Proterozoic granulite formation driven by mafic magmatism: An example from the Fraser Range Metamorphics, Western Australia

Chris Clark, Christopher L. Kirkland, Catherine V. Spaggiari, Chris Oorschot, Michael T.D. Wingate, Richard J. Taylor

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Elevated heat flow and mafic magmatism during lithospheric extension have often been invoked as a mechanism to drive high-temperature low-pressure metamorphism that produces granulite facies mineral assemblages. Typically, however, evidence of the contemporaneous heat source, such as coeval mafic magmatism, is absent. In this study, we present pressure-temperature (P-T) pseudosection analysis combined with U-Pb isotopic data from zircon and monazite that constrain both the conditions and timing of granulite facies metamorphism in the Fraser Range Metamorphics of the Albany-Fraser Orogen in southern Western Australia. These results also elucidate the extremely rapid timing of, sequentially, deposition of sedimentary protoliths, mafic magmatism, partial melting, and metamorphism within the Fraser Zone during the Mesoproterozoic. The youngest detrital zircons, together with the magmatic ages of intrusive rocks, constrain the depositional age of the protoliths to the Fraser Range Metamorphics to between 1334 and 1293. Ma. Peak metamorphic conditions at c. 1290. Ma were c. 850. °C at pressures of 7-9. kbar. Peak metamorphism was followed by a period of isobaric cooling at pressures of c. 9. kbar. U-Pb zircon ages from leucosomes and metamorphic overgrowths in the metapelitic rocks indicate crystallization of partial melts at 1290. Ma, essentially coincident with the emplacement of mafic rocks at 1292. Ma. In situ analyses of both matrix hosted monazite and monazite inclusions in garnet yield ages between 1285 and 1268. Ma, with no significant age difference between monazite in the two textural positions. Cooling of the Fraser Zone below the Rb-Sr biotite closure temperature (~400. °C) occurred at 1260. Ma. Cooling and strengthening of the Fraser Zone rendered it less susceptible to subsequent tectonic events that affected rocks to the north and south of this resistant lozenge. Only rare geochronological evidence of later events can be resolved in recrystallised monazite rims dated at 1234. ±. 17. Ma.

Original languageEnglish
Pages (from-to)1-21
Number of pages21
JournalPrecambrian Research
Volume240
DOIs
Publication statusPublished - Jan 2014
Externally publishedYes

Fingerprint

monazite
granulite
magmatism
Proterozoic
metamorphism
Rocks
zircon
granulite facies
Cooling
cooling
protolith
rock
leucosome
closure temperature
Garnets
Tectonics
heat source
Crystallization
mafic rock
heat flow

Cite this

Clark, Chris ; Kirkland, Christopher L. ; Spaggiari, Catherine V. ; Oorschot, Chris ; Wingate, Michael T.D. ; Taylor, Richard J. / Proterozoic granulite formation driven by mafic magmatism : An example from the Fraser Range Metamorphics, Western Australia. In: Precambrian Research. 2014 ; Vol. 240. pp. 1-21.
@article{996ebc1ce15f41b5b5a014fd47082bfb,
title = "Proterozoic granulite formation driven by mafic magmatism: An example from the Fraser Range Metamorphics, Western Australia",
abstract = "Elevated heat flow and mafic magmatism during lithospheric extension have often been invoked as a mechanism to drive high-temperature low-pressure metamorphism that produces granulite facies mineral assemblages. Typically, however, evidence of the contemporaneous heat source, such as coeval mafic magmatism, is absent. In this study, we present pressure-temperature (P-T) pseudosection analysis combined with U-Pb isotopic data from zircon and monazite that constrain both the conditions and timing of granulite facies metamorphism in the Fraser Range Metamorphics of the Albany-Fraser Orogen in southern Western Australia. These results also elucidate the extremely rapid timing of, sequentially, deposition of sedimentary protoliths, mafic magmatism, partial melting, and metamorphism within the Fraser Zone during the Mesoproterozoic. The youngest detrital zircons, together with the magmatic ages of intrusive rocks, constrain the depositional age of the protoliths to the Fraser Range Metamorphics to between 1334 and 1293. Ma. Peak metamorphic conditions at c. 1290. Ma were c. 850. °C at pressures of 7-9. kbar. Peak metamorphism was followed by a period of isobaric cooling at pressures of c. 9. kbar. U-Pb zircon ages from leucosomes and metamorphic overgrowths in the metapelitic rocks indicate crystallization of partial melts at 1290. Ma, essentially coincident with the emplacement of mafic rocks at 1292. Ma. In situ analyses of both matrix hosted monazite and monazite inclusions in garnet yield ages between 1285 and 1268. Ma, with no significant age difference between monazite in the two textural positions. Cooling of the Fraser Zone below the Rb-Sr biotite closure temperature (~400. °C) occurred at 1260. Ma. Cooling and strengthening of the Fraser Zone rendered it less susceptible to subsequent tectonic events that affected rocks to the north and south of this resistant lozenge. Only rare geochronological evidence of later events can be resolved in recrystallised monazite rims dated at 1234. ±. 17. Ma.",
keywords = "Granulites, Mafic magmatism, Monazite, Pseudosection modelling, Zircon",
author = "Chris Clark and Kirkland, {Christopher L.} and Spaggiari, {Catherine V.} and Chris Oorschot and Wingate, {Michael T.D.} and Taylor, {Richard J.}",
year = "2014",
month = "1",
doi = "10.1016/j.precamres.2013.07.024",
language = "English",
volume = "240",
pages = "1--21",
journal = "Precambrian Research",
issn = "0301-9268",
publisher = "Pergamon",

}

Proterozoic granulite formation driven by mafic magmatism : An example from the Fraser Range Metamorphics, Western Australia. / Clark, Chris; Kirkland, Christopher L.; Spaggiari, Catherine V.; Oorschot, Chris; Wingate, Michael T.D.; Taylor, Richard J.

