U–Pb detrital zircon ages of sediments from the Firgoun and Niamey areas (eastern border of West African Craton, West Niger)

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Moussa Konaté - , Université Abdou Moumouni de Niamey (Author)
  • Yacouba Ahmed - , Université Abdou Moumouni de Niamey (Author)
  • Andreas Gärtner - , Senckenberg Gesellschaft für Naturforschung (Author)
  • Diafarou Alzouma Amadou - , Université Abdou Moumouni de Niamey (Author)
  • Hassan Ibrahim Maharou - , Université Abdou Moumouni de Niamey (Author)
  • Kamayé Tourba - , Université Abdou Moumouni de Niamey (Author)
  • Mandy Hofmann - , Senckenberg Gesellschaft für Naturforschung (Author)
  • Johannes Zieger - , Senckenberg Gesellschaft für Naturforschung (Author)
  • Ulf Linnemann - , Senckenberg Natural Historical Collections Dresden, Senckenberg Gesellschaft für Naturforschung (Author)

Abstract

This study uses field observations and new U–Pb ages of detrital zircon grains from three samples to question the stratigraphic position of the Firgoun and Niamey siliciclastic sediments, presumed to be Neoproterozoic in age. Sharing several lithological similarities with the Late Cryogenian “Triad” of the Taoudenni, Gourma, and Volta basins, the uppermost siliciclastic sediments of the Firgoun and Niamey areas were likely also deposited during this period. This is corroborated by matrix-supported diamictites with faceted or striated pebbles as well as by structures resembling cryoturbation processes. However, the detrital zircon U–Pb age record that we present here for the lowermost deposits of Firgoun and Niamey provides mainly Paleoproterozoic ages, and very few Archean ages, altogether in a range from 1822 ± 9 to 3392 ± 9 Ma. Therefore, the new data only show that the Firgoun and Niamey sediments were deposited before about 1800 Ma. Nevertheless, the U–Th–Pb zircon age data allows examining the possible provenance of the sediments. We show that the latter was likely in the westerly close vicinity of the studied areas. The Archean zircons are likely inherited, and possibly originating from a more westerly source. The nearby source of the Niamey and Firgoun sediments suggests that a high topographic relief was still existing in the south-central part of the West African Craton in the Mid Neoproterozoic.

Details

Original languageEnglish
Pages (from-to)267-278
Number of pages12
JournalComptes Rendus Geoscience
Volume350
Issue number6
Publication statusPublished - 1 Sept 2018
Peer-reviewedYes
Externally publishedYes

Keywords

Keywords

  • Detrital zircon age, Firgoun and Niamey, Taoudenni and Gourma basins, West African Craton