SERIES OF GEOLOGICAL REPORTS ON THE EXPOSED GEO.FORMATIONS IN IRAQ

Abstract

The Ghar Formation is Lower Mioceene in age and might reach Middle Miocene ? . It consists mainly of sandstones , and sandy limestone with some conglomearate horizons . The exposure areas of the Ghar Formation are restricted to the southern desert , south of Al – Nasiriya and Samawa ,and in the western desert , north of Muger Al-Dheeb extending southwestwards to wadi Horan and about 10 km more southwestwards . The thickness of the Ghar Formation in surface sections is less than those in subsurface . It ranges from 6m to 50 m in north of Busaiya and wadi Ratga,respectively .In subsurface sections it ranges from 30 m to 343 m in Dujaila / 1 and Nahr Umr/2 . The Ghar Formation is mainly underlain unconformably by the Dammam and Ratga Formations. However, locally it is underlain by Shaik Alas , Shurau , Najmah , Nahr Umr, Mauddud and Rutbah Formations . The upper contact is with Dibdibba and / or Zahra Formation . Locally it is overlain by the Nfayil Formation or interfingers with it ( the upper most part of the Ghar Formation ) . Moreover, the Ghar formation interfingers with the Euphrates Formation . The depositional environment of the Ghar Formation is deltaic . However , locally marine environment is encountered too , when it interfingers with the Euphrates Formation .

From economic point of view the Ghar Formation has no significant importance