|Characterization of the Late Barremian in north central Tunisia: is it a prelude to the oceanic anoxic event 1a?|
In: Journal of African Earth Sciences. Elsevier: Oxford & Amsterdam. ISSN 1464-343X; e-ISSN 1879-1956
Petrography; Mineralogy; Major and trace elements; Carbon and oxygenisotopes; Paleoenvironment
|Auteurs|| || Top |
- Khaled, H.
- Chaabani, F.
- Boulvain, F.
- Mansoura, M.
The Late Barremian-Early Aptian of the Jebel Serdj was studied in detail regarding to lithology, microfacies, mineralogy and geochemistry in order to reconstruct the paleoenvironmental change of the Pre-Selli Event. The studied section is about 37 m-thick and it is consisting of limestone and marlstone interbeds spanning the latest Barremian-Early Aptian.During the latest Barremian, kaolinite/illite intensity ratios show high values possibly indicating a warming trend followed then by decreasing values that may indicate a cooling trend. During the Early Aptian, this cooling trend is reverted into humid/warming trend during the Selli event.During the Late Barremian, the low abundance of Ti/Al and K/Al ratios and the enrichment of some elements such as Ba, Cu and Ni suggests that the studied section is characterized by a high productivity, and a minimal detrital inputs.During the Late Barremian, the δ13C increases sporadically and is associated with enrichments in some redox-sensitive indices U/Th, V/V + Ni, Ni/Co and V/Cr indicating the presence of intermittent dysoxic to anoxic conditions.