Chapter 11 Evaporitic Environments in Northern Sinai

Abstract

Publisher Summary This chapter presents a study of the Northern Sinai that was performed through the sampling of brines and sediments from the Bardawil lagoon and the adjacent sabkhas. In the Northern Sinai coastal plain, the low rainfall, the high rate of evaporation, and the restricted environment lead to the formation of different types of evaporitic environments. The brines in the main lagoon and the western arm are normal marine brines. The Bardawil lagoon is surrounded at its southern reaches by belts of sabkhas. The lagoon beach sabkhas are connected to the lagoon and are inundated occasionally by lagoon water. The types of evaporitic minerals formed and preserved in these sabkhas depend on the degree of connection between the lagoon and the sabkhas, the salinity of the lagoon water, and the extent of flooding by ground water after rainy periods. To the south of the lagoon beach sabkhas and separated from them by sand dunes are the ancient sabkhas representing an earlier supratidal facies. Two types of brines that are usually related to the sabkha types include normal marine brines and calcium chloride brines, which are formed by the interaction of normal marine brines with the sabkha sediments (mainly calcium carbonates). Seasonal changes in the brine composition are due to dilution by rain and ground waters and the subsequent dissolution of gypsum and halite from the sabkhas sediments.