Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.14/114041
29 Visitors
33 Hits
0 Downloads
- Title
- Detrital zircon ages : improving interpretation via Nd and Hf isotopic data
- Related
- Chemical geology, Vol. 262, Issue 3-4 (2009), p.277-292
- DOI
- 10.1016/j.chemgeo.2009.01.029
- Publisher
- Elsevier
- Date
- 2009
- FoR/RFCD Code(s)
-
040200 Geochemistry
040300 Geology
040600 Physical Geography and Environmental Geoscience
- Author/Creator
- Howard, Katherine E
- Author/Creator
- Hand, Martin
- Author/Creator
- Barovich, Karin M
- Author/Creator
- Reid, Anthony
- Author/Creator
- Wade, Benjamin P
- Author/Creator
- Belousova, Elena A
- Description
- The bulk of sedimentary provenance studies use similarities in the detrital zircon age patterns or “barcodes” in sedimentary systems and potential source regions to make interpretations about palaeogeographic settings. While this “age-only” approach is generally considered to be effective, it is limiting because the timing of zircon growth events may not be unique to specific terrains and important rock forming events may be associated with little zircon growth. To a significant extent these limitations can be overcome by employing additional isotopic data sets such as Sm–Nd and Lu–Hf that provide information on the crustal evolution of the source region, and allow comparisons with sedimentary packages. As an example, the age spectra of detrital zircons in Palaeoproterozoic metasedimentary rocks in the eastern Gawler Craton in southern Australia are virtually identical to the dominant zircon growth timelines in adjacent older domains of the Gawler Craton, presenting a prima facie case that it was the source region. However, whole rock Nd isotopic data indicate that the pre-existing proto Gawler Craton was isotopically too crustally evolved (εNd (₁₈₅₀ Ma) ⁻10) to have supplied the bulk of the sediment to the relatively more juvenile metasedimentary units (εNd (₁₈₅₀ Ma) ⁻1 to ⁻5). In addition, zircon Hf isotopic compositions from ca 2000 Ma detrital zircons in the metasedimentary rocks (εHf (₂₀₀₀ Ma) + 2 to + 5) are significantly more juvenile than 2000 Ma rocks in the adjacent Gawler Craton (εHf (₂₀₀₀ Ma) ⁻2 to ⁻5). The combination of bulk rock Nd and Hf zircon data suggest that the Gawler Craton is not a viable source region for the metasedimentary packages, despite the striking similarity between detrital zircon ages and zircon crystallisation events within the craton.
- Description
- 16 page(s)
- Subject Keyword
- 040200 Geochemistry
- Subject Keyword
- 040300 Geology
- Subject Keyword
- 040600 Physical Geography and Environmental Geoscience
- Subject Keyword
- Provenance
- Subject Keyword
- Proterozoic
- Subject Keyword
- Nd isotopes
- Subject Keyword
- Hf isotopes
- Subject Keyword
- Detrital zircon
- Subject Keyword
- Gawler Craton
- Resource Type
- journal article
- Organisation
- Macquarie University. National Key Centre for Geochemical Evolution and Metallogeny of Continents (GEMOC)
- Identifier
- http://hdl.handle.net/1959.14/114041
- Identifier
- ISSN:0009-2541
- Identifier
- mq-rm-2009002901
- Language
- eng
- Reviewed
