Paleocene sea-level and productivity changes at the southern Tethyan margin (El Kef, Tunisia)
- 作者：Guasti ; Elisa ; Kouwenhoven ; Tanja J. ; Brinkhuis ; Henk ; Speijer ; Robert P.
- 关键词：Organic-walled dinoflagellate cysts ; Benthic foraminifera ; Paleocene ; Paleoenvironment ; Sea-level ; Tethys
- 刊名：Marine Micropaleontology
- 出版年：2005
- 期刊代码：58_03778398
- 类别：ear
- 出版时间：April, 2005
- 卷：55
- 期：1-2
- 页码：1-17
- 文件大小：381 K
摘要
Integrated analysis of quantitative distribution patterns of organic-walled dinoflagellate cysts (dinocysts) and benthic foraminifera from the Paleocene El Kef section (NW Tunisia) allows the reconstruction of sea-level and productivity fluctuations. Our records indicate that the environment evolved from an initially oligotrophic, open marine, outer neritic to upper bathyal setting towards a more eutrophic inner neritic setting, influenced by coastal upwelling by the end of the Paleocene. An overall second order change in paleodepth is reflected by both microfossil groups. From the base of planktic foraminifera Zone P4 onwards, the main phase of shallowing is evidenced by an increase of inner neritic dinocysts of the Areoligera group, disappearance of deeper-water benthic foraminifera and increasing dominance of shallow-marine taxa (several buliminids, Haplophragmoides spp., Trochammina spp.). The total magnitude of this shallowing is obscured by interaction with a signal of eutrophication, but estimated to be around 150 m (from 
200 to 50 m). Superimposed on the overall trend, third order sea-level fluctuations have been identified and correlated to sequences in other regions. Paleoproductivity indicators (notably protoperidinioid dinocysts and buliminids) show a trend from an oligotrophic to a eutrophic setting.
200 to 50 m). Superimposed on the overall trend, third order sea-level fluctuations have been identified and correlated to sequences in other regions. Paleoproductivity indicators (notably protoperidinioid dinocysts and buliminids) show a trend from an oligotrophic to a eutrophic setting.