Advertisement

The Dolomitization in the Deltaic System of Meloussi Formation (Upper Berriasian-Valanginian) in Jebel Meloussi (Central Tunisia)

  • Najwa KhlifiEmail author
  • Jamel Touir
  • Anna Travé
Conference paper
Part of the Advances in Science, Technology & Innovation book series (ASTI)

Abstract

The present work aims at studying the dolostones of the Meloussi Formation (Upper Berriasian-Valanginian) in Jebel Meloussi (Central Tunisia) which is considered as a paleodeltaic system M’Rabet [1]. The study is based on the analysis of dolostones sampled along the Khanguet Zebbag section. Various analyses have been achieved on the dolomite samples in order to reconstruct the environment and the mechanisms of dolomitization. The dolostones include alternating regressive sandy dolomites and transgressive fossiliferous dolomites. The optic microscope and SEM observations show three main petrotypes of dolomite: replacive dolomicrite (P1) associated to the sandy dolostones beds, recrystallized subhedral dolomicrosparite (P2) and cementing euhedral dolosparite (P3) associated to the fossiliferous dolostones. The P1 petrotype resulted from mixing waters dolomitization during the regressive intervals and delta progradation as shown by the significant concentration of Fe and Mn and the negative values of δ18O and δ13C. The P2 resulted from a late burial recrystallization but it should have been initially developed in a rather marine environment during the transgressive intervals and the delta retrogradation as testified by the high amount of Sr, Na and Mg versus low amount of Fe and Mn and by the slightly negative δ18O and δ13C. The P3 represents late burial dolomite cement resulting from dolomite precipitation within marine water as attested by the very high concentration of Sr and Na in comparison with those of Fe and Mn and the moderately negative to positive δ18O and δ13C.

Keywords

Dolomite Dolomitization Petrotypes Geochemical and isotopic analyses Paleodelta Meloussi formation Upper Berriasian-Valanginian Jebel meloussi Central tunisia 

References

  1. 1.
    M’rabet, A.: Differentiation of environments of dolomite formation, lower Cretaceous of central Tunisia. Sedimentology 28, 331–352 (1987)CrossRefGoogle Scholar
  2. 2.
    Burollet, P.F.: Contribution à l’étude stratigraphique de la Tunisie Centrale. Ann. Mines Geol, Tunis, N 18, 345 (1956)Google Scholar
  3. 3.
    Gregg, J.M., Sibley, D.F.: Epigenetic dolomitization and the origin of xenotopic dolomite texture. Jour. sedim. Petrology 54(3), 908–931 (1984)Google Scholar
  4. 4.
    Grimaldi, M.H.: Types pétrographiques associés aux différents stades de genèse d’une dolomie tidale polyphasée: la dolomie de Mano. 1er Congrès Français de sédimentologie, Paris, Novembre 1987, pp. 193–194 (1987)Google Scholar
  5. 5.
    Badiozamani, K.: The Dorag dolomitization model-application to the middle ordovician of Wisconsin. J. Sed. Petrology. 43(4), 965–984 (1973)Google Scholar
  6. 6.
    Touir, J., Soussi, M., Troudi, H.: Polyphased dolomitization of a shoal-rimmed carbonate platform: example from the middle Turonian Bireno dolomites of central Tunisia. Cretac. Res. 30(3), 785–804 (2009)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Sfax UniversitySfaxTunisia
  2. 2.Barcelone UniversityBarceloneSpain

Personalised recommendations