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Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.14/16736
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- Title
- 3.6 Ga lower crust in central China : new evidence on the assembly of the North China craton
- Related
- Geology, Vol. 32, Issue 3, p.229-232
- DOI
- 10.1130/G20133.1
- Publisher
- Geological Society of America
- Date
- 2004
- Author/Creator
- Zheng, Jianping
- Author/Creator
- Griffin, W. L
- Author/Creator
- O'Reilly, Suzanne Y
- Author/Creator
- Lu, Fengxiang
- Author/Creator
- Wang, Chunyang
- Author/Creator
- Zhang, Ming
- Author/Creator
- Fangzheng, Wang
- Author/Creator
- Li, Huimin
- Description
- U-Pb and Hf isotope analyses of zircons from felsic granulite xenoliths in Mesozoic volcanics reveal Early Archean (≥3.6 Ga) lower crust beneath the younger (<2.85 Ga) southern margin of the North China craton, and suggest that the eastern part of the craton formed a coherent block by 3.6 Ga. Hf model ages indicate extraction of protoliths from the mantle ca. 4 Ga or earlier, followed by remelting at 3.6–3.7 Ga. Hf isotope data require both recrystallization of magmatic zircons, and growth of new zircon, up to ca. 1.9 Ga. One sample records 2.1–1.9 Ga remelting of a 2.5 Ga protolith. If large parts of the exposed upper continental crust elsewhere also are underlain by older lower crust, estimates of crustal growth rates through time will require revision.
- Description
- 4 page(s)
- Subject Keyword
- 040200 Geochemistry
- Subject Keyword
- 040300 Geology
- Subject Keyword
- North China craton
- Subject Keyword
- Hf isotopes
- Subject Keyword
- zircon U-Pb dating
- Subject Keyword
- lower crustal granulites
- Resource Type
- journal article
- Organisation
- Macquarie University. Department of Earth and Planetary Sciences
- Organisation
- Macquarie University. National Key Centre for Geochemical Evolution and Metallogeny of Continents (GEMOC)
- Identifier
- http://hdl.handle.net/1959.14/16736
- Identifier
- mq:2022
- Identifier
- ISSN:0091-7613
- Identifier
- mq-rm-2004020666
- Language
- eng
- Reviewed
Macquarie University ResearchOnline
