Geodynamic implications of synchronous norite and TTG formation in the 3 Ga Maniitsoq Norite Belt, West Greenland

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Geodynamic implications of synchronous norite and TTG formation in the 3 Ga Maniitsoq Norite Belt, West Greenland. / Waterton, Pedro; Hyde, William Robert; Tusch, Jonas; Hollis, Julie A.; Kirkland, Christopher L.; Kinney, Carson; Yakymchuk, Chris; Gardiner, Nicholas J; Zakharov, David; Olierook, Hugo K.; Lightfoot, Peter C.; Szilas, Kristoffer.

In: Frontiers in Earth Science, Vol. 8, 562062, 22.09.2020.

Research output: Contribution to journalJournal articleResearchpeer-review

Harvard

Waterton, P, Hyde, WR, Tusch, J, Hollis, JA, Kirkland, CL, Kinney, C, Yakymchuk, C, Gardiner, NJ, Zakharov, D, Olierook, HK, Lightfoot, PC & Szilas, K 2020, 'Geodynamic implications of synchronous norite and TTG formation in the 3 Ga Maniitsoq Norite Belt, West Greenland', Frontiers in Earth Science, vol. 8, 562062. https://doi.org/10.3389/feart.2020.562062

APA

Waterton, P., Hyde, W. R., Tusch, J., Hollis, J. A., Kirkland, C. L., Kinney, C., Yakymchuk, C., Gardiner, N. J., Zakharov, D., Olierook, H. K., Lightfoot, P. C., & Szilas, K. (2020). Geodynamic implications of synchronous norite and TTG formation in the 3 Ga Maniitsoq Norite Belt, West Greenland. Frontiers in Earth Science, 8, [562062]. https://doi.org/10.3389/feart.2020.562062

Vancouver

Waterton P, Hyde WR, Tusch J, Hollis JA, Kirkland CL, Kinney C et al. Geodynamic implications of synchronous norite and TTG formation in the 3 Ga Maniitsoq Norite Belt, West Greenland. Frontiers in Earth Science. 2020 Sep 22;8. 562062. https://doi.org/10.3389/feart.2020.562062

Author

Waterton, Pedro ; Hyde, William Robert ; Tusch, Jonas ; Hollis, Julie A. ; Kirkland, Christopher L. ; Kinney, Carson ; Yakymchuk, Chris ; Gardiner, Nicholas J ; Zakharov, David ; Olierook, Hugo K. ; Lightfoot, Peter C. ; Szilas, Kristoffer. / Geodynamic implications of synchronous norite and TTG formation in the 3 Ga Maniitsoq Norite Belt, West Greenland. In: Frontiers in Earth Science. 2020 ; Vol. 8.

