Carbon in mineralized ultramafic intrusions, Caledonides, northern Britain

J. Parnell; Joseph Armstrong; C. Brolly; A. J. Boyce; E. Heptinstall

doi:10.1016/j.lithos.2020.105711

Carbon in mineralized ultramafic intrusions, Caledonides, northern Britain

J. Parnell^* (Corresponding Author), Joseph Armstrong, C. Brolly, A. J. Boyce, E. Heptinstall

^*Corresponding author for this work

Scottish Universities Environmental Research Centre (SUERC)

Research output: Contribution to journal › Article › peer-review

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Abstract

Graphite in Ordovician ultramafic intrusions through Neoproterozoic country rocks in West Aberdeenshire, NE Scotland attests to the mobility of carbon into subduction-related magmas. Pelites in the country rock contain up to 5% organic carbon, and are consequently also sulphide-rich. This occurrence is one of many examples of graphite in ultramafic intrusions. The sedimentary origin of the graphite carbon is indicated by carbon isotope compositions (mean - 19.7%.) in the same range as in the country rocks (mean - 21.6%0. The graphite is spatially and temporally associated with nickel-bearing sulphides, whose precipitation was strongly influenced by incorporation of the carbonaceous, sulphidic country rocks into the intrusions. Raman spectra for graphite in the intrusions show it is fully ordered, deposited from fluid in the magma. Preferential intrusion into pelitic country rocks facilitated the ready assimilation of carbon. In this case reworking of carbon from the crust into intrusions occurred 200 million years after sedimentation, a much longer timescale than most cycling of carbon in subduction zones. (C) 2020 The Author(s). Published by Elsevier B.V.

Original language	English
Article number	105711
Number of pages	10
Journal	Lithos
Volume	374-375
Early online date	31 Jul 2020
DOIs	https://doi.org/10.1016/j.lithos.2020.105711
Publication status	Published - 15 Nov 2020

Bibliographical note

We are grateful to J. Johnston, J. Bowie and A. Boyce for skilled technical support. This work was partly supported by NERC grant NE/M010953/1. Electron Microscopy was performed with the help of J. Still in the ACEMAC Facility at the University of Aberdeen. Samples were donated from the University of Aberdeen (Cairnie sample 6932, Coulins Burn 5524, Allt Nathrach 6992, Dunbennan 11876). We are very grateful for two reviews which helped to clarify the manuscript.

Keywords

graphite
carbon
cumulates
Scotland
DALRADIAN SUPERGROUP
SULFUR ISOTOPE
GRAPHITE DEPOSIT
ROCKS
Carbon
MANTLE
ORIGIN
Cumulates
SULFIDE DEPOSITS
REDUCTION
ACHANKOVIL SHEAR ZONE
Graphite
MAGMA

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10.1016/j.lithos.2020.105711Licence: CC BY-NC-ND

Parnell_et_al_Lithos_CarbonInMineralized_VoR
© 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Final published version, 3.14 MBLicence: CC BY-NC-ND

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@article{ef6e7fd3006048cb84be97846b367fca,

title = "Carbon in mineralized ultramafic intrusions, Caledonides, northern Britain",

abstract = "Graphite in Ordovician ultramafic intrusions through Neoproterozoic country rocks in West Aberdeenshire, NE Scotland attests to the mobility of carbon into subduction-related magmas. Pelites in the country rock contain up to 5% organic carbon, and are consequently also sulphide-rich. This occurrence is one of many examples of graphite in ultramafic intrusions. The sedimentary origin of the graphite carbon is indicated by carbon isotope compositions (mean - 19.7%.) in the same range as in the country rocks (mean - 21.6%0. The graphite is spatially and temporally associated with nickel-bearing sulphides, whose precipitation was strongly influenced by incorporation of the carbonaceous, sulphidic country rocks into the intrusions. Raman spectra for graphite in the intrusions show it is fully ordered, deposited from fluid in the magma. Preferential intrusion into pelitic country rocks facilitated the ready assimilation of carbon. In this case reworking of carbon from the crust into intrusions occurred 200 million years after sedimentation, a much longer timescale than most cycling of carbon in subduction zones. (C) 2020 The Author(s). Published by Elsevier B.V.",

keywords = "graphite, carbon, cumulates, Scotland, DALRADIAN SUPERGROUP, SULFUR ISOTOPE, GRAPHITE DEPOSIT, ROCKS, Carbon, MANTLE, ORIGIN, Cumulates, SULFIDE DEPOSITS, REDUCTION, ACHANKOVIL SHEAR ZONE, Graphite, MAGMA",

author = "J. Parnell and Joseph Armstrong and C. Brolly and Boyce, {A. J.} and E. Heptinstall",

