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- W2793563921 abstract "The Albian organic-rich successions of the lower part of the Fahdene Formation (Albian to Cenomanian, Tunisia) were studied using sedimentology (analysis of carbonate contents and observation of thin sections), bulk organic geochemistry (Rock-Eval pyrolysis), and molecular biomarker distributions. The selected outcrops cover different structural domains from western central Tunisia (Jebel Hamra) to the Diapir zone or the Tunisian Trough (Koudiat Berkouchia, Jebel Ghazouan and Ain Asker from the southwest to the northeast, respectively). Total Organic Carbon values between 0.17 and 3.43% evidenced the record of the Albian oceanic anoxic events OAE1b and OAE1c in this southern Tethys margin. Rock-Eval data and molecular biomarkers (n-alkanes, steranes and terpanes) revealed thermally mature organic matter (OM) consisting of a mixed Type II/III OM (marine planktonic and continental origins). The abundant tricyclic terpanes, C30 17α(H) Diahopanes, and the regular decrease of homohopanes (C31 to C35) in the terpane series, were also indicative of a high contribution of bacterial OM that had been developed under stagnant dysoxic/anoxic environments. Microscopic thin section observations showed OM-rich micro-laminated mudstone to wackestone microfacies with abundant radiolarian and foraminifera. All of these features point to high surface primary organic productivity (POP) and the installation of an oxygen minimum zone (OMZ) at mid-depth of the Albian Basin. We suggest that the POP was the result of increased rich nutrient surface waters by upwelling and submarine volcanic activity. We integrated organic geochemical analysis with the structural context to explain both the variation in the OM richness and the record of these OAEs. The reactivation of faults limiting tilted blocks during the Aptian-Albian extension associated to the ascension of Triassic evaporites controlled the distribution and the preservation of organic-rich sequences from central-western to northern Tunisia. Therefore, we suggest that, as sea level rose during the Early Albian transgression, the structurally low areas invaded (grabens and inter-diapiric rim-synclines) represent very deep marine basins that lay beneath the OMZ limits. Therefore, the installation of an OMZ only coincided with half-graben structures that were either proximal and/or around the Triassic Diapir horsts. This could be the case of the Jebel Hamra and Koudiat Berkouchia localities during the Early Albian. We further propose that these localities may have recorded the OAE1b in the southern Tethys margin. Furthermore, the oscillations of this OMZ related to fluctuating POP and upwelling nutrient supplies, as well as the continental material supply by intensive weathering and seasonal rainfall, could explain both the facies alternations (marls/marly limestones) and the OM richness fluctuations along each studied section. The OAE1c recorded in the studied sections could result from the expansion of the OMZ all over the deep ramp platform, during the high stand sea level. Towards the extreme northeast part of this basin, the Ain Asker succession spanned the entire Albian stage, belonged to the deeper part of the Tunisian trough, probably below the OMZ limits, and therefore scarcely recorded these events." @default.
- W2793563921 created "2018-03-29" @default.
- W2793563921 creator A5003758042 @default.
- W2793563921 creator A5032706467 @default.
- W2793563921 creator A5033652467 @default.
- W2793563921 creator A5033714590 @default.
- W2793563921 date "2018-05-01" @default.
- W2793563921 modified "2023-10-18" @default.
- W2793563921 title "The Albian oceanic anoxic events record in central and northern Tunisia: Geochemical data and paleotectonic controls" @default.
- W2793563921 cites W1491759843 @default.
- W2793563921 cites W1507201230 @default.
- W2793563921 cites W1620286502 @default.
- W2793563921 cites W1633310309 @default.
- W2793563921 cites W1963526089 @default.
- W2793563921 cites W1965389814 @default.
- W2793563921 cites W1966384168 @default.
- W2793563921 cites W1969568109 @default.
- W2793563921 cites W1972516891 @default.
- W2793563921 cites W1973662203 @default.
- W2793563921 cites W1974198880 @default.
- W2793563921 cites W1975795988 @default.
- W2793563921 cites W1984564975 @default.
- W2793563921 cites W1985118231 @default.
- W2793563921 cites W1985260036 @default.
- W2793563921 cites W1987485956 @default.
- W2793563921 cites W1988583192 @default.
- W2793563921 cites W1991070194 @default.
- W2793563921 cites W1993744917 @default.
- W2793563921 cites W1993870305 @default.
- W2793563921 cites W1996122040 @default.
- W2793563921 cites W1997338331 @default.
- W2793563921 cites W2000563335 @default.
- W2793563921 cites W2002086743 @default.
- W2793563921 cites W2005353275 @default.
- W2793563921 cites W2005991387 @default.
- W2793563921 cites W2008031852 @default.
- W2793563921 cites W2013322551 @default.
- W2793563921 cites W2017353691 @default.
- W2793563921 cites W2018057983 @default.
- W2793563921 cites W2019073579 @default.
- W2793563921 cites W2019391870 @default.
- W2793563921 cites W2019806159 @default.
- W2793563921 cites W2020908447 @default.
- W2793563921 cites W2021801226 @default.
- W2793563921 cites W2024719651 @default.
- W2793563921 cites W2027166815 @default.
- W2793563921 cites W2028896630 @default.
- W2793563921 cites W2030266411 @default.
- W2793563921 cites W2033419401 @default.
- W2793563921 cites W2034015593 @default.
- W2793563921 cites W2036218831 @default.
- W2793563921 cites W2040164579 @default.
- W2793563921 cites W2040278045 @default.
- W2793563921 cites W2043697553 @default.
- W2793563921 cites W2044132451 @default.
- W2793563921 cites W2045386399 @default.
- W2793563921 cites W2047749873 @default.
- W2793563921 cites W2050901080 @default.
- W2793563921 cites W2053080324 @default.
- W2793563921 cites W2053113094 @default.
- W2793563921 cites W2053259135 @default.
- W2793563921 cites W2055434212 @default.
- W2793563921 cites W2055439406 @default.
- W2793563921 cites W2058772564 @default.
- W2793563921 cites W2059131953 @default.
- W2793563921 cites W2060899036 @default.
- W2793563921 cites W2061531591 @default.
- W2793563921 cites W2062564258 @default.
- W2793563921 cites W2063962923 @default.
- W2793563921 cites W2068586964 @default.
- W2793563921 cites W2068706144 @default.
- W2793563921 cites W2069761927 @default.
- W2793563921 cites W2070663943 @default.
- W2793563921 cites W2073802532 @default.
- W2793563921 cites W2074181171 @default.
- W2793563921 cites W2076127137 @default.
- W2793563921 cites W2085401592 @default.
- W2793563921 cites W2085863778 @default.
- W2793563921 cites W2087655589 @default.
- W2793563921 cites W2089194183 @default.
- W2793563921 cites W2089635155 @default.
- W2793563921 cites W2093187134 @default.
- W2793563921 cites W2100410210 @default.
- W2793563921 cites W2106660898 @default.
- W2793563921 cites W2112847122 @default.
- W2793563921 cites W2117930633 @default.
- W2793563921 cites W2119855749 @default.
- W2793563921 cites W2120321494 @default.
- W2793563921 cites W2120805501 @default.
- W2793563921 cites W2126571524 @default.
- W2793563921 cites W2130241233 @default.
- W2793563921 cites W2130375829 @default.
- W2793563921 cites W2147032286 @default.
- W2793563921 cites W2151375251 @default.
- W2793563921 cites W2153653789 @default.
- W2793563921 cites W2166272075 @default.
- W2793563921 cites W2169952663 @default.
- W2793563921 cites W2322787014 @default.