Bibtex

@article{e1b659f405c04db1b27fd3726983b5ac,
title = "Geodynamic implications of synchronous norite and TTG formation in the 3 Ga Maniitsoq Norite Belt, West Greenland",
abstract = "We present new data for the ~3.0 Ga Maniitsoq Norite Belt of the Akia Terrane, West Greenland, with the aim of understanding its petrogenesis. The Maniitsoq Norite Belt is hosted in regional TTG and dioritic orthogneisses, intruded by later sheets of TTG and granite pegmatites, and comprises two main rock types: plagioclase-rich {\textquoteleft}norites{\textquoteright} and pyroxene-rich {\textquoteleft}melanorites{\textquoteright}. Both norites and melanorites have high SiO2 contents (52 – 60 wt% SiO2), high bulk rock Mg# (0.57 – 0.83), and low TiO2 contents (0.1 – 0.7 wt%). Their trace element patterns are defined by depleted HREEs, highly enriched LREEs, negative anomalies in Nb, Ta, and Ti, and variable anomalies in Zr, Hf, and Eu. New zircon U-Pb geochronology data and previously published ages establish an emplacement age of 3013 ± 1 Ma for the majority of the Maniitsoq Norite Belt, with magmatism continuing until 3001 ± 3 Ma. This ~12 Myr period of norite magmatism is coeval with an ongoing period of TTG production in the Akia Terrane. Norite Belt emplacement was closely followed by high temperature, low pressure granulite-facies metamorphism at ~800 °C and < 9 kbar. These conditions imply high temperature gradients (> 900 °C/GPa) and that the norite magmas were emplaced into thin crust and lithosphere. Compositions of the norites and melanorites can be explained by derivation from a single mafic parental melt (~13 wt% MgO), with the norites predominantly accumulating plagioclase and the melanorites predominantly accumulating pyroxene. Evidence from field relationships, the presence of xenocrystic zircon, major element compositions and combined trace element and Hf-isotope modelling suggests the norites were contaminated by assimilation of ~20 – 30% continental TTG crust. Geochemical and Hf-Nd isotopic constraints indicate that the norite mantle source was depleted, and that this depletion occurred significantly before the emplacement of the norite magmas. Contemporaneous production of both TTGs and norite, their emplacement in thin crust, and the rapid transition to high temperature, low pressure granulite-facies metamorphism is best explained by their formation in an ultra-hot orogeny. Formation of norites in this setting may be restricted to > 2.7 Ga, when geothermal gradients were higher on Earth. ",
keywords = "Faculty of Science, Norite, Crustal contamination, TTG and TTG-like gneisses, Nd isotope, Hf isotope, Major element, Trace element (TE), Phase equilibrium modelling, Oxygen isotope (δ18O), Zircon U-Pb dating, Granulite and amphibolite facies, Ultra-hot orogen",
author = "Pedro Waterton and Hyde, {William Robert} and Jonas Tusch and Hollis, {Julie A.} and Kirkland, {Christopher L.} and Carson Kinney and Chris Yakymchuk and Gardiner, {Nicholas J} and David Zakharov and Olierook, {Hugo K.} and Lightfoot, {Peter C.} and Kristoffer Szilas",
year = "2020",
month = sep,
day = "22",
doi = "10.3389/feart.2020.562062",
language = "English",
volume = "8",
journal = "Frontiers in Earth Science",
issn = "2296-6463",
publisher = "Frontiers Research Foundation",

}

RIS

TY - JOUR

T1 - Geodynamic implications of synchronous norite and TTG formation in the 3 Ga Maniitsoq Norite Belt, West Greenland

AU - Waterton, Pedro

AU - Hyde, William Robert

AU - Tusch, Jonas

AU - Hollis, Julie A.

AU - Kirkland, Christopher L.

AU - Kinney, Carson

AU - Yakymchuk, Chris

AU - Gardiner, Nicholas J

AU - Zakharov, David

AU - Olierook, Hugo K.

AU - Lightfoot, Peter C.

AU - Szilas, Kristoffer

PY - 2020/9/22

Y1 - 2020/9/22

N2 - We present new data for the ~3.0 Ga Maniitsoq Norite Belt of the Akia Terrane, West Greenland, with the aim of understanding its petrogenesis. The Maniitsoq Norite Belt is hosted in regional TTG and dioritic orthogneisses, intruded by later sheets of TTG and granite pegmatites, and comprises two main rock types: plagioclase-rich ‘norites’ and pyroxene-rich ‘melanorites’. Both norites and melanorites have high SiO2 contents (52 – 60 wt% SiO2), high bulk rock Mg# (0.57 – 0.83), and low TiO2 contents (0.1 – 0.7 wt%). Their trace element patterns are defined by depleted HREEs, highly enriched LREEs, negative anomalies in Nb, Ta, and Ti, and variable anomalies in Zr, Hf, and Eu. New zircon U-Pb geochronology data and previously published ages establish an emplacement age of 3013 ± 1 Ma for the majority of the Maniitsoq Norite Belt, with magmatism continuing until 3001 ± 3 Ma. This ~12 Myr period of norite magmatism is coeval with an ongoing period of TTG production in the Akia Terrane. Norite Belt emplacement was closely followed by high temperature, low pressure granulite-facies metamorphism at ~800 °C and < 9 kbar. These conditions imply high temperature gradients (> 900 °C/GPa) and that the norite magmas were emplaced into thin crust and lithosphere. Compositions of the norites and melanorites can be explained by derivation from a single mafic parental melt (~13 wt% MgO), with the norites predominantly accumulating plagioclase and the melanorites predominantly accumulating pyroxene. Evidence from field relationships, the presence of xenocrystic zircon, major element compositions and combined trace element and Hf-isotope modelling suggests the norites were contaminated by assimilation of ~20 – 30% continental TTG crust. Geochemical and Hf-Nd isotopic constraints indicate that the norite mantle source was depleted, and that this depletion occurred significantly before the emplacement of the norite magmas. Contemporaneous production of both TTGs and norite, their emplacement in thin crust, and the rapid transition to high temperature, low pressure granulite-facies metamorphism is best explained by their formation in an ultra-hot orogeny. Formation of norites in this setting may be restricted to > 2.7 Ga, when geothermal gradients were higher on Earth.

