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Iran is located in the arid and semi-arid zone of the earth. The presence of many limestone
formations as well as suitable geological conditions have resulted in the formation and
development of vast areas of karstic terrains in this country. As the result of diminishing water
supplies, contamination of alluvial aquifers, increase in population and industrial and agricultural development, the study and exploration of karstic water resources have become increasingly
important. In this study, by using different geophysical logs, the lithology, fracture pattern and points of inflow and outflow in the karstic water wells of Ghasr-e Ghomshe, located in Zagros
region, south-west Iran have been analysed. The logs used are; gamma, neutron-neutron, electric,
gamma-gamma, caliper, temperature, flowmeter and fluid-resistivity. The study of some of the
hydrogeological parameter, especially hydraulic head, shows that the ground water supplies in this karstic area have been mainly confined in two reservoirs with different hydraulic heads. The
difference between the hydraulic heads of these two groung water reservoirs, which are separated
by impermeable marly layers, is approximately determined to be 170 meters