الفهرس 
Introduction
Water resourcesOnly 14 pages are availabe for public view
 |  | from | 197 |  |  |
| | | from | 197 | | |
Abstract
The present work is dealing with the recent continental sabkhas of the Moghra oasis. The examined sediments have been classified according to their contents of carbonate, sand and mud. The average percentage of sand varies between 14.00% and 94.68% whereas the average percentage of carbonate range from 1.59% and 51.15%. The average content of mud varies between 1.38% and 75.50%. The carbonate shows clear strong negative correlation with sand and weak positive correlation with mud. Chemical analysis of the (47) sediment samples have shown that : pH values of the water soluble extract (1:5) range from 7.23 to 7.94. Accordingly, the samples are in the range of very weak alkaline samples. Electrical conductivity of water extracts show a wide range, it varies from 3935 mmohs/cm at 25oC to 69031. The total amount of dissolved salts (T.D.S.) values range from 2.56 g/L to 44.40 g/L. Potassium ranges from 39 meq/100 gm to 200 meq/100 gm. Sodium content of water extract for samples ranges from 207 meq/100 gm to 6910 meq/100 gm. Magnesium content ranges from 16 meq/100 gm to 128.5 meq/100 gm. Calcium content of water extract ranges from 129 meq/100 gm to 956.2 meq/100 gm. Chloride content of water extracts ranges from 372 meq/100 gm to 10720 meq/100 gm Sulphate content ranges from 300 meq/100 gm to 2417 meq/100 gm.. Chemical analyses of brines water have shown that : The major cations detected in the water samples are as follows in decreasing order of abundance : Na+ > Mg+2 > K+ > Ca+2. pH values range from 7.31 to 7.38. The E.C. varies from 27.34 x 1000 mmohs/cm at 25oC to 1225 x 1000 mmohs/cm. The light minerals is quartz with subordinate amount of feldspar. The opaque minerals are represented by magnetite, hematite and ilmenite. The non opaque minerals are composed of zircon, rutile, tourmaline, staurolite, kyanite, garnet, epidotes and amphiboles. The main minerals are halite, gypsum, quartz, celestite, calcite and dolomite. Clay mineral assemblage identified in the studied sabkha sediments is composed of illite, kaolinite, attapulgite, montmorillonite and segregated illitemontmorillonite mixed layer. The major hydrodynamic process is possibly the upward migration subsurface of brines from the ground water by capillary action due to evaporation, precipitaling on its way gypsum, occasionally with celestite and later halite near the surface.