Abstract: Somalia: A Future Exploration Objective

M. J. Brady, J. C. Harms, J. D. Lowell, D. B. Mackenzie

Somalia has been sparsely explored, and several exploration plays with world-class potential remain to be tested. When political stability is reestablished, successful petroleum exploration would greatly assist the country to become economically independent.

Most of Somalia has a Jurassic to Miocene sedimentary section that ranges from 2 to 5 km thick and is divided into six unconformity- or transgression-bounded sequences. Thicknesses of these sequences vary significantly within 9 depositional basins.

Inland, the Jurassic to Tertiary section consists primarily of interbedded platform limestones and shales, locally with evaporites. This section is transitional eastward to deeper water shelf and basinal deposits along the coastal margin. Mesozoic rifts are present in northern Somalia. The early Cretaceous was a time of widespread emergence. Deltas related to major drainages developed in the Late Cretaceous and Tertiary; subsidence led to accumulation of a thick Tertiary section of deltaic and marginal marine deposits in southeastern Somalia.

The main structural elements resulted from rifting of Gondwanaland during the Carboniferous to Jurassic, separation of Madagascar-India in the early Late Jurassic, and opening of the Gulf of Aden in the middle Tertiary. In central and southern Somalia, warping and down-to-the-coast faulting is Late Cretaceous to middle Tertiary in age. In the north, most deformation is related to Gulf of Aden rifting.

Mature, oil-prone source beds combined with potential reservoir rocks and structures occur in a variety of geological settings. Viable exploration plays include rift basins, regional arches, carbonate platform margins, deltaic complexes, and faulted basin margins.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994