Date of Award

1998

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Environmental Science

First Advisor

Ahmed A El-Kammar

Second Advisor

Abdel R ahman S. AI-Sharhan

Third Advisor

Ahmed AI-Bershamgy

Abstract

The study focuses on the mineral and chemical composition, the textural characters and environmental assessment of some soils from the UAE. About forty soil samples were collected from AI Ain District and the Eastern Mountain District. Soils in AI Ain and its suburb are strongly influenced by the aeolian sedimentation, while those of the Eastern Mountain are formed in narrow valleys strikingly close to ophiolitic hinterland.

The studied soils· are remarkably impoverished in clay size fraction and clay minerals as well. This is due to the impeded chemical weathering under the prevailing arid climate. Corroborative techniques including X-ray diffraction, infrared spectrometry and petrographic examination were employed in mineral analysis. The main mineral constituents are serpentines, amphiboles, feldspar, quartz, calcite and dolomite, besides minor halite, gypsum, hematite and goethite.

A scheme for calculating the theoretical mineral composition from major chemical analysis data has been adopted. The calculated minerals include; halite, gypsum, calcite, dolomite, quartz, orthoclase, plagioclases and ferromagnesian silicates. The latter are calculated to represent, in an approximate manner, the rather complicated admixture of rock forming silicates such as olivines, pyroxenes and amphiboles. The soils of the Eastern Mountain area are markedly enriched in plagioclases "Ab20-30 An80-70", ferromagnesian silicates and dolomite, whilst those of AI Ain are more calcareous and contain more detrital quartz.

Generally, the studied soils are deficit in essential nutrient elements such as phosphorus. The soils of the Eastern Mountain area suffer of serious toxicity by magnesium and transition metals such as cobalt, nickel and chromium.

The measurements of five radioactive radionuclides in the studied soils point to possible pollution by uranium decay series at the eastern flank of Jabal Hafit. The contamination extends for a distance of about 3km and it is most probably related to the thermal groundwater activity in the area under consideration

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