Structural Control on Groundwater Distribution and Flow in Irbid Area, North Jordan

This study aims to evaluate geologic and structural influences on groundwater in Irbid area as an essential resource in that area. This importance increases in the light of the rapid increase in human population, industrial expansion, and agricultural activities. The geology of the area is comprised of Upper Cretaceous limestone, silicified limestone and marly limestone, and all overlain by thick layers of soil. Amman Silicified Limestone and Wadi As Sir Limestone Formations form good aquifers in the study area. The influence of faults and joints on groundwater in the study area is two fold. N-S and NE-SW joints and faults act as drainage channels of groundwater flow and also as aquifers in the area. On the other hand, ESE-WNW normal faults, forming a horst and graben system, form a barrier or semi-barrier to the ground water flow. They are responsible for the dryness of wells in Dayr Yusof, Al Husn Camp, and Huwwarah. All these wells are on the down thrown side of these faults.