AB - We present new data for the ~3.0 Ga Maniitsoq Norite Belt of the Akia Terrane, West Greenland, with the aim of understanding its petrogenesis. The Maniitsoq Norite Belt is hosted in regional TTG and dioritic orthogneisses, intruded by later sheets of TTG and granite pegmatites, and comprises two main rock types: plagioclase-rich ‘norites’ and pyroxene-rich ‘melanorites’. Both norites and melanorites have high SiO2 contents (52 – 60 wt% SiO2), high bulk rock Mg# (0.57 – 0.83), and low TiO2 contents (0.1 – 0.7 wt%). Their trace element patterns are defined by depleted HREEs, highly enriched LREEs, negative anomalies in Nb, Ta, and Ti, and variable anomalies in Zr, Hf, and Eu. New zircon U-Pb geochronology data and previously published ages establish an emplacement age of 3013 ± 1 Ma for the majority of the Maniitsoq Norite Belt, with magmatism continuing until 3001 ± 3 Ma. This ~12 Myr period of norite magmatism is coeval with an ongoing period of TTG production in the Akia Terrane. Norite Belt emplacement was closely followed by high temperature, low pressure granulite-facies metamorphism at ~800 °C and < 9 kbar. These conditions imply high temperature gradients (> 900 °C/GPa) and that the norite magmas were emplaced into thin crust and lithosphere. Compositions of the norites and melanorites can be explained by derivation from a single mafic parental melt (~13 wt% MgO), with the norites predominantly accumulating plagioclase and the melanorites predominantly accumulating pyroxene. Evidence from field relationships, the presence of xenocrystic zircon, major element compositions and combined trace element and Hf-isotope modelling suggests the norites were contaminated by assimilation of ~20 – 30% continental TTG crust. Geochemical and Hf-Nd isotopic constraints indicate that the norite mantle source was depleted, and that this depletion occurred significantly before the emplacement of the norite magmas. Contemporaneous production of both TTGs and norite, their emplacement in thin crust, and the rapid transition to high temperature, low pressure granulite-facies metamorphism is best explained by their formation in an ultra-hot orogeny. Formation of norites in this setting may be restricted to > 2.7 Ga, when geothermal gradients were higher on Earth.

KW - Faculty of Science

KW - Norite

KW - Crustal contamination

KW - TTG and TTG-like gneisses

KW - Nd isotope

KW - Hf isotope

KW - Major element

KW - Trace element (TE)

KW - Phase equilibrium modelling

KW - Oxygen isotope (δ18O)

KW - Zircon U-Pb dating

KW - Granulite and amphibolite facies

KW - Ultra-hot orogen

U2 - 10.3389/feart.2020.562062

DO - 10.3389/feart.2020.562062

M3 - Journal article

VL - 8

JO - Frontiers in Earth Science

JF - Frontiers in Earth Science

SN - 2296-6463

M1 - 562062

ER -

ID: 247456356