Paleocurrent, petrography and provenance analyses of the Ajali Sandstone (Upper Cretaceous), southeastern Benue Trough, Nigeria
1987; Elsevier BV; Volume: 54; Issue: 1-2 Linguagem: Inglês
10.1016/0037-0738(87)90003-0
ISSN1879-0968
Autores Tópico(s)Geological and Geochemical Analysis
ResumoPaleocurrent, petrographic and heavy-mineral analyses of the Ajali Sandstone (Late Cretaceous) in southeastern Nigeria show that the sedimentary rocks on the Santonian Okigwe-Abakaliki anticlinorium provided the major detritus, whereas minor contributions of the eastern Precambrian basement block (Oban massif) are confined along a narrow belt southeast of Alayi in the Afikpo Basin. The sandstones derived from the major sedimentary source are quartz arenites characterized by a zircon-tourmaline heavy-mineral assemblage and a radial paleocurrent pattern which parallels the paleoslope of the provenance. On the other hand, those sands generated from the eastern basement block are arkose and sub-arkose dominated by a garnet-apatite-rutile heavy-mineral assemblage and southwesterly directed paleocurrent modes. The results of this study support the previous hypothesis that most ancient quartz arenites are multicycle in origin.
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