THE REQUIRED PARAMETERS FOR LITHOGEOCHEMICAL SURVEY FOR DISPERSION AUREOLES OF MAIN METALLIC DEPOSITS, ARID EASTERN DESERT, EGYPT MAHMOUD M. HASSAAN Al Azhar University, Cairo, Egypt Several types of metallic mineral deposits are occurring in the arid Eastern Desert of Egypt. These deposits are lead-zinc, manganese, copper, tungsten-molybdenum, gold, tinn molybdenum and yttrium-yterbium-niobium-lanthanum. Lithogeochemical dipersion aureoles related to these deposits were revealed in the Quaternary continental detritus, when regional and detailed stream, and overburden lithogeochemical surveys were undertaken. The investigation identified the optimum conditions and parameters required to undertake lithogeochemical survey for dispersion aureoles of the mentioned mineral deposits. These conditions and parameters are types of the Quaternary overburden, horizon and depth of sampling, size fraction to be analysed, geochemical background and the minimum anomalous content of these ore metals, the parameters of the dispersion aureoles (P, S, C and ð) and type of geochemical dispersion.