Linking source and sedimentary basin: Detrital zircon record of sediment flux along a modern river system and implications for provenance studies

Peter A. Cawood, Alexander A. Nemchin, Mike Freeman, Keith Sircombe

Research output: Contribution to journalArticleResearchpeer-review

172 Citations (Scopus)

Abstract

U/Pb analysis of detrital zircons from sands along the Frankland River in SW Australia reveal marked downstream changes in their age signatures that correlate with changing basement character. The Archean Yilgarn craton underlies the upper 70% of the river catchment (by area) and detrital zircons from sands in this region are characterized by a unimodal ∼2.7 Ga age signature. The lower part of the river catchment flows over the Mesoproterozoic Albany-Fraser orogen and input from this source results in progressive downstream masking of Yilgarn detritus so that in the most downstream samples this source constitutes only 25% of the detrital zircon age spectrum. The Frankland River age data indicate that the lower portions of the drainage system did not form a non-erosive pathway for sediment flux but rather basement lithologies were a continuing source of sediment yield. This probably reflects rejuvenation and incision of the lower reaches of the river system in response to a drop in baseline and possible sequestering of Yilgarn detritus in upstream reservoirs along the broad open mid-region valleys of the river system. These data emphasize that in ancient orogens, where the link between source and sample site is often not preserved, care needs to be exercised in relating detrital zircon age signature to interpretations of source distribution and paleogeographic reconstructions.

Original languageEnglish
Pages (from-to)259-268
Number of pages10
JournalEarth and Planetary Science Letters
Volume210
Issue number1-2
DOIs
Publication statusPublished - 15 May 2003
Externally publishedYes

Keywords

  • Albany-Fraser orogen
  • Detrital zircon
  • Frankland River
  • Provenance
  • Yilgarn

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