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Composition and Origin of the Sabkha Brines, and Their Environmental Impact on Infrastructure in Jizan Area, Red Sea Coast, Saudi Arabia

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Composition and Origin of the Sabkha Brines, and Their Environmental Impact on Infrastructure in Jizan Area, Red Sea Coast, Saudi Arabia Environ Earth Sci (2016) 75:105 DOI 10.1007/s12665-015-4913-6 ORIGINAL ARTICLE Composition and origin of the sabkha brines, and their environmental impact on infrastructure in Jizan area, Red Sea Coast, Saudi Arabia 1 1,2 Mohammed H. Basyoni • Mahmoud A. Aref Received: 2 March 2015 / Accepted: 8 August 2015 Ó Springer-Verlag Berlin Heidelberg 2015 Abstract The sulfate evaporite minerals (gypsum and is of modified marine water having an elevated CaCl2 con- anhydrite) and brines of Jizan sabkha cause corrosion of the tent, which may be derived from dissolution of mixed salt steel reinforcement and deterioration of the concrete, and from the Miocene salt dome in Jizan area. The chemical consequently hinder the development activity for building composition and origin of the brines, and mineralogy and new urban communities and industrial zones in Jizan area, textures of the evaporite minerals in Jizan sabkha help in Red Sea coastal plain of Saudi Arabia. The sabkha evaporite understanding the nature of the corrosive factors to the minerals below the sediment surface are represented by foundations in Jizan area. displacive and inclusive growth of lenticular and rosette gypsum, and nodular anhydrite. In small saline pans, halite Keywords Brine chemistry Á Genesis Á Gypsum Á precipitates form rafts, chevrons and cornets. The salinity Corrosion Á Infrastructure Á Sabkha Á Saudi Arabia (TDS) of the groundwater in the sabkha area is highly vari- able, and ranges from 12,900 to 495,000 mg/l, compared to the average value of the Red Sea water of 40,366 mg/l. The Introduction low salinity values of the sabkha brines are most probably caused by localized influx of groundwater of meteoric origin Sabkhas are ubiquitous geomorphic features in arid and from direct rain fall and/or temporary floods, in addition to semiarid regions where evapotranspiration potentials are seepage of sewage water from septic tanks. The electric very high and the hydrological inputs are conducive to the conductivity (EC) values range from 20,000 to 199,100 lS/ development of endoreic (internal) drainage systems cm which are conformable to the salinity values of the brine. (Goudie and Wells 1995; Shaw and Thomas 1997). They The dominant cation concentration order in seawater represent flat and barren surfaces that are in dynamic and brines of the sabkha is Na? [ Mg2? [ Ca2? [ K?,or equilibrium with eolian deflation and sedimentation con- Na? [ Mg2? [ K? [ Ca2?. The dominant anion concen- trolled by local water table level. Major geotechnical and - 2- - tration order is Cl [ SO4 [ HCO3 . The dominant brine constructional problems, namely, strength loss, differential type for most samples is sodium chloride, with variable settlement, concrete deterioration, and steel corrosion may proportions of the major cations Ca2? and Mg2? and the emerge due to the presence of sabkha (Abou Al-Heija and 2- major anion SO4 . Most brine samples indicate their source Shehata 1989; Shehata et al. 1990; Youssef et al. 2012; Youssef and Maerz 2013). In addition, salt crystallization usually occurs in the concrete pores above the water & Mahmoud A. Aref table leading to their slow disintegration due to the high [email protected] crystallization pressure that is enhanced by evaporation (Al-Amoudi and Abduljauwad 1994; Al-Amoudi et al. 1 Department of Petroleum Geology and Sedimentology, Faculty of Earth Sciences, King Abdulaziz University, 1995). There are three different models that explain the Jeddah, Saudi Arabia sources of the groundwater and solutes in sabkhas. These 2 Geology Department, Faculty of Science, Cairo University, are the ‘‘seawater flooding’’ model that was proposed by Giza, Egypt Kinsman (1969), Butler (1969), and Patterson and Kinsman 123 105 Page 2 of 17 Environ Earth Sci (2016) 75:105 (1977, 1981). The ‘‘evaporative pumping’’ model was Jizan sabkha. The water and brine samples were taken in proposed by Hsu¨ and Siegenthaler (1969); Hsu¨ and Sch- this area from seawater, groundwater, surface shallow pan neider (1973), and McKenzie et al. (1980). The recent or surface excavations in Jizan sabkha (Fig. 1; Tables 1, 2). model of ‘‘ascending brine’’ or ‘‘conceptual’’ model was During the field work, the salinity, temperature and pH proposed by Wood and Sanford (2002), Yechieli and Wood value of the brine in trenches dug in the sabkha were (2002), Wood et al. (2005), and Tyler et al. (2006) for the measured. The salinity was determined by glass hydrom- recent sabkha and most coastal-sabkha environments. In eters taking into account the measuring of standard sea this model, capillary forces bring solutes and water to the water. The hydrometer measures the mass % NaCl in the surface, where the water evaporates and halite and other brine up to 250 %. Temperatures were measured at the soluble