Paleocurrent analysis, petrographic, geochemical and statistical appraisal of Neoproterozoic siliciclastic sediments, NE Voltaian Basin, Ghana: a multidisciplinary approach to paleogeographic reconstruction
Küçük Resim Yok
Tarih
2020
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer Heidelberg
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This study used sedimentary structures, facies analysis, petrographic studies, statistical techniques and geochemical data of the Bombouaka/Gambaga Group of the NE Voltaian Basin, Ghana to decipher the source of the sediments. Field measurements covered the Tossiegou, Poubogou, and Panabako Formations of the Bombouaka/Gambaga Group. The influence of hydraulic sorting was interpreted from the effects of highly resistant heavy minerals (identified in the petrographic studies) from polycyclic sources. Principal component analysis (PCA) was applied to the geochemical data to understand element associations. Two broad facies types were identified; lithofacies and ichnofacies. The lithofacies were observed as (a) asymmetric ripple marks on sandstones, (b) parallel lamination on silty/argillaceous sediments, (c) straight-crested and bifurcated ripples on shales, (d) flute casts and climbing ripples on sandy shales, (e) bipolar herringbone cross-bedding on quartz-rich sandstones, and (f) wavy lamination and cross-bedding on feldspathic sandstones. However, the ichnofacies include onlySkolithoson quartzitic sandstones. The structural analyses suggest that about 85% of the paleocurrents were from NE to SW direction with subordinate directions from WNW to ESE. Based on the predominant paleocurrent directions, the sediments were probably derived from the basement Birimian rocks (metavolcanic and metasedimentary rocks with associated granitoids), previously paleogeographically located in the Amazonian Craton but now eroded, transported and transformed into the Birimian Supergroup from which the Voltaian sediments were derived. The PCA points to similar sources of granitoids and metasedimentary rocks. Therefore, the geochemical results and the PCA interpretations support the paleocurrent structures-inferred sources of the sediments in the NE Voltaian Basin.
Açıklama
Anahtar Kelimeler
Paleocurrent structures, Siliciclastic sediments, Geochemistry, Principal component analysis, Sediment source, Voltaian basin
Kaynak
Journal of Sedimentary Environments
WoS Q Değeri
N/A
Scopus Q Değeri
Cilt
5
Sayı
2
