During the war and post war years general building construction work was seriously curtailed, due principally to shortages of manpower and materials and the consequent legislative restrictions. However, the general economic recovery throughout Australia and the buoyancy of South Australian economy in particular has given an unprecedented impetus to building construction activity in this State, particularly in Adelaide and its environs. Unfortunately, this accelerated building activity has brought in its train the problem of the supply of raw materials, particularly of suitable building sands and fine aggregates. Present requirements are estimated at approximately 600,000 tons per annum and the demand is rising. Present reserves in known deposits in the immediate vicinity of Adelaide are not sufficiently large to meet this rising demand and ensure continuity of future supplies. Known reserves of good quality building sand which can be used without prior washing are very limited and appear to be confined to ancient stream beds. These ancient stream beds traverse the Adelaide Plains in a meandering fashion between the foothills and the sea coast and probably represent earlier courses of existing streams, such as the Gawler River and Little Para River and possibly also the courses of streams which have no modern counterpart. A study of aerial photographs together with the knowledge that several sand quarries have been worked in the area suggested that the flood plains of the Gawler River, as far South as Virginia and as far North as Two Wells, offered the best chance of locating large deposits of first quality fine concrete aggregate. The area East of the Salisbury-Wakefield railway as far as Angle Vale was considered to be the region most likely to yield material of a suitable grain size. To the West of this area (i.e. towards the coast) the material deposited by the ancient streams is liable to contain a high percentage of the finer fractions of sand, whereas to the East a higher proportion and larger size of gravel can be expected. Further, it is considered likely that towards the coast the ancient streams would have tended to fan out into deltas and thus give rise to shallow, ill defined deposits, whereas further inland the streams would have been confined to deeper, well-defined channels and thus developed deposits which could be more economically worked.