Juvenile Aeolian Deposits at Badra Area - Eastern Iraq

Abstract

Badra area represents one of those desertified areas, in which the preliminary stage of aeolian activity is very evident. Nabkha dunes and sand sheets are the major wind formed deposits in the area. Nabkhas or more precisely micronabkhas represent the major dune type which imposes a clear indication of the desertification vitality in the area. Such an area may represent an ideal example of how desertification is acting, whereby a well-vegetated area some three decades ago is turning now to a barren land.These vegetation dunes were studied from the morphological, mineralogical and textural aspects. The special dimensions of these dunes are usually small not exceeding a meter in height and a few meters in length indicating a mild wind action with a predominant NW direction. Ripple marks, and adhesion structures are also noticed.The dune sand samples are mainly formed of silty sand with an average median of 2.56Ø (fine sand), average mean 2.55Ø (fine sand), average standard deviation or sorting 0.55Ø (well to moderately well sorted), and negatively skewed. These parameters reveals a fluvial influence besides the dominant dune action.The light mineral fraction of Badra dune samples composed of quartz, calcite, feldspar, and evaporites as major constituents, while the heavy minerals fraction is dominated by the opaques, chlorites, epidote, garnet, mica, amphiboles, and pyroxenes. Probable sediment sources is greatly controlled by the eastern dune belt that extends from Baiji dunes in the northeast to Chailat dunes in the southeast. The sediments of the nearby alluvial deposits of Tigris river may also have their influence.One of the  most  effective  and  sure remedies  for  the  Badra  area  will  be  the efficient  use  of  the  existing  water  resources, in  which  rain  water harvesting and ground  water  resources  are maintained and used to develop more effective ways of irrigation so that the area can be rejuvenated.

Keywords: Nabkha Dune, Desertification, Heavy Minerals, Statistical Parameters.