Metamorphic microdiamond formation is controlled by water
activity, phase transitions and temperature

J 2021

Metamorphic microdiamond formation is controlled by water activity, phase transitions and temperature

KOTKOVÁ, Jana, Y. FEDORTCHOUK, R. WIRTH a M. J. WHITEHOUSE

Základní údaje

Originální název

Metamorphic microdiamond formation is controlled by water activity, phase transitions and temperature

Autoři

KOTKOVÁ, Jana (203 Česká republika, garant, domácí), Y. FEDORTCHOUK, R. WIRTH a M. J. WHITEHOUSE

Vydání

Scientific Reports, Nature Research, 2021, 2045-2322

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 4.996

Kód RIV

RIV/00216224:14310/21:00118937

Organizační jednotka

Přírodovědecká fakulta

DOI

http://dx.doi.org/10.1038/s41598-021-87272-1

UT WoS

000639562100014

Klíčová slova anglicky

microdiamond; ultrahigh-pressure metamorphism; phase relations; water activity; carbon isotopes; deep subduction; Bohemian Massif

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 21. 10. 2021 10:35, Mgr. Marie Šípková, DiS.

Anotace

V originále

Metamorphic diamonds hosted by major and accessory phases in ultrahigh-pressure (UHP) metamorphic terranes represent important indicators of deep subduction and exhumation of continental crust at convergent plate boundaries. However, their nucleation and growth mechanisms are not well understood due to their small size and diversity. The Bohemian microdiamond samples represent a unique occurrence of monocrystalline octahedral and polycrystalline cubo-octahedral microdiamonds in two different metasedimentary rock types. By combining new and published data on microdiamonds (morphology, resorption, associated phases, carbon isotope composition) with P–T constraints from their host rocks, we demonstrate that the peak P–T conditions for the diamond-bearing UHP rocks cluster along water activity-related phase transitions that determine the microdiamond features. With increasing temperature, the diamond-forming medium changes from aqueous fluid to hydrous melt, and diamond morphology evolves from cubo-octahedral to octahedral. The latter is restricted to the UHP-UHT rocks exceeding 1100 °C, which is above the incongruent melting of phengite, where microdiamonds nucleate along a prograde P–T path in silicate-carbonate hydrous melt. The observed effect of temperature on diamond morphology supports experimental data on diamond growth and can be used for examining growth conditions of cratonic diamonds from kimberlites, which are dominated by octahedra and their resorbed forms.

Návaznosti

GA18-27454S, projekt VaV

Název: Přenos prvků v prostředí hluboké subdukce: doklady z ultravysokotlakých metamorfovaných terénů (Akronym: element transfer)

Investor: Grantová agentura ČR, Přenos prvků v prostředí hluboké subdukce: doklady z ultravysokotlakých metamorfovaných terénů

Citovat

KOTKOVÁ, Jana, Y. FEDORTCHOUK, R. WIRTH a M. J. WHITEHOUSE. Metamorphic microdiamond formation is controlled by water activity, phase transitions and temperature. Scientific Reports. Nature Research, 2021, roč. 11, č. 1, s. 7694-7706. ISSN 2045-2322. Dostupné z: https://dx.doi.org/10.1038/s41598-021-87272-1.

@article{1761856,
   author = {Kotková, Jana and Fedortchouk, Y. and Wirth, R. and Whitehouse, M. J.},
   article_number = {1},
   doi = {http://dx.doi.org/10.1038/s41598-021-87272-1},
   keywords = {microdiamond; ultrahigh-pressure metamorphism; phase relations; water activity; carbon isotopes; deep subduction; Bohemian Massif},
   language = {eng},
   issn = {2045-2322},
   journal = {Scientific Reports},
   title = {Metamorphic microdiamond formation is controlled by water activity, phase transitions and temperature},
   url = {https://www.nature.com/articles/s41598-021-87272-1},
   volume = {11},
   year = {2021}
}

TY  - JOUR
ID  - 1761856
AU  - Kotková, Jana - Fedortchouk, Y. - Wirth, R. - Whitehouse, M. J.
PY  - 2021
TI  - Metamorphic microdiamond formation is controlled by water activity, phase transitions and temperature
JF  - Scientific Reports
VL  - 11
IS  - 1
SP  - 7694
EP  - 7694
PB  - Nature Research
SN  - 20452322
KW  - microdiamond
KW  - ultrahigh-pressure metamorphism
KW  - phase relations
KW  - water activity
KW  - carbon isotopes
KW  - deep subduction
KW  - Bohemian Massif
UR  - https://www.nature.com/articles/s41598-021-87272-1
N2  - Metamorphic diamonds hosted by major and accessory phases in ultrahigh-pressure (UHP) metamorphic terranes represent important indicators of deep subduction and exhumation of continental crust at convergent plate boundaries. However, their nucleation and growth mechanisms are not well understood due to their small size and diversity. The Bohemian microdiamond samples represent a unique occurrence of monocrystalline octahedral and polycrystalline cubo-octahedral microdiamonds in two different metasedimentary rock types. By combining new and published data on microdiamonds (morphology, resorption, associated phases, carbon isotope composition) with P–T constraints from their host rocks, we demonstrate that the peak P–T conditions for the diamond-bearing UHP rocks cluster along water activity-related phase transitions that determine the microdiamond features. With increasing temperature, the diamond-forming medium changes from aqueous fluid to hydrous melt, and diamond morphology evolves from cubo-octahedral to octahedral. The latter is restricted to the UHP-UHT rocks exceeding 1100 °C, which is above the incongruent melting of phengite, where microdiamonds nucleate along a prograde P–T path in silicate-carbonate hydrous melt. The observed effect of temperature on diamond morphology supports experimental data on diamond growth and can be used for examining growth conditions of cratonic diamonds from kimberlites, which are dominated by octahedra and their resorbed forms.
ER  -

KOTKOVÁ, Jana, Y. FEDORTCHOUK, R. WIRTH a M. J. WHITEHOUSE. Metamorphic microdiamond formation is controlled by water activity, phase transitions and temperature. \textit{Scientific Reports}. Nature Research, 2021, roč.~11, č.~1, s.~7694-7706. ISSN~2045-2322. Dostupné z: https://dx.doi.org/10.1038/s41598-021-87272-1.

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