Authors / CoAuthors
Black, L.P. | Withnall, I.W.
Abstract
U-Pb zircon SHRIMP ion-microprobe ages are presented for five Proterozoic igneous rocks from the Georgetown Province of northeastern Queensland. Four of these are interpreted as the igneous crystallisation ages of the Croydon Volcanic Group (1548±18 Ma), Lighthouse Granite (1561±10 Ma), Digger Creek Granite (1554±10 Ma), and Mount Hogan Granite (1549±25 Ma). Most of the zircon within the Forest Home Trondhjemite is apparently xenocrystic, being rounded cores that crystallised at 1650±17 Ma; the time of emplacement is not known with certainty, but is thought to be better represented by a 1553±46 Ma Rb-Sr isochron age. The U-Pb zircon emplacement ages are internally consistent in constraining the age of a prograde, intense tectonothermal event (D2) in the province to 1554±10 Ma. This is about 80 Ma older than a previous estimate for the age of this event, based on the correlation of Rb-Sr whole-rock isochron ages and the development of a penetrative (S2) fabric. The use of that particular Rb-Sr technique in terranes of this type should therefore be treated with considerable caution.
Product Type
nonGeographicDataset
eCat Id
81369
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
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2601
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Keywords
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- GA PublicationJournal
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- QLD
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_External
Publication Date
1993-01-01T00:00:00
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unknown
Topic Category
geoscientificInformation
Series Information
AGSO Journal of Australian Geology and Geophysics 14:4:331-341
Lineage
Unknown
Parent Information
Extents
[-20.0, -16.0, 142.0, 146.0]
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Spatial Resolution
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