Geo-electrical Investigation in Harir Plain Northeast of Erbil City

Fadhil A Ghaib

doi:10.33899/earth.2004.37747

Abstract

A total of 32 sites were investigated along three long cross-Alpine trend traverses in part of the Harir plain north of Iraq. Electrical resistivity method was applied. The main task of this study was to investigate the shallow structural and hydrogeological conditions by analyzing in detail the geo-electric sections, along the taken traverses. A set of NW-SE faults was distinguished. Their effect on the groundwater is discussed. A structural map is drawn for the area of study based on electrical data. Also a geologic cross section along one of the traverses was constructed.

Highlights

The studied area occupies about 30km2. It is located in the Harir plain to the south of Harir town about 45km northeast of Erbil City in Iraqi Kurdistan Region (Fig. 1)
The geological reasons are that the limestone of the Bekhme Formation (The main aquifer in northern Iraq) has a very steep dip on the southwestern limb of the Harir Anticline
The stratigraphic succession of the area could be briefed as follows: The oldest rocks cropping out in the area belong to the Bekhme Formation (U.Cretaceous) (Fig.2)

Summary

INTRODUCTION

The stratigraphic succession of the area could be briefed as follows: The oldest rocks cropping out in the area belong to the Bekhme Formation (U.Cretaceous) (Fig.2) This formation makes up the core of both Harir and Shakrok anticlines and is composed of massive or layered dolomitic limestone. In constructing the geo-electric sections of Harir area, dips and locations of the present outcrops relative to the executed traverse were used as guides to extrapolate the boundaries between different electrical horizons. This principle leads to the conclusion that non-porous materials will exhibit relatively high resistivity values since the water content will necessarily be little unless in case of fissuring and fracturing This category includes limestones of Bekhme, Shiranish, Pila Spi and Fat’ha formations. By the extrapolation of the present outcrops based on the geo-electric horizons, resistivity values are concluded for the rock units present in the studied area (Table 2)

Formation name

Karstic dolomitic limestone