USE OF THE GEOTHERMAL GRADIENT VARIATIONS IN ZONING OF POSTMIOCENE SEQUENCE IN THE NILE DELTA, EGYPT

Among the most important thermal parameters of the rocks and their composing minerals is the Geothermal Gradient. Geothermal gradient plays an important role in expressing the subsurface thermal conditions in any area. After carrying out the required corrections for the thermal data in hand, it was used for estimating and illustrating the Geothermal Gradient variations with depth. Using such results, an attempt was carried out to use such variations to identify the subsurface lithologic compositional variations in the study area based on the thermal characteristics of the different subsurface lithologies.Four main subsurface units were identified and mapped within the Nile Delta.