minerals are precipitated. Retrograde minerals, surface by mercury thermometer ranging from 0 to 100 °C sensu Wood et al. (2005), such as gypsum, anhydrite, in 0.1 °C divisions. The density of the brine samples was calcite, and dolomite precipitate and accumulate in the measured by using two portable glass hydrometers, the first capillary zone beneath the surface of the coastal sabkha. measures density from 1.00 to 1.10 g/cm3, and the second Sabkha sediments in Jizan area have a negative impact measures density from 1.10 to 1.2 g/cm3. The pH value of on infrastructure causing problems to buildings. The degree the brine was measured in the field by these portable pH- of damage depends on the characteristics of the sabkha, the meters. Thirteen (13) samples (10 samples from sabkha amount of subsidence and the bearing capacity of the brines and 3 samples from the Red Sea water) were sabkha (Shabel 2007). In addition, salt domes offer some chemically analyzed at the Geochemistry Lab, Saudi problems related to underground dissolution in the Jizan Geological Survey, following the procedures given by area, especially in the old city of Jizan. These include Clesceri et al. (1998). The chemical analyses were carried surface collapse, building failure, fractures, tilting, cracked out for the major cations Na?,K?,Ca2?, and Mg2? and the - 2- 2- - roads, undulating ground surface, tilting of posts and major anions HCO3 ,CO3 ,SO4 and Cl . Total dis- electricity poles or even damage of the old buildings and solved solids (TDS) were measured by sample evaporation infrastructure (Erol 1989; Al-Mhaidib 2002; Youssef et al. techniques. Calcium (Ca2?) and magnesium (Mg2?) are 2012; Youssef and Maerz 2013). Most studies carried out determined by compleximetric titration using standard on Jizan sabkha are related to the geotechnical properties of EDTA solution. Chloride (Cl-) is determined by titration - the sabkha soil and the problems related to construction on with standard (0.05 N) AgNO3. Bicarbonate ions (HCO3 ) the sabkha (Dhowian et al. 1987; Dhowian 1990; Erol are determined by titration with standard (0.1 N) HCl. 1989; Al-Shamrani and Dhowian 1997; Al-Mhaidib 2002; Sodium (Na?) and potassium (K?) are measured by flame 2- Shabel 2007; Youssef et al. 2012; Youssef and Maerz photometry. Sulfate ions (SO4 ) are determined colori- 2013). Erol and Dhowian (1988) found severe and wide- metrically using spectrophotometer technique. The ana- spread damage in the settlements of Jizan city, which is lytical precision of the ions is determined by calculating related to sinkholes and to linear depressions associated the absolute error in ionic balance in terms of equivalents with solution channels in the salt dome. The regional per milligram (meq/l), which is found in all samples within composition of the sediments in the Jizan sabkha is the a standard limit of ±5 %. All concentration values were interest of Al-Shamrani and Dhowian (1995, 1997), expressed in milligram per liter (mg/l) unless otherwise Youssef et al. (2012), and Youssef and Maerz (2013). indicated. The chemical data on the major cations and The objectives of the present paper are: (1) identification anions were displayed in graphical forms of the Trilinear of the evaporite mineral composition and textures of the Piper and Sulin diagrams to delineate the composition and sabkha sediments, (2) understanding the hydrochemistry, origin of the brines in the sabkha. brine evolution and genesis of Jizan sabkha, and (3) understanding the effect of brine and evaporite minerals to building failure in Jizan sabkha. The results can be used to Previous studies interpret the chemistry and source of the brines, formation and textures of gypsum, anhydrite and halite in ancient In the Red Sea coastal plain of Saudi Arabia, most of the sabkha deposits. hydrochemical works are concerned with coastal pollution that resulted from sewage plants and other human inference (Turki 2007; Badr et al. 2009; Basaham et al. 2009). Some Materials and methods works are concerned also with the hydrochemistry of coastal lagoons and supratidal sabkhas in the Red Sea and The present paper is based on the results of 10 days of field Arabian Gulf coasts (e.g., Bahafzullah et al. 1993; Basyoni work and excavation of several shallow trenches down to 1997; Basyoni and Mousa 2009; Al-Shaibani 2013; Taj and the groundwater table (36–150 cm in depth) in the area of Aref 2015). Bahafzullah et al. (1993) classified the sabkha 123 Environ Earth Sci (2016) 75:105 Page 3 of 17 105 b a 13 Jizan 1 Duba NORTH EGYPT SUDI ARABIA SAUDI ARABIA Jeddah RED SEA 12 RED SUDAN SEA Jizan 11 10 0 250 km YEMEN 9 Quaternary surficial deposits 8 Pleistocene basalt Mesozoic & Paleozoic sedimentary rocks 2 7 RED SEA Hijaz-Asir complex 6 Granite pluton Proterozoic rocks 5 4 3 Seawater sample Wet mudflat/sandflat Brine sample 0 3km Dry mudflat/sandflat 5 Sample number Miocene salt dome Fig. 1 Surface sediments in Jizan sabkha and geologic setting of Jizan area. (a) Surface sediments and location of seawater and brine samples in Jizan sabkha, (b) Geology of Jizan area (After Blank et al.
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