Coupled precambrian crustal evolution and supercontinent cycles: Insights from in-situ U-Pb, O- and Hf-isotopes in detrital zircon, NW India

Wei Wang, Peter A. Cawood, Manoj K. Pandit, Xiao Ping Xia, Jun Hong Zhao

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Oxygen and hafnium isotopic compositions, measured in-situ on U-Pb dated zircon grains from Paleoproterozoic to early Cambrian successions in NW India have implication for regional crustal evolution and supercontinent cycles. Analyzed zircon grains have high Th/U ratios (>0.1), display strongly fractionated REE patterns, metamorphic overprint, and evidence of interaction with low temperature fluids. Their positive Ce and negative Eu anomalies preclude any Pb loss after zircon crystallization. The U-Pb age spectra (concordance between 90 and 110%) indicate prominent peaks at 2.6 to 2.4 Ga, 1.9 to 1.7 Ga, 1.6 to 1.5 Ga, 1.2 to 1.0 Ga and 0.9 to 0.7 Ga that coincide with the assembly and breakup of Precambrian supercontinents. The Hf model ages of zircon grains with mantle like δ 18 O values reveal continuous generation of the continental crust from 3.3 to 1.3 Ga in NW India with major episodes during 3.3 to 2.7 Ga and 1.7 to 1.5 Ga. These ages correspond well with the 3.4 to 2.9 Ga and 2.2 to 1.6 Ga age peaks recognized in detrital zircon populations from eastern Australia and North America, underlining the significance of these time brackets in continental crust generation during the global continental evolution. Magmatic episodes at 1.9 to 1.7, 1.2 to 1.0 and 0.9 to 0.7 Ga are considered to represent crustal reworking rather than juvenile addition and the former two phases correspond with periods of supercontinent assembly. However, a progressive depletion in 18 O from supra-mantle to mantle values in the 1.7 to 1.5 Ga zircons, coupled with their mantle-like Hf(t) values, indicate at least some juvenile input. Moreover, the 1344 to 1120 Ma zircon grains with low δ 18 O (3.7-1.5%) but high Hf(t) (+8.1-+1.9 with one exception of -2.5) values signify rapid reworking of mantle derived materials in an extensional setting during this period. The 0.9 to 0.7 Ga peak, corresponding to the fragmentation of Rodinia supercontinent, documents crustal reworking that is in contradiction to the generally considered juvenile crustal addition in extensional setting associated with supercontinent breakup.

Original languageEnglish
Pages (from-to)989-1017
Number of pages29
JournalAmerican Journal of Science
Volume318
Issue number10
DOIs
Publication statusPublished - 1 Dec 2018

Keywords

  • Crustal evolution
  • Detrital zircon ages
  • NW India
  • Supercontinent cycles
  • U-Pb-Hf-O-isotopes

Cite this

@article{2bcf98af37674717ac986caac2eb6a33,
title = "Coupled precambrian crustal evolution and supercontinent cycles: Insights from in-situ U-Pb, O- and Hf-isotopes in detrital zircon, NW India",
abstract = "Oxygen and hafnium isotopic compositions, measured in-situ on U-Pb dated zircon grains from Paleoproterozoic to early Cambrian successions in NW India have implication for regional crustal evolution and supercontinent cycles. Analyzed zircon grains have high Th/U ratios (>0.1), display strongly fractionated REE patterns, metamorphic overprint, and evidence of interaction with low temperature fluids. Their positive Ce and negative Eu anomalies preclude any Pb loss after zircon crystallization. The U-Pb age spectra (concordance between 90 and 110{\%}) indicate prominent peaks at 2.6 to 2.4 Ga, 1.9 to 1.7 Ga, 1.6 to 1.5 Ga, 1.2 to 1.0 Ga and 0.9 to 0.7 Ga that coincide with the assembly and breakup of Precambrian supercontinents. The Hf model ages of zircon grains with mantle like δ 18 O values reveal continuous generation of the continental crust from 3.3 to 1.3 Ga in NW India with major episodes during 3.3 to 2.7 Ga and 1.7 to 1.5 Ga. These ages correspond well with the 3.4 to 2.9 Ga and 2.2 to 1.6 Ga age peaks recognized in detrital zircon populations from eastern Australia and North America, underlining the significance of these time brackets in continental crust generation during the global continental evolution. Magmatic episodes at 1.9 to 1.7, 1.2 to 1.0 and 0.9 to 0.7 Ga are considered to represent crustal reworking rather than juvenile addition and the former two phases correspond with periods of supercontinent assembly. However, a progressive depletion in 18 O from supra-mantle to mantle values in the 1.7 to 1.5 Ga zircons, coupled with their mantle-like Hf(t) values, indicate at least some juvenile input. Moreover, the 1344 to 1120 Ma zircon grains with low δ 18 O (3.7-1.5{\%}) but high Hf(t) (+8.1-+1.9 with one exception of -2.5) values signify rapid reworking of mantle derived materials in an extensional setting during this period. The 0.9 to 0.7 Ga peak, corresponding to the fragmentation of Rodinia supercontinent, documents crustal reworking that is in contradiction to the generally considered juvenile crustal addition in extensional setting associated with supercontinent breakup.",
keywords = "Crustal evolution, Detrital zircon ages, NW India, Supercontinent cycles, U-Pb-Hf-O-isotopes",
author = "Wei Wang and Cawood, {Peter A.} and Pandit, {Manoj K.} and Xia, {Xiao Ping} and Zhao, {Jun Hong}",
year = "2018",
month = "12",
day = "1",
doi = "10.2475/10.2018.01",
language = "English",
volume = "318",
pages = "989--1017",
journal = "American Journal of Science",
issn = "0002-9599",
number = "10",

}

Coupled precambrian crustal evolution and supercontinent cycles : Insights from in-situ U-Pb, O- and Hf-isotopes in detrital zircon, NW India. / Wang, Wei; Cawood, Peter A.; Pandit, Manoj K.; Xia, Xiao Ping; Zhao, Jun Hong.

