Geology and Hydrocarbon Potential of the Hamada and Murzuq Basins in Western Libya

Khalil U. Kirmani, Fituri Elhaj

The Hamada and Murzuq intracratonic basins of western Libya form a continuation of the Saharan basin which stretches from Algeria eastward into Tunisia and Libya. The tectonics and sedimentology of this region have been greatly influenced by the Caledonian and Hercynian orogenies. Northwest- and northeast-trending faults are characteristic of the broad, shallow basins.

The Cambrian-Ordovician sediments are fluvial to shallow marine. The Silurian constitutes a complete sedimentary cycle, ranging from deep marine shales to shallow marine and deltaic sediments. The Devonian occupies a unique position between two major orogenies. The Mesozoic strata are relatively thin. The Triassic consists of well-developed continental sands, whereas the Jurassic and Cretaceous sediments are mainly lagoonal dolomites, evaporites, and shales.

Silurian shales are the primary source rock in the area. The quality of the source rock appears to be better in the deeper part of the basin than on its periphery. The Paleozoic has the best hydrocarbon potential. Hydrocarbons have also been encountered in the Triassic and Carboniferous. In the Hamada basin, the best-known field is the El Hamra, with reserves estimated at 155 million bbl from the Devonian.

Significant accumulations of oil have been found in the Silurian. Tlacsin and Tigi are two fields with Silurian production.

In the Murzuq basin the Cambrian-Ordovician has the best production capability. However, substantial reserves need to be established before developing any field in this basin.

Large areas still remain unexplored in western Libya.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.