ABSTRACT
The north-eastern area of the Badia includes the ‘pan handle’ of Jordan which separates Syria from Saudi Arabia and the land which stretches westwards to the major town of Mafraq. The area, the Harra, is distinct from the rest of the Badia further south primarily because of its geology, but also due to its surface and groundwater characteristics. Much of the north-eastern Badia lies on a tertiary basalt pavement which gives rise to a very specific geographical environment. The area is a complicated collage of basalt flows which have, at different times, been extruded from several series of volcanic cones lying along large fault and dyke sequences (Ibrahim 1993). Basalt boulders of different sizes currently dominate the ground surface. The age and mineralogy of the basalts are the prime factors influencing clast size, drainage density, wadi morphologies and slope angles (Allison and Higgitt in press). In addition, it is this basalt plateau which controls the groundwater resources and the Jabal al-Arab, which is almost entirely derived from the basalt, is vitally important in determining the rainfall and subsequently the surface hydrology of the surrounding footslopes.