In: American Journal of Science, Vol. 318, No. 10, 01.12.2018, p. 989-1017.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Coupled precambrian crustal evolution and supercontinent cycles

T2 - Insights from in-situ U-Pb, O- and Hf-isotopes in detrital zircon, NW India

AU - Wang, Wei

AU - Cawood, Peter A.

AU - Pandit, Manoj K.

AU - Xia, Xiao Ping

AU - Zhao, Jun Hong

PY - 2018/12/1

Y1 - 2018/12/1

N2 - Oxygen and hafnium isotopic compositions, measured in-situ on U-Pb dated zircon grains from Paleoproterozoic to early Cambrian successions in NW India have implication for regional crustal evolution and supercontinent cycles. Analyzed zircon grains have high Th/U ratios (>0.1), display strongly fractionated REE patterns, metamorphic overprint, and evidence of interaction with low temperature fluids. Their positive Ce and negative Eu anomalies preclude any Pb loss after zircon crystallization. The U-Pb age spectra (concordance between 90 and 110%) indicate prominent peaks at 2.6 to 2.4 Ga, 1.9 to 1.7 Ga, 1.6 to 1.5 Ga, 1.2 to 1.0 Ga and 0.9 to 0.7 Ga that coincide with the assembly and breakup of Precambrian supercontinents. The Hf model ages of zircon grains with mantle like δ 18 O values reveal continuous generation of the continental crust from 3.3 to 1.3 Ga in NW India with major episodes during 3.3 to 2.7 Ga and 1.7 to 1.5 Ga. These ages correspond well with the 3.4 to 2.9 Ga and 2.2 to 1.6 Ga age peaks recognized in detrital zircon populations from eastern Australia and North America, underlining the significance of these time brackets in continental crust generation during the global continental evolution. Magmatic episodes at 1.9 to 1.7, 1.2 to 1.0 and 0.9 to 0.7 Ga are considered to represent crustal reworking rather than juvenile addition and the former two phases correspond with periods of supercontinent assembly. However, a progressive depletion in 18 O from supra-mantle to mantle values in the 1.7 to 1.5 Ga zircons, coupled with their mantle-like Hf(t) values, indicate at least some juvenile input. Moreover, the 1344 to 1120 Ma zircon grains with low δ 18 O (3.7-1.5%) but high Hf(t) (+8.1-+1.9 with one exception of -2.5) values signify rapid reworking of mantle derived materials in an extensional setting during this period. The 0.9 to 0.7 Ga peak, corresponding to the fragmentation of Rodinia supercontinent, documents crustal reworking that is in contradiction to the generally considered juvenile crustal addition in extensional setting associated with supercontinent breakup.

AB - Oxygen and hafnium isotopic compositions, measured in-situ on U-Pb dated zircon grains from Paleoproterozoic to early Cambrian successions in NW India have implication for regional crustal evolution and supercontinent cycles. Analyzed zircon grains have high Th/U ratios (>0.1), display strongly fractionated REE patterns, metamorphic overprint, and evidence of interaction with low temperature fluids. Their positive Ce and negative Eu anomalies preclude any Pb loss after zircon crystallization. The U-Pb age spectra (concordance between 90 and 110%) indicate prominent peaks at 2.6 to 2.4 Ga, 1.9 to 1.7 Ga, 1.6 to 1.5 Ga, 1.2 to 1.0 Ga and 0.9 to 0.7 Ga that coincide with the assembly and breakup of Precambrian supercontinents. The Hf model ages of zircon grains with mantle like δ 18 O values reveal continuous generation of the continental crust from 3.3 to 1.3 Ga in NW India with major episodes during 3.3 to 2.7 Ga and 1.7 to 1.5 Ga. These ages correspond well with the 3.4 to 2.9 Ga and 2.2 to 1.6 Ga age peaks recognized in detrital zircon populations from eastern Australia and North America, underlining the significance of these time brackets in continental crust generation during the global continental evolution. Magmatic episodes at 1.9 to 1.7, 1.2 to 1.0 and 0.9 to 0.7 Ga are considered to represent crustal reworking rather than juvenile addition and the former two phases correspond with periods of supercontinent assembly. However, a progressive depletion in 18 O from supra-mantle to mantle values in the 1.7 to 1.5 Ga zircons, coupled with their mantle-like Hf(t) values, indicate at least some juvenile input. Moreover, the 1344 to 1120 Ma zircon grains with low δ 18 O (3.7-1.5%) but high Hf(t) (+8.1-+1.9 with one exception of -2.5) values signify rapid reworking of mantle derived materials in an extensional setting during this period. The 0.9 to 0.7 Ga peak, corresponding to the fragmentation of Rodinia supercontinent, documents crustal reworking that is in contradiction to the generally considered juvenile crustal addition in extensional setting associated with supercontinent breakup.

KW - Crustal evolution

KW - Detrital zircon ages

KW - NW India

KW - Supercontinent cycles

KW - U-Pb-Hf-O-isotopes

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U2 - 10.2475/10.2018.01

DO - 10.2475/10.2018.01

M3 - Article

VL - 318

SP - 989

EP - 1017

JO - American Journal of Science

JF - American Journal of Science

SN - 0002-9599

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