note = "We are grateful to J. Johnston, J. Bowie and A. Boyce for skilled technical support. This work was partly supported by NERC grant NE/M010953/1. Electron Microscopy was performed with the help of J. Still in the ACEMAC Facility at the University of Aberdeen. Samples were donated from the University of Aberdeen (Cairnie sample 6932, Coulins Burn 5524, Allt Nathrach 6992, Dunbennan 11876). We are very grateful for two reviews which helped to clarify the manuscript.",

year = "2020",

month = nov,

day = "15",

doi = "10.1016/j.lithos.2020.105711",

language = "English",

volume = "374-375",

journal = "Lithos",

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AU - Parnell, J.

AU - Armstrong, Joseph

AU - Brolly, C.

AU - Boyce, A. J.

AU - Heptinstall, E.

N1 - We are grateful to J. Johnston, J. Bowie and A. Boyce for skilled technical support. This work was partly supported by NERC grant NE/M010953/1. Electron Microscopy was performed with the help of J. Still in the ACEMAC Facility at the University of Aberdeen. Samples were donated from the University of Aberdeen (Cairnie sample 6932, Coulins Burn 5524, Allt Nathrach 6992, Dunbennan 11876). We are very grateful for two reviews which helped to clarify the manuscript.

PY - 2020/11/15

Y1 - 2020/11/15

N2 - Graphite in Ordovician ultramafic intrusions through Neoproterozoic country rocks in West Aberdeenshire, NE Scotland attests to the mobility of carbon into subduction-related magmas. Pelites in the country rock contain up to 5% organic carbon, and are consequently also sulphide-rich. This occurrence is one of many examples of graphite in ultramafic intrusions. The sedimentary origin of the graphite carbon is indicated by carbon isotope compositions (mean - 19.7%.) in the same range as in the country rocks (mean - 21.6%0. The graphite is spatially and temporally associated with nickel-bearing sulphides, whose precipitation was strongly influenced by incorporation of the carbonaceous, sulphidic country rocks into the intrusions. Raman spectra for graphite in the intrusions show it is fully ordered, deposited from fluid in the magma. Preferential intrusion into pelitic country rocks facilitated the ready assimilation of carbon. In this case reworking of carbon from the crust into intrusions occurred 200 million years after sedimentation, a much longer timescale than most cycling of carbon in subduction zones. (C) 2020 The Author(s). Published by Elsevier B.V.

AB - Graphite in Ordovician ultramafic intrusions through Neoproterozoic country rocks in West Aberdeenshire, NE Scotland attests to the mobility of carbon into subduction-related magmas. Pelites in the country rock contain up to 5% organic carbon, and are consequently also sulphide-rich. This occurrence is one of many examples of graphite in ultramafic intrusions. The sedimentary origin of the graphite carbon is indicated by carbon isotope compositions (mean - 19.7%.) in the same range as in the country rocks (mean - 21.6%0. The graphite is spatially and temporally associated with nickel-bearing sulphides, whose precipitation was strongly influenced by incorporation of the carbonaceous, sulphidic country rocks into the intrusions. Raman spectra for graphite in the intrusions show it is fully ordered, deposited from fluid in the magma. Preferential intrusion into pelitic country rocks facilitated the ready assimilation of carbon. In this case reworking of carbon from the crust into intrusions occurred 200 million years after sedimentation, a much longer timescale than most cycling of carbon in subduction zones. (C) 2020 The Author(s). Published by Elsevier B.V.

KW - graphite

KW - carbon

KW - cumulates

KW - Scotland

KW - DALRADIAN SUPERGROUP

KW - SULFUR ISOTOPE

KW - GRAPHITE DEPOSIT

KW - ROCKS

KW - Carbon

KW - MANTLE

KW - ORIGIN

KW - Cumulates

KW - SULFIDE DEPOSITS

KW - REDUCTION

KW - ACHANKOVIL SHEAR ZONE

KW - Graphite

KW - MAGMA

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U2 - 10.1016/j.lithos.2020.105711

DO - 10.1016/j.lithos.2020.105711

M3 - Article

SN - 0024-4937

VL - 374-375

JO - Lithos

JF - Lithos

M1 - 105711

ER -

Carbon in mineralized ultramafic intrusions, Caledonides, northern Britain

Abstract

Bibliographical note

Keywords

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Aberdeen Centre for Electron Microscopy, Analysis and Characterisation (ACEMAC):

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Carbon in mineralized ultramafic intrusions, Caledonides, northern Britain

Abstract

Bibliographical note

Keywords

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Aberdeen Centre for Electron Microscopy, Analysis and Characterisation (ACEMAC):

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