Organic matter appraisal of the Lower Eocene (Ypresian) Bou Dabbous Formation in Tunisia
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- 作者：H. Affouri (1)
M. Montacer (2) - 关键词：Organic matter ; Ypresian ; Bou Dabbous formation ; Rock ; Eval ; Biomarkers ; Steranes ; Terpanes ; Anoxic basin ; Water stratification ; Tunisia
- 刊名：Arabian Journal of Geosciences
- 出版年：2014
- 出版时间：December 2014
- 年：2014
- 卷：7
- 期：12
- 页码：5509-5542
- 全文大小：6,198 KB
- 参考文献：1. Abbes Ch (2004) Structurations et évolutions tectono-sédimentaires mésozo et cénozo?ques associées aux accidents reghmatiques à la jonction des marges téthysiennes et nord-africaines (cha?ne Nord-Sud Tunisie centrale). Thèse Doc. Etat, Université Tunis El Manar, Fac. Sc. Tunis, 435 pp
2. Abdeljaouad S (1983) Etude sédimentologique et structurale de la partie Est de la cha?ne nord des chotts. Thèse 3ème cycle univ Tunis II Fac. Sci. de Tunis. 148 p
3. Andrew DH, Bradley DR, David ZJ, Moldowan M, Ulderico B (2001) Upper Oligocene lacustrine source rocks and petroleum systems of the northern Qaidam basin, northwest China. AAPG Bull 85:601-19
4. Anketell JM, Mriheel IY (2000) Depositional environment and diagenesis of the Eocene Jdeir Formation, Gabes-Tripoli Basin, western offshore Libya. J Petrol Geol 23:425-47 CrossRef
5. Anz JH, Ellouz M (1985) Development and operation of the El Garia reservoir, Ashtart field, offshore Tunisia. J Pet Technol, ETAP 37:481-87 CrossRef
6. Bailey HW, Dungworth G, Hardy M, Scull D, Vaughan RD (1989) A fresh approach to the Metlaoui. Actes des IIèmes Journées de Géologie Tunisienne Appliquée à la Recherche des Hydrocarbures, pp 281-07
7. Beavington-Penney SJ, Wright VP, Racey A (2005) Sediment production and dispersal on foraminifera-dominated early Tertiary ramps: the Eocene El Garia Formation, Tunisia. Sedimentology 52:537-69 CrossRef
8. Bédir M (1995) Mécanismes géodynamiques des bassins associés aux couloirs de coulissement de la marge atlasique de la Tunisie: seismo-stratigraphie, seismo-tectonique et implications pétrolières. Thèse Doc. Etat, Université Tunis II, Tunisie, 416 pp
9. Bédir M, Zargouni F, Tlig S, Bobier C (1992) Subsurface geodynamics and petroleum of transform margin basins in the Sahel of Mahdia and El Jem (Eastern Tunisia). AAPG Bull 76(9):1417-442
10. Beji Sassi A, Laaridhi-Ouazaa N, Clocchiati R (1996) Les inclusions vitreuses des ilménites, apatites et quartz des sédiments phosphatés de Tunisie: témoignages d’un volcanisme alcalin d’age paléocène supérieur à éocène. Bull Soc Geol Fr 167:227-31
11. Belayouni H (1983) Etude de la matière organique dans la série phosphatée du bassin de Gafsa-Metlaoui (Tunisie). Application à la compréhension des mécanismes de la phosphatogenèse. Thèse de Doc Etat Univ Orléans (Fr) 202 pp, BRGM Ed. 77
12. Belayouni H, Slansky M, Trichet J (1990) A study of the organic matter in Tunisian phosphate series: relevance to phosphorite genesis in the Gafsa Basin (Tunisia). Org Geochem 15:47-2 CrossRef
13. Belayouni H, Guerrera F, Martin MM, Serrano F (2012) Stratigraphic update of the Cenozoic Sub-Numidian formations of the Tunisian Tell (North Africa): tectonic/sedimentary evolution and correlations along the Maghrebian Chain. J Afri Earth Sci 64:48-4 CrossRef
14. Ben Ayed N (1986-993) Evolution tectonique de l’avant-pays de la cha?ne alpine de Tunisie du début du Mésozo?que à l’Actuel. Thèse Doc. Etat, Univ. Paris-Sud Orsay, France, 328?pp. and Ann. Min. Géol. Tunis, no 32
15. Ben Chelbi M, Melki F, Zargouni F (2006) Mode de mise en place des corps salifères dans l’Atlas septentrional de Tunisie. Exemple de l’appareil de Bir Afou. Compt Rendus Geosci 338:349-58 CrossRef
16. Ben Ismail–Lattrache K (2000) Précision sur le passage lutétien-dans les dép?ts éocènes moyens en Tunisie Centrale et Nord–Orientale. Rev Micropal 43(1-):3-6 CrossRef
