الفهرس 
GEOMORPHOLOGY AND GEOLOGY..Only 14 pages are availabe for public view
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Abstract
dunes and interdune sediments in five districts. Also, monthly dustfall samples were collected from
twelve sites in and around Al-Ain city throughout a period of four seasons starting December 1993.
Both types of samples were subjected to various textural and mineralogical analyses. In addition,
the rates and chemical composition of dustfall samples were determined.
Sand dunes in Al-Ain area are dominantly branching linear or star dunes. They show marked
variations in height and evidences of migration. The dunes are composed of carbonate and sand, the
proportions of which may vary markedly in each district and throughout the study area. Sand grains
are mainly rounded and variably display mechanically- and chemically-formed surface features. The
heavy-mineral assemblage is dominated by opaques and pyroxenes. The grains of a given light or
heavy mineral have the same nature in the various districts.
The interdune areas are in places very broad. Their sediments are made up of variable proportions
of carbonate, gravel, sand, silt and clay. Their mineral characteristics are in many aspects
similar to those of sand dunes. However, the proportions of some minerals and their lateral
variations may differ. Also, they contain a number of evaporitic non-clay and clay minerals.
Generally, the interdune sediments are m uch less mature than the adjacent sand dunes. The maturity
of both types of sediments increases toward the SW of the study area.
There are genetic relationships between sand dunes in the various districts, and between them and
the interdune sediments. Both types of sediments are m ulticyclic being derived essentially from
dunes in other parts of the Arabian Peninsula. However, contributions from the Oman Mountains,
Jabal Hafit and the coast of the Arabian Gulf were significant. Also, authigenesis by groundwater u
nder the prevailing highly evaporitic conditions played an impcmant role in the form ation of the
interdu ne sediments.
The environmental studies revealed a relativel y complicated situation in Al-Ain city, which lies
in an arid and/or semiarid desen region. Both natural and man-induced sources of pollution
contribute much to such a situation. Effective control measures should be taken now to abate this
type of pollution before the situation gets more complicated by the future anticipated atmospheric
contaminants.