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Chemistry, Mineralogy and maturity status of Obhor Sabkha, Saudi Arabia

  • Al-Ghamdi M. A. M. 
  • Hossain D. 
  • Mufti A. M. B. 
Article
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Abstract

The mineralogy and pore water chemistry of subsoil of the relatively stronger crustal layer above the watertable and the ground water chemistry at two locations in the coastal clayey sabkha areas of Obhor, Saudi Arabia confirm the predominance of evaporites like halite, gypsum, aragonite and calcite and the trend of progressive sabkhaization from top downwards. Of the two locations studied, Station 1 with higher soluble salts contents (TSS up to 28%) in soil and interstitial water salinity (up to 384,200 mg/l) is in a well developed sabkha and Station 2 with lower TSS and salinity is in a slightly developed sabkha as per the classification of Bahafzallanet al. (1993). Clay mineral montmorillonite was identified as a trace (in bulk powder sample) at 45 cm depth at Station 1 and illite at same depth at Station 2 and further work for clay mineral identification is suggested.

Keywords

Pore Water Total Dissolve Solid Halite Aragonite Saudi Arabia 

Caractéristiques chimiques, minéralogiques et stade d’évolution de la Sebkha D’Obhor (Arabie Séoudite)

Résumé

Dans les secteurs côtiers argileux de la sebkha d’Obhor (Arabie Séoudite), l’étude minéralogique de la couche située sous la croûte durcie, ainsi que la composition chimique de l’eau intersticielle qui y est incluse, de même que la chimie de la nappe elle-même confirment la prédominance des évaporites, telles que l’halite, le gypse, l’aragonite et la calcite et la tendance à «sebkhaïsation» progressive du haut vers le bas. Sur les deux sites étudiés, le premier contenant un pourcentage de sels solubles plus élevé dans le sol (jusqu’à 28 %) et une salinité de l’eau interstitielle également plus forte (jusqu’à 384,2 mg/l) est situé dans une sebkha déjà bien développée, alors que le second, contenant moins de sels solubles et une eau à salinité plus faible, correspond à une sebkha peu développée d’après la classification de Bahafzallah et al. (1993). De la montmorillonite a été identifiée en traces à 45 cm de profondeur dans le premier site et de l’illite à la même profondeur dans le second. L’auteur suggère de poursuivre dans la voie de l’identification des argiles dans le contexte des sebkhas.

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References

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Copyright information

© International Assocaition of Engineering eology 1997

Authors and Affiliations

  • Al-Ghamdi M. A. M. 
    • 1
  • Hossain D. 
    • 1
  • Mufti A. M. B. 
    • 1
  1. 1.Geology, Faculty of Earth SciencesKing Abdulaziz University21441Kingdom of Saudi Arabia

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