims. The observed distribution of inclusion pressures cannot be explained by either zircon metamictization, or by the presence of fluids in the inclusions. Comparison of the measured inclusion strains with numerical simulations shows that post-entrapment plastic relaxation of garnet from metamorphic peak conditions down to 0.5 GPa and 600–650 °C, on the retrograde path, best explains the measured inclusion pressures and their disagreement with the results of phase equilibria modelling. This study suggests that the zircon-garnet couple is more reliable at relatively low temperatures (< 600 °C), where entrapment conditions are well preserved but chemical equilibration might be sluggish. On the other hand, thermodynamic modelling appears to be better suited for higher temperatures where rock-scale equilibrium can be achieved more easily but the local plasticity of the host-inclusion system might prevent the preservation of the signal of peak metamorphic conditions in the stress state of inclusions. Currently, we cannot define a precise threshold temperature for resetting of inclusion pressures. However, the application of both chemical and elastic thermobarometry allows a more detailed interpretation of metamorphic P–T paths.

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