کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8959359 1646308 2018 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
U-Pb detrital zircon ages of sediments from the Firgoun and Niamey areas (eastern border of West African Craton, West Niger)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
U-Pb detrital zircon ages of sediments from the Firgoun and Niamey areas (eastern border of West African Craton, West Niger)
چکیده انگلیسی
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.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Comptes Rendus Geoscience - Volume 350, Issue 6, September–October 2018, Pages 267-278
نویسندگان
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