Ian Davison (Earthmoves, U.K.) - GEOLOGY AND HYDROCARBON POTENTIAL OF THE NW AFRICAN ATLANTIC MARGIN
Ian Davison is Managing Director of Earthmoves Ltd. which he founded in 1999. Ian received a first degree in Earth Sciences from the University of Leeds, and then went on to complete a PhD on Precambrian mobile belts in Mali, NW Africa at Montpellier and Leeds Universities. After this, he joined the British National Oil Company in Glasgow for three years where he was involved in International Exploration in NW Europe. He then moved to Salvador in NE Brazil where he lectured in Basin Dynamics, Tectonics and Precambrian Geology for five years. He returned to the UK in 1989 and became a Senior Lecturer in Structural Geology at Royal Holloway, University of London, where he directed the Salt Tectonics Group. Ian has been involved with consultancy work for oil companies in frontier exploration areas for the last twenty years and has consulted for over 90 diffferent companies. He regularly gives industry short courses on Salt Tectonics and the South Atlantic. He has recently started a second Exploration consultancy company called GEO International ltd. which specialises in geopshysical interpretation and GIS regional evaluations. He has written over 60 publications in international journals.
ABSTRACT
GEOLOGY AND HYDROCARBON POTENTIAL OF THE NW AFRICAN ATLANTIC MARGIN
Davison, Ian 1
1Earthmoves Ltd. Chartley, 38-42 Upper Park Road, Camberley, Surrey, Gu15 2EF, United Kingdom
TheNW African Atlantic Rift System began to open in Carnian times (ca. 235 Ma) and produced a series of half graben withred-bed clastic fill in Morocco. Near the end of rifting 1-2 km thick salt was deposited, and is interpreted to be the same age as the CAMP volcanics (200+1 Ma).Farther south, the deep Triassic rifts have not been drilled, but they could contain good oil prone source rocks similar to the southern USA basins.New evidence will be presented that salt is present along the Cap Boujdour area of Aaiun Basin 450 km farther to the south of present mapped salt limit. The salt on the North American margin may also extend farther south link South Georges Basin with the Baltimore Canyon Stone Dome occurrence. The northern, limit of the Moroccan salt basin is currently mapped to terminate at the overthrust southern edge of the Rif Thrust Belt, but the salt must continue northward below the Rif. A sub-thrust play exists in Northern Morocco which has never been tested due to the lack of good imaging below the thrust belt. The Cenomanian-Turonian source rock may be mature in this area, due to the tectonic loading in the Oligo-Miocene. The overlying Jurassic sequence is a mainly a carbonate slope facies, but occasionally a rimmed platform edge developed (Senegal, Gambia and Mauritania). The carbonate play has still to be fully tested, because the wells drilled on the USA margin appear to miss the rimmed carbonate edge, and very few wells have drilled the carbonates in NW Africa. The carbonate platform eventually became drowned in the Early Cretaceous clastic deltas were deposited. The increased clastics input may be the due to the internal rifting and flank uplift occurring throughout North Africa. Cretaceous -Cainozoic clastics constitute the main deepwater target reservoirs. Recent wells in Morocco appear to have failed due to lack of reservoir.