In: Precambrian Research, Vol. 240, 01.2014, p. 1-21.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Proterozoic granulite formation driven by mafic magmatism

T2 - An example from the Fraser Range Metamorphics, Western Australia

AU - Clark, Chris

AU - Kirkland, Christopher L.

AU - Spaggiari, Catherine V.

AU - Oorschot, Chris

AU - Wingate, Michael T.D.

AU - Taylor, Richard J.

PY - 2014/1

Y1 - 2014/1

N2 - Elevated heat flow and mafic magmatism during lithospheric extension have often been invoked as a mechanism to drive high-temperature low-pressure metamorphism that produces granulite facies mineral assemblages. Typically, however, evidence of the contemporaneous heat source, such as coeval mafic magmatism, is absent. In this study, we present pressure-temperature (P-T) pseudosection analysis combined with U-Pb isotopic data from zircon and monazite that constrain both the conditions and timing of granulite facies metamorphism in the Fraser Range Metamorphics of the Albany-Fraser Orogen in southern Western Australia. These results also elucidate the extremely rapid timing of, sequentially, deposition of sedimentary protoliths, mafic magmatism, partial melting, and metamorphism within the Fraser Zone during the Mesoproterozoic. The youngest detrital zircons, together with the magmatic ages of intrusive rocks, constrain the depositional age of the protoliths to the Fraser Range Metamorphics to between 1334 and 1293. Ma. Peak metamorphic conditions at c. 1290. Ma were c. 850. °C at pressures of 7-9. kbar. Peak metamorphism was followed by a period of isobaric cooling at pressures of c. 9. kbar. U-Pb zircon ages from leucosomes and metamorphic overgrowths in the metapelitic rocks indicate crystallization of partial melts at 1290. Ma, essentially coincident with the emplacement of mafic rocks at 1292. Ma. In situ analyses of both matrix hosted monazite and monazite inclusions in garnet yield ages between 1285 and 1268. Ma, with no significant age difference between monazite in the two textural positions. Cooling of the Fraser Zone below the Rb-Sr biotite closure temperature (~400. °C) occurred at 1260. Ma. Cooling and strengthening of the Fraser Zone rendered it less susceptible to subsequent tectonic events that affected rocks to the north and south of this resistant lozenge. Only rare geochronological evidence of later events can be resolved in recrystallised monazite rims dated at 1234. ±. 17. Ma.

AB - Elevated heat flow and mafic magmatism during lithospheric extension have often been invoked as a mechanism to drive high-temperature low-pressure metamorphism that produces granulite facies mineral assemblages. Typically, however, evidence of the contemporaneous heat source, such as coeval mafic magmatism, is absent. In this study, we present pressure-temperature (P-T) pseudosection analysis combined with U-Pb isotopic data from zircon and monazite that constrain both the conditions and timing of granulite facies metamorphism in the Fraser Range Metamorphics of the Albany-Fraser Orogen in southern Western Australia. These results also elucidate the extremely rapid timing of, sequentially, deposition of sedimentary protoliths, mafic magmatism, partial melting, and metamorphism within the Fraser Zone during the Mesoproterozoic. The youngest detrital zircons, together with the magmatic ages of intrusive rocks, constrain the depositional age of the protoliths to the Fraser Range Metamorphics to between 1334 and 1293. Ma. Peak metamorphic conditions at c. 1290. Ma were c. 850. °C at pressures of 7-9. kbar. Peak metamorphism was followed by a period of isobaric cooling at pressures of c. 9. kbar. U-Pb zircon ages from leucosomes and metamorphic overgrowths in the metapelitic rocks indicate crystallization of partial melts at 1290. Ma, essentially coincident with the emplacement of mafic rocks at 1292. Ma. In situ analyses of both matrix hosted monazite and monazite inclusions in garnet yield ages between 1285 and 1268. Ma, with no significant age difference between monazite in the two textural positions. Cooling of the Fraser Zone below the Rb-Sr biotite closure temperature (~400. °C) occurred at 1260. Ma. Cooling and strengthening of the Fraser Zone rendered it less susceptible to subsequent tectonic events that affected rocks to the north and south of this resistant lozenge. Only rare geochronological evidence of later events can be resolved in recrystallised monazite rims dated at 1234. ±. 17. Ma.

KW - Granulites

KW - Mafic magmatism

KW - Monazite

KW - Pseudosection modelling

KW - Zircon

UR - http://www.scopus.com/inward/record.url?scp=84887812599&partnerID=8YFLogxK

U2 - 10.1016/j.precamres.2013.07.024

DO - 10.1016/j.precamres.2013.07.024

M3 - Article

VL - 240

SP - 1

EP - 21

JO - Precambrian Research

JF - Precambrian Research

SN - 0301-9268

ER -