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In Tunisia,five Bahloul spaced sections,Bargou,Jerisa,Guern Halfaya,Kherij and Gafsa were analyzed for biostratigraphy(foraminifera and radiolarians) and major and trace elements.This high-resolution biostratigraphic and chemostratigraphic integrated analyses for the Late Cenomanian-Early Turonian Bahloul Formation provide new insight into the palaeoceanographic evolution of the southern Tethyan margin.Relative low abundance of related terrigenous Ti/Al and K/ Al ratios and enrichment of some productivity proxies such as Ba,Cu,and Ni(organic matter related trace elements) suggests that the Bahloul,deposited during a relatively short period(0.5 Ma),was of relatively elevated primary productivity and minimal detrital input.While higher D* values concurrent with lower Ti/Al ratios are interpreted as caused by enhanced fluvial material contribution, due to more humid climate during the OAE-2.Enhanced humidity triggered probably fluvial influxes, resulted in a sluggish water circulation and consequent anoxic/euxinic conditions favoring the preservation of organic matter at the bottom.Enrichments in redox-sensitive trace metals U,V,and Mo in the Bahloul Formation deposits and redox indices,such as V/(V+Ni),U/Th,V/Cr,and Ni/Co, indicate that oxygen-restricted conditions prevailed during the Late Cenomanian to earliest Turonian times and correlate well with relative abundances of some foraminiferal and radiolarian paleo-environmental relevant indicators.High Ba_(xs) values and U_(auth) may indicate anoxic conditions at least at the water-sediment interface during the Bahloul Formation deposition and provide information about low to moderate sulfate-reduction reactions.
In Tunisia, five Bahloul spaced sections, Bargou, Jerisa, Guern Halfaya, Kherij and Gafsa were analyzed for biostratigraphy (foraminifera and radiolarians) and major and trace elements. This high-resolution biostratigraphic and chemostratigraphic integrated analyzes for the Late Cenomanian-Early Turonian Bahloul Formation provide new insight into the palaeoceanographic evolution of the southern Tethyan margin. Relative low abundance of related terrigenous Ti / Al and K / Al ratios and enrichment of some productivity proxies such as Ba, Cu, and Ni (organic matter related trace elements) that the Bahloul, deposited during a relatively short period (0.5 Ma), was of relatively elevated primary productivity and minimal detrital input. While higher D * values concurrent with lower Ti / Al ratios are interpreted as caused by enhanced fluvial material contribution, due to More humid climate during the OAE-2.Enhanced humidity triggered probably fluvial influxes, resulted in a sluggish water circulation consequent anoxic / euxinic conditions favoring the preservation of organic matter at the bottom. Enrichments in redox-sensitive trace metals U, V, and Mo in the Bahloul Formation deposits and redox indices, such as V / (V + Ni), U / Th , V / Cr, and Ni / Co, indicate that oxygen-restricted conditions prevailed during the Late Cenomanian to earliest Turonian times and correlate well with relative abundances of some foraminiferal and radiolarian paleo-environmental relevant indicators. High Ba x (xs) values and U_ (auth) may indicate anoxic conditions at least at the water-sediment interface during the Bahloul Formation deposition and provide information about low to moderate sulfate-reduction reactions.