Kharaib Fm
Type Locality and Naming
Q.P.C. Well Kharaib No. 1, lat 25°27’09” N, long. 51°11’56” E, elevation 41 m (136 ft), completed 29.6.1953, between drilled depths 1125 and 1208 m (3689 and 3962 ft). W. Sugden, 1953 (unpublished report)
Synonym:
Reference Section:
Lithology and Thickness
Top. 1. Limestone, light grey, fine grained, porous, partly crystallised. 24 m (79 ft). 2. Limestone, grey to cream, porous to compact, detrital, in parts with large pellets, interbedded with argillaceous limestone. 41 m (136 ft). 3. Limestone, light grey, porous, fine grained. 18 m (58 ft). Base. Its thickness is 83 m (273 ft).
Relationships and Distribution
Lower contact
Lekhwair Fm; contact apparently conformable but, regionally, considerable cut-out and condensation of beds beneath the Kharaib Fm can be demonstrated over the Qatar arch. Boundary placed at the contact of limestones of the basal Kharaib Fm, above, with marls or shales of the Lekhwair Fm, below.
Upper contact
Hawar Fm; contact conformable. At contact of marl and shale of the Hawar, above, with limestones of the upper Kharaib Fm, below.
Regional extent
Throughout onshore and offshore Qatar and the Trucial States. Probably extends some distance to the west of Qatar where its equivalent is to be found within the Biyadh Fm.
GeoJSON
Fossils
In 1. Orbitolina discoidea Gras, var. delicata Henson, Dictyoconus arabicus Henson. In 2. O. discoidea var. delicata, Choffatella decipiens Schlumberger. In 3. O. discoidea var. delicata, D. arabicus
Age
Depositional setting
Additional Information
This, predominantly limestone, unit can be traced over a vast area of S.E. Arabia, as a continuous carbonate development typified by the occurrence of Orbitolina discoidea, associated at two levels with Dictyoconus arabicus. In Abu Dhabi the Kharaib Formation includes the Zone B plus Zone C Reservoirs of the Thamama Group limestones, which contains important oil accumulations (G.M. Hajash, 1967).
To the east of Qatar, the marls and shales of the Ratawi Formation, which underlies the Kharaib, pass into a predominantly limestone facies. In offshore Qatar the name Kharaib has been applied to the complete sequence which underlies the Hawar Shale Formation and overlies the Yamama Formation (J.K. Dominguez, 1965). This application of the name is contrary to majority practise in the area.
The upper and lower members of the formation are probably better developed equivalents of the “First” and “Second Orbitolina Limestones” recorded from the Biyadh Formation of eastern Saudi Arabia (Powers, 1968).