Provenance record of Laurentian passive-margin strata in the northern Caledonides: Implications for paleodrainage and paleogeography

Peter A. Cawood, Alexander A. Nemchin, Rob Strachan

Research output: Contribution to journalArticleResearchpeer-review

74 Citations (Scopus)

Abstract

Siliciclastic sequences accumulated along the eastern margin of Laurentia during the late Neoproterozoic to early Paleozoic as a result of the breakup of Rodinia and formation of the Iapetus Ocean. Detrital zircon data show considerable variability in provenance of time-equivalent units that has implications for paleodrainage and paleogeography. Samples from northwest Scotland and northeast Greenland show detrital zircon U-Pb age groupings dominated by Archean and Paleoproterozoic populations consistent with derivation largely from the West Greenland segment of the North Atlantic craton. In Scotland, time-equivalent outboard sedimentary sequences show contrasting Archean and Proterozoic populations, including a substantial ca. 1.1-1.0 Ga component, indicative of derivation from the Grenville orogen to the southwest. These contrasting paleodrainage patterns, consistent with paleocurrent data, must have developed during the early phase of passive-margin thermal subsidence and may have been accentuated by remnant rift shoulders. In Newfoundland and the U.S. Appalachians, time-equivalent sedimentary sequences are located within the hinterland of the Grenville orogen and are dominated by ca. 1.1-1.0 detritus with very few pre-Mesoproterozoic grains. The Grenville deformation front in these areas may have constituted a drainage divide that limited sediment input from the cratonic interior.

Original languageEnglish
Pages (from-to)993-1003
Number of pages11
JournalBulletin of the Geological Society of America
Volume119
Issue number7-8
DOIs
Publication statusPublished - 1 Jul 2007
Externally publishedYes

Keywords

  • Caledonides
  • Detrital zircon
  • Greenland
  • Provenance
  • Scotland
  • U-Pb

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