17. Ben Jemia M (1986) Evolution tectonique de la zone de failles Trozza-Labe?ed (Tunisie centrale). Thèse 3ème cycle, Univ. Paris-Sud Orsay, Fr, 162 pp
18. Ben Jemia-Fakhfekh H (1991) Les calcaires de l'Eocène inférieur en Tunisie centro-septentrionale: sédimentologie et paléo-géographie. Thèse Univ. Franche-Comté Fr, Besan?on 232 pp
19. Biju-Duval B, Dercourt J, Le Pichon X (1977) From the Tethys Ocean to the Mediterranean Seas: a plate tectonic model of the evolution of the western Alpine system. In: Biju-Duval B, Montadert L (eds) Symposium on the geological history of the Mediterranean basins. Technip, Paris, pp 143-64
2 - 作者单位：H. Affouri (1)
M. Montacer (2)
1. Department of Earth Sciences, LR GEOGLOB (Code 03/UR/10-02), Faculty of Sciences of Sfax, University of Sfax, BP 1171, 3000, Sfax, Tunisia
2. Faculty of Sciences of Gabès, University of Gabès, Gabès, Tunisia - ISSN：1866-7538
文摘
Various facies characterize the Lower Eocene (Ypresian) that had been named formations which include the Bou Dabbous Formation. It is one of the four lateral equivalents of the Metlaoui Group and consists of micrite and marls with abundant planktonic foraminifera (Globigerina). In this paper, we report on the organic matter (OM) analyses of the Bou Dabbous Formation from nine outcrop cross sections in central and northern Tunisia. The total organic carbon (TOC) values and Rock-Eval analysis showed that this formation had preserved type II/III marine OM. Locally, such as at Oueds Sidi Mansour and Bou Jabia, TOC values are very high. These values are reliable to the structural framework (subsiding grabens) during the deposition of the Bou Dabbous Formation. Biomarker (steranes and terpanes) analysis showed that this OM is very rich in these compounds. Our results exposed that the Bou Dabbous Formation OM is represented by an open planctonic to estuarine algal facies with bacterial contribution as revealed by the relative abundance of the C27 (37-3?%), C28 (26-1?%), and C29 (30-4?%) steranes and the dominance of the hopane compounds for all the samples. The good preservation of OM in the Bou Dabbous Formation has been evidenced by the high abundance of gammacerane and the preservation of the C34 and C35 homohopanes in central Tunisia (Oueds Souinia and Sidi Mansour) compared to the northern part (Tellian Atlas). We interpreted that the development of anoxic conditions in central Tunisia had been induced by water stratification of super-salt water under arid and warm climate. These results concord with the structural and the paleogeographic setting where the Bou Dabbous Formation in central Tunisia was deposited in subsiding grabens separated from the open sea by high sills (horst). In northern Tunisia, eastern upwelling waters rich nutriments enhanced primary organic productivity and therefore the development of anoxic conditions. Rock-Eval maximum pyrolysis temperature (T max) values fitting with the interval 425-54?°C show that the OM thermal maturity ranges from immature (central Tunisia), marginally mature (Bizerte region) to the peak of oil generation window (NW Tunisia). We showed that these thermal maturity differentiations were related to the geodynamic evolution that had gone separately central and northern Tunisia. Therefore, the Bou Dabbous formation in central Tunisia had gone subsidence inversion and tendencies to emersion since the Late Eocene epoch and consequently not enough to reach the oil generation window. On the other hand, at the Oligocene–Early Miocene, extensional activity favored dissymmetric subsidence where northern Tunisia (Tellian Atlas) had gone active subsidence associated with high thermal flux in relationship to magmatic activities. Consequently, this feature explains the thermal maturation of the Bou Dabbous OM at this province.